STERILISASI C - FILTRASI

STERILISASI C

STERILISASI C

FILTRASI

FILTRASI

KELOMPOK 4

KELOMPOK 4

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BAYYINAH

BAYYINAH

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NURMASARI

NURMASARI

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SEPTI PURNAMA SARI

SEPTI PURNAMA SARI

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SITI MARDIYANTI

SITI MARDIYANTI

FARMASI V A

FARMASI V A

FAKULTAS KEDOKTERAN dan ILMU

FAKULTAS KEDOKTERAN dan ILMU

KESEHATAN

KESEHATAN

UIN SYARIF HIDAYATULLAH JAKARTA

UIN SYARIF HIDAYATULLAH JAKARTA

STERILISASI C (PENYARINGAN)

STERILISASI C (PENYARINGAN)

Farmakope edisi ketiga tahun 1979 Farmakope edisi ketiga tahun 1979 Pen

Penyaryaringingan an larlarutautan n didisarsarining g melmelalualui i penpenyaryarining g bakbakterteri i stesterilril, , didiisiisikankan ked

kedalaalam m wadwadah ah akhakhir ir stesteriril l ,ke,kemudmudian ian ditditutuutup p kedkedap ap memenurnurut ut tektekninikk aseptic.

aseptic.

STERILISASI DENGAN PENYARINGAN

STERILISASI DENGAN PENYARINGAN

Farmakope Indonesia edisi IV yahun 1995 Farmakope Indonesia edisi IV yahun 1995

St

Stererililisisasasi i lalarurutatan n yayang ng lalabibil l teterhrhadadap ap papananas s seseriring ng didilalakukukakann dengan penyaringan menggunakan bahan yang dapat menahan mikroba, dengan penyaringan menggunakan bahan yang dapat menahan mikroba, hingga mikroba yang dikandung dapat dipisahkan secara fisika. Perangkat hingga mikroba yang dikandung dapat dipisahkan secara fisika. Perangkat penya

penyaring umumnya ring umumnya terdterdiri iri dari dari suatsuatu u matrmatriks iks berpoberpori ri bertbertutup utup kedapkedap atau dirangkaikan pada wadah yang tidak permeable. Efektivitas suatu atau dirangkaikan pada wadah yang tidak permeable. Efektivitas suatu penyaring media atau penyaring substrat tergantung pada ukuran pori penyaring media atau penyaring substrat tergantung pada ukuran pori bahan dan dapat tergantung pada daya adsorpsi bakteri pada atau di bahan dan dapat tergantung pada daya adsorpsi bakteri pada atau di dalam matriks penyaring atau bergantung pada mekanisme pengayakan. dalam matriks penyaring atau bergantung pada mekanisme pengayakan. Ada

Ada bebbeberaerapa pa bukbukti ti yanyang g menmenyatyatakaakan n bahbahwa wa penpengaygayakaakan n mermerupaupakankan komponen yang lebih penting dari mekanisme. Penyaring yang melepas komponen yang lebih penting dari mekanisme. Penyaring yang melepas s

seerraatt, , tteerruuttaamma a yayanng g mmeennggaanndduunng g aassbbeess, , hhaarruus s ddiihhiinnddaarrkkaann penggunaannya kecuali tidak ada cara penyaringan alternatif lain yang penggunaannya kecuali tidak ada cara penyaringan alternatif lain yang mu

mungngkikin n didigugunanakakan. n. JiJika ka pepenynyararining g yayang ng mmelelepepas as seserrat at mmememanangg dipe

diperlukrlukan, an, merumerupakan pakan keharkeharusanusan, , bahwa bahwa prosproses es penypenyarinaringan gan melmeliputiputii adany

adanya a penypenyarinaring g yang tidak yang tidak melmelepas serat epas serat dilediletakkatakkan n pada arah pada arah hilhilirir atau sesudah langkah penyaringan awal.

atau sesudah langkah penyaringan awal. Uku

Ukuran ran penpenyaryariningg PePengngukukururan an popororosisitatas s memembmbraran n pepenynyarariningg d

diillaakkuukkaan n ddeennggaan n ppeenngguukkuurraan n nnoommiinnaal l yyaanng g mmeennggggamambbaarrkkaann kem

kemampampuan uan memmembrbran an penpenyaryarining g untuntuk uk memenahnahan an mimikrokroba ba dardari i galgalurur ter

tertententu tu dendengan gan ukuukuran ran yanyang g sessesuaiuai, , bubukan kan dendengan gan penpenetaetapan pan susuatuatu uk

ukururan an rarata ta – – rarata ta popori ri dadan n pepernrnyayatataan an tetentntanang g didiststriribubusi si ukukururanan.. Membran penyaring untuk sterilisasi (yang digunakan untuk memisahkan Membran penyaring untuk sterilisasi (yang digunakan untuk memisahkan seb

men

menahaahan n 100100% % biabiakan kan dardari i 101077 _{mikrmikroba oba galugalurr Pseudomonas diminutaPseudomonas diminuta}

(ATCC 19146) tiap cm

(ATCC 19146) tiap cm22 _{permukaan membran pada tekanan tidak kurangpermukaan membran pada tekanan tidak kurang}

dari 30 psi (2,0 bar). Membran penyaring semacam itu berukuran nominal dari 30 psi (2,0 bar). Membran penyaring semacam itu berukuran nominal 0,

0,22 22 μm μm atatau au 0,0,2 2 μmμm, , tetergrganantutung ng papada da cacara ra pepembmbuauatatan n prprododususenen.. Pengukuran membran penyaring sdapat juga ditentukan untuk pereaksi Pengukuran membran penyaring sdapat juga ditentukan untuk pereaksi at

atau au mmededia ia yayang ng haharurus s didiststererililkakan n dedengngan an carcara a pepenynyarariningagan n (l(lihihatat perlakuan terhadap

perlakuan terhadap Isopropil Miristat Isopropil Miristat  padapada Salep dan Minyak yang Larut Salep dan Minyak yang Larut  dalam Isoprpoil Miristat 

dalam Isoprpoil Miristat  yang tertera padayang tertera pada Uji SterilitasUji Sterilitas <71>). Membran<71>). Membran penya

penyaring ring baktebakteri ri (jug(juga a dikendikenal al sebagsebagai ai membmembran ran penyapenyaring ring analanalitiitik),k), yang hanya mampu menahan mikroba berukuran lebih besar, diberi etiket yang hanya mampu menahan mikroba berukuran lebih besar, diberi etiket dengan ukuran nominal 0,45 μm. Tidak ada satupun cara pengukuran dengan ukuran nominal 0,45 μm. Tidak ada satupun cara pengukuran pe

penynyararining g 0,0,45 45 μm μm yayang ng diditetetatapkpkan an ololeh eh babadadan n beberwrwenenanang, g, dadann pe

pengngukukururan an tetergrganantutung ng kekepapada da cacara ra kokonvnvenensisiononal al dadari ri prprododususenen;; pen

penyaryaring ing 0,40,45 5 μm μm mamampmpu u menmenahaahan n biabiakan kan tertertententu, tu, sepsepertertii SerratiaSerratia marcescens

marcescens (ATCC 14756) atau(ATCC 14756) atau Pseudomonas diminutaPseudomonas diminuta. Tekanan uji yang. Tekanan uji yang digunakan beraneka ragam, mulai dari yang rendah (5 psi, 0,33 bar untuk digunakan beraneka ragam, mulai dari yang rendah (5 psi, 0,33 bar untuk Serratia

Serratia atau 0,5 psi, 0,34 bar untukatau 0,5 psi, 0,34 bar untuk Pseudomonas diminutaPseudomonas diminuta) hingga yang) hingga yang ti

tingnggi gi (5(50 0 pspsi, i, 3,3,4 4 babar)r). . MeMembmbraran n inini i didigugunanakakan n ununtutuk k ujuji i ststererililititasas (menurut

(menurut Prosedur Prosedur seperti yang tertera padaseperti yang tertera pada Uji Menggunakan PenyaringUji Menggunakan Penyaring Membran

Membran dalamdalam Uji Uji SteriSterilitlitasas <71<71>), >), yanyang g tidtidak ak memmemerlerlukaukan n retretensensii mikroba yang sempurna. Kecil kemungkinan untuk melakukan pengujian mikroba yang sempurna. Kecil kemungkinan untuk melakukan pengujian con

contoh toh yanyang g tertercemcemar ar hanhanya ya ololeh eh mimikrokroba ba berberukuukuran ran keckecilil. . MemMembrbranan penyaring berukuran nominal yang sangat kecil dapat

penyaring berukuran nominal yang sangat kecil dapat diuji dengan biakandiuji dengan biakan   Acholeplasma laidlawii

  Acholeplasma laidlawii atau galur lainatau galur lain MycoplasmaMycoplasma pada tekanan 7 psipada tekanan 7 psi (0,7 bar) dan akan berukuran nominal 0,1 μm. Pengukuran nominal yang (0,7 bar) dan akan berukuran nominal 0,1 μm. Pengukuran nominal yang didasarkan pada sifat retensi mikroba berbeda jika pengukuran dilakukan didasarkan pada sifat retensi mikroba berbeda jika pengukuran dilakukan den

dengan gan carcara a lailain, n, umpumpamamanyanya a dendengan gan penpengukgukururan an retretensensi i lilingkngkaraarann lateks dengan berbagai diameter. Merupakan tanggung jawab pengguna lateks dengan berbagai diameter. Merupakan tanggung jawab pengguna untuk memilih suatu penyaring dengan ukuran yang tepat untuk tujuan untuk memilih suatu penyaring dengan ukuran yang tepat untuk tujuan tertentu, tergantung kepada sifat produk yang akan disaring. Umumnya tertentu, tergantung kepada sifat produk yang akan disaring. Umumnya ti

tidadak k lalayayak k ununtutuk k memengngululanang g ujuji i kakapapasisitatas s pepenynyarariningagan n di di tetempmpatat pe

pengnggugunana. . UjUji i tatantntanang g mimikrkroboba a lelebibih h babaik ik didilalakukukakan n ppadada a kokondndisisii produsen terhadap tiap bets

Pemakai harus menetapkan parameter penyaringan yang

Pemakai harus menetapkan parameter penyaringan yang digunakandigunakan dalam pembuatan yang mempengaruhi efisiensi retensi mikroba secara dalam pembuatan yang mempengaruhi efisiensi retensi mikroba secara bermakna. Beberapa hal penting yang harus diperhatikan pada validasi bermakna. Beberapa hal penting yang harus diperhatikan pada validasi pr

prososes es pepenynyarariningagan, n, mmelelipipututi i kekemamampmpuauan n kokompmpatatibibililititas as prprododukuk,, pe

penynyererapapan an obobatat, , pepengngawawet et dadan n atatau au zazat t tatambmbahahan an lalaininnynya, a, ddanan pengeluaran awal kandungan

pengeluaran awal kandungan endotoksin.endotoksin.

Karena efektifitas proses penyaringan juga dipengaruhi oleh beban Karena efektifitas proses penyaringan juga dipengaruhi oleh beban mi

mikrokroba ba lalarutrutan an yanyang g akaakan n didisarsaringing, , penpenetaetapan pan kuakualitlitas as mimikrokrobibioloologigi larutan sebelum penyaringan, merupakan aspek penting validasi proses larutan sebelum penyaringan, merupakan aspek penting validasi proses pen

penyaryaringingan an sebsebagaagai i tamtambahbahan an papada da penpenetaetapan pan parparameameter ter lailain n dardarii pro

prosedsedur ur penpenyaryariningangan, , sepseperterti i tektekanaanan, n, lajlaju u alialir r dan dan karkaraktakterierististik k uniunitt pe

penynyararining. g. CaCara ra lalain in ununtutuk k mmenenguguraraikikan an kekemmamampupuan an pepenanahahananann pen

penyaryaring ing adaadalalah h memenggnggunaunakan kan lolog g ninilai lai redreduksuksi i (LN(LNR). R). UmUmpampamanyanya,a, pen

penyaryaring ing berberukuukuran ran 0,2 0,2 μm μm yanyang g dapdapat at memenahnahan an 101077 _{mikmikroba roba galugalurr}

te

tertrtenentu tu akakan an mememimililiki ki LNLNR R titidadak k kukurarang ng dadari ri 7, 7, papada da kokondndisisi i yayangng ditetapkan.

ditetapkan. Pro

Proses ses stesterirililisassasi i larlarutautan n dendengan gan carcara a penpenyaryaringingan, an, padpada a akhakhir ir –– akhir ini telah menghasilkan tingkat kepuasan yang baru, sebagian besar akhir ini telah menghasilkan tingkat kepuasan yang baru, sebagian besar mer

merupaupakan kan hashasil il perperkemkembanbangan gan dan dan kemkemajuajuan an tektekhnohnolologi gi penpenyaryaringing membran. Kelompok media penyaring ini menjurus ke arah pengendalian membran. Kelompok media penyaring ini menjurus ke arah pengendalian pembakuan dan mutu yang lebih efektif dan juga memberi kesempatan pembakuan dan mutu yang lebih efektif dan juga memberi kesempatan yang lebih luas pada pengguna untuk memastikan karakteristik atau sifat yang lebih luas pada pengguna untuk memastikan karakteristik atau sifat rakitan penyaring sebelum dan sesudah penggunaan. Kenyataan bahwa rakitan penyaring sebelum dan sesudah penggunaan. Kenyataan bahwa pen

penyaryaring ing memmembrbran an adaadalah lah laplapisaisan n tiptipis is polpolimimer er memembmberierikan kan banbanyakyak k

keeuunnttuunnggaann, , ttetetaappi i jjuugga a mmeemmbbeerriikkaan n bbeebbeerraappa a kkeerruuggiiaan n jjiikkaa di

dibabandndiningkgkan an dedengngan an pepenynyararining g tetebabal l sesepepertrti i pepenynyararining g dadari ri babahahann pors

porselen elen atau bahatau bahan masian masir. Karenr. Karena banyak dara banyak dari permui permukaan memkaan membranbran adalah suatu ruangan yang kosong atau ruang terbuka, maka penyaring adalah suatu ruangan yang kosong atau ruang terbuka, maka penyaring ya

yang ng cucukukup p babaik ik didirarakikit t dadan n didiststererililkakan n akakan an mmemembeberirikakan n susuatatuu ke

keununtutungngan an beberurupa pa lalaju ju alalir ir yayang ng titingnggigi. . KeKerurugigian an kakarerena na memembmbrarann um

umumnumnya ya raprapuh, uh, sehsehiningga gga penpentinting g untuntuk uk memenetnetapkapkan an bahbahwa wa rakrakitaitann sudah cukup baik dan membran tidak akan rusak atau pecah selama sudah cukup baik dan membran tidak akan rusak atau pecah selama

per

perakiakitantan, , stesterirililisassasai ai ataatau u selselamama a penpengguggunaanaan. n. RakRakitaitan n wadwadah ah dandan pen

penyaryaring ing yanyang g digdigunaunakan kan perpertamtama a – – tamtama a harharus us didivalvalidaidasi si terterhadhadapap kompatibilitas dan integritas oleh pengguna. Jika terbuka kemungkinan kompatibilitas dan integritas oleh pengguna. Jika terbuka kemungkinan un

untutuk k memencncamampupur r rarakikitatan n dadan n memembmbraran n pepenynyararining g yayang ng didiprprododukuksisi berb

berbagai agai prodprodusen, maka usen, maka kompkompatibiatibilitalitas s dari dari dari rakitan dari rakitan gabugabungan ngan iniini harus lebih dahulu divalidasi. Disamping itu, terdapat beberapa uji yang harus lebih dahulu divalidasi. Disamping itu, terdapat beberapa uji yang harus dilakukan oleh produsen penyaring membran yang pada umumnya harus dilakukan oleh produsen penyaring membran yang pada umumnya tidak diulang lagi oleh pengguna, meliputi uji tantang mikrobiologik. Hasil tidak diulang lagi oleh pengguna, meliputi uji tantang mikrobiologik. Hasil uj

uji i teterhrhadadap ap titiap ap bebets ts mmemembrbran an pepenynyararining g yayang ng didiprprododukuksi si haharuruss diperoleh dari produsen, dan

diperoleh dari produsen, dan didokumentasididokumentasikan oleh pengguna.kan oleh pengguna. P

Penenyayarriing ng uuntntuk uk tutujjuuan an ststereriilliisasasi si umumumumnnya ya didillakaksasannakakanan menggunakan rakitan yang memiliki membran dengan porositas nominal menggunakan rakitan yang memiliki membran dengan porositas nominal 0,2 μm atau kurang, berdasarkan pada pembanding yang telah divalidasi 0,2 μm atau kurang, berdasarkan pada pembanding yang telah divalidasi tidak kurang 10

tidak kurang 1077 _{suspensisuspensi PseudomonPseudomonas as diminutadiminuta (ATCC 19146) tiap cm(ATCC 19146) tiap cm}22

dari luas permukaan penyaring. Media membran penyaring yang tersedia dari luas permukaan penyaring. Media membran penyaring yang tersedia saa

saat t ini ini yaiyaitu tu selseluloulosa sa aseasetattat, , selselululosa osa nitnitratrat, , flufluororokaokarbrbonaonat, t, polpolimimerer akri

akrilik, lik, polipolikarbokarbonat, nat, polipoliesterester, , poli vinil poli vinil klorklorida, ida, vinivinil, l, nilnilon, on, polipolitef tef dandan  juga membran logam, dan ini dapat diperkuat atau ditunjang oleh bahan  juga membran logam, dan ini dapat diperkuat atau ditunjang oleh bahan berserat internal. Rakitan penyaring membran harus diuji untuk integritas berserat internal. Rakitan penyaring membran harus diuji untuk integritas awa

awal l sebsebeluelum m didigungunakaakan, n, dendengan gan ketketententuan uan bahbahwa wa ujuji i tertersebsebut ut titidakdak me

mengnggugunanakakan n vavalilididitatas s sisiststem em ujuji, i, dadan n haharurus s didiujuji i sesesusudadah h prprososeses pe

penynyarariningagan n seselelesasai, i, ununtutuk k memenununjnjukukkakan n babahwhwa a rarakikitatan n pepenynyarariningg m

meemmppeerrttaahhaannkkaan n iinntteeggrriittaas s sseeppaannjjaanng g pprroosseedduur r ppeennyyaarriinnggaann berlangsung. Uji penggunaan khusus adalah uji titik gelembung, uji aliran berlangsung. Uji penggunaan khusus adalah uji titik gelembung, uji aliran udara difusif, uji penahan tekanan, dan uji aliran ke depan. Semua uji udara difusif, uji penahan tekanan, dan uji aliran ke depan. Semua uji harus dikaitkan dengan retensi

harus dikaitkan dengan retensi mikroba.mikroba. PR

PROSOSEDEDUUR R UUJI JI STSTERERILILITITAAS S MMENENGGGUGUNANAKAKAN N PPENENYAYARIRINNGAGANN MEMBRAN

MEMBRAN   Ji

  Jika ka tektekhnihnik k penpenyaryaringingan an memmembrabran n digdigunaunakan kan untuntuk uk bahbahan an caicairr yang dapat diuji dengan cara inokulasi langsung ke dalam media uji, uji yang dapat diuji dengan cara inokulasi langsung ke dalam media uji, uji tidak kurang dari volum dan jumlah seperti yang tertera pada

tidak kurang dari volum dan jumlah seperti yang tertera pada PemilihanPemilihan spesimen uji dan masa inkubasi

Peralatan

Peralatan Unit penyaring membran yang sesuai terdiri dari satuUnit penyaring membran yang sesuai terdiri dari satu perangkat yang dapat memudahkan penanganan bahan

perangkat yang dapat memudahkan penanganan bahan uji secara aseptikuji secara aseptik dan

dan memembmbran ran yanyang g teltelah ah dipdiprosroses es dapdapat at didipinpindahdahkan kan secsecara ara aseaseptipticc untuk inokulasi ke dalam media yang sesuai atau satu perangkat yang untuk inokulasi ke dalam media yang sesuai atau satu perangkat yang dapat ditambahkan media steril ke dalam penyaringnya dan membran di dapat ditambahkan media steril ke dalam penyaringnya dan membran di inkubasi

inkubasi in situin situ. Membran yang sesuai umumnya mempunyai porositas. Membran yang sesuai umumnya mempunyai porositas 0,

0,45 45 μμmm, , dedenngagan n didiamameteter er llebebiih h kkuuraranng g 47 47 mmmm, , dadan n kkececepepatatanan penyaringan air 55 ml sampai 75 ml per menit pada tekanan 70 cmHg. penyaringan air 55 ml sampai 75 ml per menit pada tekanan 70 cmHg. Unit keseluruhan dapat dirakit dan disterilkan bersama dengan membran Unit keseluruhan dapat dirakit dan disterilkan bersama dengan membran seb

sebeluelum m didigungunakaakan, n, ataatau u memembmbran ran dapdapat at didistesteririlkalkan n secsecara ara terterpipisahsah de

dengngan an cacara ra apapa a sasaja ja yayang ng dadapapat t mmemempepertrtahahanankakan n kakarrakakteteririststikik penyaring dan menjamin sterilitas penyaring dan

penyaring dan menjamin sterilitas penyaring dan perangkatnya.perangkatnya.

 Jika bahan uji berupa minyak, membrane dapat disterilkan terpisah, dan  Jika bahan uji berupa minyak, membrane dapat disterilkan terpisah, dan

setelah melalui pengeringan, unit dirakit secara

setelah melalui pengeringan, unit dirakit secara aseptik.aseptik.

Teks Asli

Teks Asli

FILTRATION

FILTRATION

British Pharmacopeia 2005 edisi IV. Publised by The Stationery Office on British Pharmacopeia 2005 edisi IV. Publised by The Stationery Office on be

behahalf lf of of ththe e MeMedidicicine ne anand d HeHealalththcacare re prprododucucts ts ReRegugulalatotory ry AgAgenency cy  (MHRA)

(MHRA) Ce

Certrtaiain n acactitive ve iningrgrededieientnts s anand d prprododucucts ts ththat at cacannnnot ot be be tetermrmininalallyly sterilized may be subjected to a filtration procedure using a filter of a type sterilized may be subjected to a filtration procedure using a filter of a type that has been demonstrated to be satisfactory by means of a microbial that has been demonstrated to be satisfactory by means of a microbial cha

challllengenge e testest t usiusing ng a a suisuitabtable le testest t mimicrocro-or-organganismism. . A A sussuspenpensiosion n of of  Pseudomonas diminuta (ATCC 19146, NCIMB 11091 or CIP 103020) may Pseudomonas diminuta (ATCC 19146, NCIMB 11091 or CIP 103020) may be suitable. It is recommended that a challenge of at least 10

be suitable. It is recommended that a challenge of at least 1077 _{CFU perCFU per}

cm

cm22 _{of active filter surface is used and that the suspension is prepared inof active filter surface is used and that the suspension is prepared in}

tryptone soya broth which, after passage through the filter, is collected tryptone soya broth which, after passage through the filter, is collected aseptically and incubated aerobically at 32

preca

precautioutions. ns. The The prodproductiouction n procprocess ess and and envienvironmronment ent are are desidesigned gned toto mi

mininimimize ze mimicrcrobobiaial l cocontntamamininatatioion n anand d arare e reregugulalarlrly y susubjbjececteted d toto appr

appropriopriate ate stersteriliilizatiozation n procprocess. ess. It It is is recomrecommendmended ed that that the the filtfiltratirationon pr

prococesess s is is cacarrrrieied d ouout t as as clclosose e as as popossssibible le to to ththe e fifillllining g popoinint. t. ThThee operations following filtration are carried out

operations following filtration are carried out under aseptic conditions.under aseptic conditions. Sol

Solutiutions ons are are paspassed sed thrthrouough gh a a bacbacterteria-ia-retretententive ive memmembrbrane ane wiwith th aa nominal pore size of 0,22µm or less or any other type of filter known to nominal pore size of 0,22µm or less or any other type of filter known to have

have equivequivalenalent t proppropertierties es of of bactebacteria ria retenretentiontion. . ApprAppropriopriate ate measmeasuresures are taken to avoid

are taken to avoid loss of solute by adsorption on to loss of solute by adsorption on to the filter and to avoidthe filter and to avoid the

the relreleasease e of of concontamtamininantants s frofrom m the the filfilterter. . AttAttententioion n is is givgiven en to to thethe bioburden prior to filtration, filter capacity, batch size and duration of  bioburden prior to filtration, filter capacity, batch size and duration of  filtration. The filter is not used for a

filtration. The filter is not used for a longer period than has been approvedlonger period than has been approved by validation of the combination of the filter and the product in question. by validation of the combination of the filter and the product in question.  The integrity of an assembled sterilizing filter is verified before use and  The integrity of an assembled sterilizing filter is verified before use and confirmed after use by carrying out tests appropriate to the type of filter confirmed after use by carrying out tests appropriate to the type of filter used and the stage of testing, for example bubble-point, pressure hold or used and the stage of testing, for example bubble-point, pressure hold or diffusion rate tests

diffusion rate tests

Due to the potential additional risks of the filtration method as compared Due to the potential additional risks of the filtration method as compared with other sterilization process, a

with other sterilization process, a prefiltratiprefiltration through a on through a bacteria-retentivebacteria-retentive filter may be ensured by other means.

filter may be ensured by other means.

STERILIZATION BY FILTRATION

STERILIZATION BY FILTRATION

Di

Dianana’a’M M CoColllletett t B.B.PhPhararmm, , PhPhd, d, MRMR.P.Phaharmrms; s; MiMichchaeael l E.E.AuAultltonon B.Pharm, Phd,

B.Pharm, Phd, MR.Pharms. Pharmaceutical practice .1990.Singapore.MR.Pharms. Pharmaceutical practice .1990.Singapore. Ste

Sterirililizatzation ion by by is is a a metmethod permhod permiteited d by by the BP the BP for solutfor solutionions s oror liquids that are not sufficiently stable to withstand the process of heating liquids that are not sufficiently stable to withstand the process of heating in an autoclave as described in chapter 20. Passage through a filter of  in an autoclave as described in chapter 20. Passage through a filter of  appropriate pore size can remove bacteria and moulds although smaller appropriate pore size can remove bacteria and moulds although smaller micro-organisms such as viruses and mycoplasms may not be retained. micro-organisms such as viruses and mycoplasms may not be retained. After filtration the liquid is aseptically distributed into previously sterilized After filtration the liquid is aseptically distributed into previously sterilized co

contntiinnerers s wwhihich ch arare e ththen en sesealaleded. . ThThiis s mmetethohod d hhas as a a nunummbeber r oof f  di

disasadvdvanantatageges s anand d shshouould ld be be usused ed ononly ly fofor r ththosose e prprododucucts ts whwhereree sterilizati

sterilization by on by alternative means is not alternative means is not available.available. FILTER MEDIA

FILTER MEDIA

A sterile filter nominal pore size 22 λm less is

A sterile filter nominal pore size 22 λm less is required ( DHSS 1983,required ( DHSS 1983, BP 19880. Filters containing asbestos or any

BP 19880. Filters containing asbestos or any other mµedium likely to shedother mµedium likely to shed fibres or particles may not be used.

fibres or particles may not be used. MEMBRANE FILTERS

  T

  Thehese se arare e ususuaualllly y ththe e prprefefererrered d tytype pe of of fifiltlter er fofor r ststererililizizatatioion.n. Membrane filters are made fro cellulose derivatives or other polymers and Membrane filters are made fro cellulose derivatives or other polymers and there are no loose fibres or particles. The retention of particles larger thn there are no loose fibres or particles. The retention of particles larger thn the pore size occurs on the filter surface which also makes this type of  the pore size occurs on the filter surface which also makes this type of  filter particularly useful for the detection of

filter particularly useful for the detection of bacteria.bacteria. Advantages of membrane filters include: Advantages of membrane filters include: 1.

1. RigRigid structid structure-unure-unaffectaffected by bubbles or presed by bubbles or pressure sursure surges.ges. 2.

2. High flHigh flow ratesow rates-80% of fil-80% of filter surfter surface consiace consists of porsts of pores.es. 3.

3. NoNon-fn-fibribre e shsheddeddinging.. 4.

4. MiniMinimal absmal absorptorption-cion-concenoncentrattration unafion unaffectedfected 5.

5. MiniMinimal wasmal wastage-tage-littlittle retenle retention of soltion of solutioution.n. 6.

6. TestaTestable pble priorior to anr to and after d after filtfiltratiration.on.

Although re-useable membrane filter are available, the disposable Although re-useable membrane filter are available, the disposable types are generally preferred.

types are generally preferred. The use of a

The use of a pre-filter pre-filter 

Membrane filters are generally blocked by particles close in size to Membrane filters are generally blocked by particles close in size to the pore size of the filter. Pre-filtration reduces the risk of blockage of the the pore size of the filter. Pre-filtration reduces the risk of blockage of the final filter. Since the filtration method of sterilization carries a potentially final filter. Since the filtration method of sterilization carries a potentially greater risk of failure than other methods, a second filtration through a greater risk of failure than other methods, a second filtration through a sterilized membrane filter provides an a

sterilized membrane filter provides an additional safeguard.dditional safeguard. Sintered glass filters

Sintered glass filters S

Siinntteerreed d ggllaasss s ffiilltteerrs s mmaadde e ffrroommbboorroossiilliiccaatte e ggllaasss s wwiitthh anappropriate pore size may be

anappropriate pore size may be used to sterilize solutions. These have theused to sterilize solutions. These have the disadvantages of slowness of filtration, fragility and difficulty of cleaning. disadvantages of slowness of filtration, fragility and difficulty of cleaning. Other filters

Other filters

Filters media that have been used in the past as bacteria proof  Filters media that have been used in the past as bacteria proof  filters include asbestos pads, ceramic filters and kieelguhr candles.

filters include asbestos pads, ceramic filters and kieelguhr candles.

Testing of filters Testing of filters

 The Bp requires that the integrity of an assembled sterilizing filter  The Bp requires that the integrity of an assembled sterilizing filter be verified before use and confirmed after use by means of a suitable be verified before use and confirmed after use by means of a suitable test.

test.

Bacteriologi

Bacteriological cal test test 

 The filter may be challenged by the passage of a diluted 24-48 hour  The filter may be challenged by the passage of a diluted 24-48 hour broth culture of Serratia marcescens. A sample of the filtrate is collected broth culture of Serratia marcescens. A sample of the filtrate is collected ase

aseptipticalcally ly and and incincubaubated ted at at 25°25°C C for for 5 5 daydays. s. ThiThis s ororganganisism m iscischoshosenen because it has a small cell size ( 0,3-0,4 πm across). It grows vigorously in because it has a small cell size ( 0,3-0,4 πm across). It grows vigorously in aerobic conditions and produces a readily detected

aerobic conditions and produces a readily detected red pigment.red pigment. Bubble pont test 

Bubble pont test 

 The bubble point of a test filter is the pressure at which the largest  The bubble point of a test filter is the pressure at which the largest pore of a watted filter is able to pass air. The pressure varies with the pore of a watted filter is able to pass air. The pressure varies with the surface tension of the liquid with which the filter is wetted. Details of  surface tension of the liquid with which the filter is wetted. Details of  bubble pressure testing are given in the relevant British Standard (BS bubble pressure testing are given in the relevant British Standard (BS 17

175252:1:196963)3). . StStererilile e memembmbrarane ne fifiltlterers s cacan n be be teteststed ed bebefofore re ususe e by by aa bu

bubbbble le prpresessusure re mmetethohod, d, ususuaualllly y dedescscriribebed d in in ththe e mamanunufafactctururerer’s’s literature.

literature.

Sterility testing Sterility testing

In

In-p-prorocescess s cocontntrorols ls arare e nonot t gegeneneraralllly y avavaiailalablble e fofor r memeththodods s of of  sterilization by filtration. It is therefore advisable to withold the issue of  sterilization by filtration. It is therefore advisable to withold the issue of  products sterilized by this method until sterility data is

products sterilized by this method until sterility data is available.available.

FILTRATION STERILIZATION

FILTRATION STERILIZATION

Ke

Kennnneteth h E. E. AvAvisis; ; LeLeon on LaLachchmaman; n; HeHerbrberert t A. A. LiLiebeberermaman. n. 19199393.. Pharmaceutical DosageForm

Pharmaceutical DosageForms:Parenteral Medication Volume 3. s:Parenteral Medication Volume 3. New York New York   The validation of 0,2 micron porosity membranes for the removal of   The validation of 0,2 micron porosity membranes for the removal of  viable organisms from liquids and geses differs significantly from other viable organisms from liquids and geses differs significantly from other sterilization procedures. In each of the sterilization processes presented sterilization procedures. In each of the sterilization processes presented earlier in this chapter, the treatment process involved the destruction of  earlier in this chapter, the treatment process involved the destruction of  th

the e mimicrcroooorgrgananisisms ms by by ththe e apapplplicicatatioion n of of a a leleththal al enenviviroronmnmenent. t. InIn st

stererililizizatatioion n by by fifiltltraratition on ththe e ororgaganinismsms s arare e nonot t dedeststroroyeyed, d, bubut t araree se

sepapararateted d frfrom om ththe e flfluiuid d by by papassssagage e of of ththe e flfluiuid d ththrorougugh h a a popororousus mem

membrabrane. ne. The The natnature ure of of filfiltratratiotion n proprocescesses ses reqrequiruires es the the concontrotrol l of of  pa

pararamemeteters rs vevery ry didiffffererenent t frfrom om ththosose e usused ed in in ototheher r ststererililizizatatioionn procedures in order to reproducibly effect sterilization in this manner. The procedures in order to reproducibly effect sterilization in this manner. The major parameters of interest are fluid bioburden, filter integrity, and filter major parameters of interest are fluid bioburden, filter integrity, and filter po

temperature, pressure, viscosity, filter area solvent type , PH, and other temperature, pressure, viscosity, filter area solvent type , PH, and other fluid attributes.

fluid attributes.

Validation program outline Validation program outline

  T

  The he vavalilidadatition on of of fifiltlter er ststererililizizatatioion n hahas s bebeen en ththe e susubjbjecect t of of  considerable disagreement within the parental industry. Several attempts considerable disagreement within the parental industry. Several attempts to prepare an industry standard for the validation of membrane filtration to prepare an industry standard for the validation of membrane filtration have failed because of a lack of consensus on the finer points of the have failed because of a lack of consensus on the finer points of the integrity testing and microbial challenge methodology. Despite the lack of  integrity testing and microbial challenge methodology. Despite the lack of  ag

agrereememenent t on on sosome me dedetatailils, s, ththerere e is is a a dedegrgree ee of of acacceceptptanance ce of of ththee general concepts of

general concepts of filter sterilization validationfilter sterilization validation.. 1.

1. FilFilter/ter/FluiFluid d CompCompatibiatibilitylity   T

  The he fifirsrst t ststep ep in in ththe e vavalilidadatition on of of a a nenew w fifiltltraratition on sysyststem em is is ththee establishment of compatibility between the filter and the fluid (product). establishment of compatibility between the filter and the fluid (product).   T

  Thihis s is is gegenenerralally ly a a tatask sk shsharared ed by by ththe e fifiltlter er mamanunufafactctururer er anand d ththee parenteral manufacturer. The filter manufacturer will provide information parenteral manufacturer. The filter manufacturer will provide information regarding the likely effect of the fluid on the filter, as well as identifying regarding the likely effect of the fluid on the filter, as well as identifying the components of the filtration system that will come into contact with the components of the filtration system that will come into contact with the fluid. The parenteral firm will closely examine the process fluid for the the fluid. The parenteral firm will closely examine the process fluid for the presence of filter components and any deleterious effect on its process presence of filter components and any deleterious effect on its process materials. For existing systems, where the filter has been

materials. For existing systems, where the filter has been utilized for someutilized for some years, this step is largely ignored because of the availability of historical years, this step is largely ignored because of the availability of historical data. However, significant change in filter or process fluid should prompt a data. However, significant change in filter or process fluid should prompt a re-evaluation of compatibility. The downside risk associated with a

re-evaluation of compatibility. The downside risk associated with a changechange in materials is such that many firms will continue to utilized older filter in materials is such that many firms will continue to utilized older filter medi

media a to to precpreclude compatiblude compatibiliility ty evalevaluatiuations ons requrequired to ired to emplemploy oy newernewer filtration systems.

filtration systems.

Fluid evaluation. Evaluating the effect of the filter on the process fluid Fluid evaluation. Evaluating the effect of the filter on the process fluid will usually entail some form of stability testing with

will usually entail some form of stability testing with careful assessment of careful assessment of  key product attributes. Samples for this type of testing are prepared by key product attributes. Samples for this type of testing are prepared by having the filter immersed in the process fluid for an extended period of  having the filter immersed in the process fluid for an extended period of  ti

timme e at at cocondndititioions ns (t(temempeperaratuturere, , pHpH) ) apapprproxoximimatatining g ththosose e of of ususe.e. Information and test procedures from the filter manufacturer can be used Information and test procedures from the filter manufacturer can be used to determine whether any components of the filter can be detected in the to determine whether any components of the filter can be detected in the pr

prododucuctsts. . WhWhen en cocondnducuctiting ng ththesese e tytype pe of of ststududieies. s. It It is is imimpoportrtanant t toto remember that in many filtration systems there

remember that in many filtration systems there are additional materials inare additional materials in the cartridge and housings that are not part of the membrane proper. The the cartridge and housings that are not part of the membrane proper. The

potential for interaction of these materials with the product must be also potential for interaction of these materials with the product must be also evaluated.

evaluated.

In addition to confirming that filter materials have not been introduced In addition to confirming that filter materials have not been introduced in

into to ththe e prprododucuct t at at ununacacceceptptabable le lelevevelsls, , cacarerefuful l ananalalysysis is of of ththe e flfluiuidd pro

producduct t mumust st be be conconducductedted. . TheThere re are are numnumeroerous us refrefereerencences s to to filfilterterss selec

selectiveltively y remoremoving ving indiindividuvidual al compcomponentonents s of of a a formformulatulation ion [46][46]. . TheThe po

potetentntiaial l to to chchanange ge in in ththe e flfluiuid, d, as as a a coconsnseqequeuencnce, e, of of cocontntacact t wiwithth materials in the filter and its support systems, is assessed through the materials in the filter and its support systems, is assessed through the completion of accelerated and long-term stability studies that will confirm completion of accelerated and long-term stability studies that will confirm th

the e cocommpapatitibibilility ty of of ththe e chchososen en sysyststemem. . AAssssiiststanance ce frfrom om ththe e fifiltlterer manufacturer in the identification and quantification of filtration system manufacturer in the identification and quantification of filtration system materials and advice in the selection of the most appropriate filtration materials and advice in the selection of the most appropriate filtration m

medediium um fofor r a a pparartiticucullar ar flfluiuidd, , iis s eessssenenttiial al to to ththe e ssucuccecesss s oof f ananyy compatibil

compatibility ity determinatidetermination on effort.effort.

Filter evaluation. Inparellel with the evaluation of likely effects on the Filter evaluation. Inparellel with the evaluation of likely effects on the process materials as a consequence of contact with the filtration system, process materials as a consequence of contact with the filtration system, a

a cacarerefuful l rereviview ew of of ththe e cocompmpononenent t of of ththe e fifiltltraratition on sysyststem em cacan n bebe beneficial. Changes in the appearance and properties of the filter system beneficial. Changes in the appearance and properties of the filter system c

coommppeenneerriitts s mmaay y bbe e eeasasiilly y ddeteteecctteed d aannd d lleaead d tto o a a mmoorre e rraappiidd determination of potential incompatibilities. The filter suppilier should be determination of potential incompatibilities. The filter suppilier should be able to provide a comprehensive set of test criteria that can be utilized to able to provide a comprehensive set of test criteria that can be utilized to confirm materiam suitability. Common method for this evaluation include confirm materiam suitability. Common method for this evaluation include change in weight , chang in integrity test result, change in appearance, change in weight , chang in integrity test result, change in appearance, and so on . while the absence of a significant change in the filtration and so on . while the absence of a significant change in the filtration system is no aclear indication of compatibility with the prosess fluid, the system is no aclear indication of compatibility with the prosess fluid, the detection of measurable changes in the filter system materials should be detection of measurable changes in the filter system materials should be a warning of

a warning of potential problemspotential problems.. 2.

2. FiFiltlter Iner Intetegrgritityy   Th

  The e conconfirfirmatmatioion n of of filfilter ter intintegregrity ity is is reqrequiruired ed for for eveevery ry stesterirililizinzingg filtration. Parenteral firms will test their sterilizing filtration systems before filtration. Parenteral firms will test their sterilizing filtration systems before (in

(in manmany y cascases) es) and and aftafter er use use to to conconfirfirm m the the filfilterter’s ’s intintegregrityity. . TesTestintingg before filtration is sometimes omitted for

before filtration is sometimes omitted for smaller systems where the costssmaller systems where the costs associated with refiltration, in the case

associated with refiltration, in the case of integrity failure post-filtration, isof integrity failure post-filtration, is acceptable low. The confirmation of filter integrity after completion of the acceptable low. The confirmation of filter integrity after completion of the sterilizing filtration is universal. For the most part, in-plat integrity test sterilizing filtration is universal. For the most part, in-plat integrity test ut

utililizize e phphysysicical al memeththodods s ththat at hahave ve bebeen en cocorrrrelelatated ed to to ththe e mimicrcrobobiaiall ret

retentention ion capcapabiabililitities es of of the the filfilterter. . ComCommomon n intintegregrity ity testest t inincluclude de thethe bubble-point test, diffusive flow test, and pressure hold test, each of which bubble-point test, diffusive flow test, and pressure hold test, each of which rely on the physical measurements taken in the parenteral facility. The rely on the physical measurements taken in the parenteral facility. The phy

which establishes microbial retention for filters exhibiting similar physical which establishes microbial retention for filters exhibiting similar physical test results.

test results. Bubb

Bubble-Pole-Point int TestTest. . The The most commonlmost commonly y utilutilized ized memmembrane integribrane integrityty test is the bubble-point test. In this case, the filter is fully wetted with the test is the bubble-point test. In this case, the filter is fully wetted with the test fluid (WFI and various alcohols are the standard fluids), the supply of  test fluid (WFI and various alcohols are the standard fluids), the supply of  liquid is stopped, a low-pressure gas stream is applied to the upstream liquid is stopped, a low-pressure gas stream is applied to the upstream side of the filter membrane, and the pressure is slowly increased. The side of the filter membrane, and the pressure is slowly increased. The pressure at which the largest pore in the filter is opened to the passage of  pressure at which the largest pore in the filter is opened to the passage of  the gas is the bubble point. The determination of the bubble point is the gas is the bubble point. The determination of the bubble point is some

somewhat what operoperator ator dependependent. dent. SeverSeveral al filtfilter er suppsupplier lier have have intrintroduceoducedd automated test aparatur that can provide greater reliability in the test automated test aparatur that can provide greater reliability in the test result, but their use is not widespread because of the high cost of the result, but their use is not widespread because of the high cost of the au

autotomamateted d ununitit. . ThThe e bububbbble le popoinint t is is dedepependndenent t upupon on ththe e sisize ze of of ththee largest pore in the filter and the viscosity and surface tension of the fluid. largest pore in the filter and the viscosity and surface tension of the fluid. Filter users must establish the appropriate bubble point for their process Filter users must establish the appropriate bubble point for their process fluids; such values may be either higher or lower than those utilized by fluids; such values may be either higher or lower than those utilized by the filter manufacturers to control their production.

the filter manufacturers to control their production. For

Forwarward d FlFlow ow TesTest. t. The The forforwarward d floflow w testest t is is utiutililized zed for for all sizes of all sizes of  filtration systems but is most useful in larger systems (those which utilize filtration systems but is most useful in larger systems (those which utilize cartridge filters) where the large volume of the system may make the cartridge filters) where the large volume of the system may make the accurate determination of the bubble point more difficult. In the forward accurate determination of the bubble point more difficult. In the forward flow test, a fixed pressure and volume of gas is applied to the upstream flow test, a fixed pressure and volume of gas is applied to the upstream surface of a wetted filter. The volume of gas that diffuses through the surface of a wetted filter. The volume of gas that diffuses through the filter in a given period of time is proportional to the size of the

filter in a given period of time is proportional to the size of the pores in thepores in the me

membmbraranene. . As As ththe e popore re sisize ze inincrcreaeaseses, s, ththe e amamouount nt of of gagas s flflow ow wiwillll increase. When conducted at a pressure approximately 80% of the bubble increase. When conducted at a pressure approximately 80% of the bubble point, the forward flow test can confirm filter integrity and differentiate point, the forward flow test can confirm filter integrity and differentiate between filters of different pore sizes.

between filters of different pore sizes. The specific values obtained for thisThe specific values obtained for this test are related to the test fluid utilized. Filter manufacturers will have test are related to the test fluid utilized. Filter manufacturers will have available data on WFI and other common solvents, but filter users must available data on WFI and other common solvents, but filter users must establish acceptable values unique to their process fluids.

establish acceptable values unique to their process fluids.

Pressure Hold Test. The pressure hold test is closely related to the Pressure Hold Test. The pressure hold test is closely related to the forward flow test and relies on a similar concept. As stated earlier, the forward flow test and relies on a similar concept. As stated earlier, the diffusive flow across a wetted filter is proportional to the size of the pores diffusive flow across a wetted filter is proportional to the size of the pores in the membrane surface. In this test, the supply of gas to the system is in the membrane surface. In this test, the supply of gas to the system is sto

stoppepped d and and the the drodrop p in in upsupstrtream eam prepressussure re caucaused sed by by difdiffusfusive ive flofloww across the membrane can be related to the pore size of

across the membrane can be related to the pore size of filter. As with eachfilter. As with each of the advantage of

of the advantage of not requiring a down-stream connection to the systemnot requiring a down-stream connection to the system ma

makinking g it it momost st suisuitabtable le for for popost-st-stesterirililizatzatioion n inintegtegritrity y testestinting, g, whewherere maintenance of sterility is

3.

3. MicMicrorobiabial Chall Challenlenge Tesge Testintingg   Th

  The e perperforformamance nce of of a a mimicrocrobibial al chachallllengenge e to to a a filfiltratratition on syssystem istem is definitive proof of the filter’s ability to eliminate microorganism in the definitive proof of the filter’s ability to eliminate microorganism in the process fluid. Filter manufacturers utilize specialized test apparatus and process fluid. Filter manufacturers utilize specialized test apparatus and conditions to confirm the microbial retention capabilities of their filters in conditions to confirm the microbial retention capabilities of their filters in a variety of challenge conditions. The result of the microbial challenge a variety of challenge conditions. The result of the microbial challenge studies are closely related to the physical parameters associated with studies are closely related to the physical parameters associated with int

integregrity ity testestinting, g, thetherebreby y allallowowing ing filfilter ter ususers ers to to empemploloy y the the phyphysicsicalal methods to establish the microbial retention of their filtration system.

methods to establish the microbial retention of their filtration system.

Laboratory Challenge. A number of filter users place their confidence in Laboratory Challenge. A number of filter users place their confidence in the completion of laboratory challenges (generally performed solely by the completion of laboratory challenges (generally performed solely by the filter supplier), in conjuction with physical

the filter supplier), in conjuction with physical integrity tests performed onintegrity tests performed on plan

plant t filtfiltratiration on systsystems, to ems, to estabestablislish h the the accepacceptabiltability ity of of theitheir r filtfiltratirationon sys

systemtems. s. TheThese se firfirms ms belbelievieve e thathat t the the corcorrelrelatiation on betbetweeween n mimicrocrobibialal retention in the laboratory and physical methods in the parenteral plant is retention in the laboratory and physical methods in the parenteral plant is sufficient to established the sterility of their

sufficient to established the sterility of their effluent materials.effluent materials.

Process System Challenge. Other firms believe that the unique aspects Process System Challenge. Other firms believe that the unique aspects o

of f tthhe e pprroodduuccttiioon n eennvviirroonnmmeennt t pprreecclluudde e tthhe e uusse e oof f pphhyyssiiccaall measurements alone to establish the retention capabilities of the

measurements alone to establish the retention capabilities of the filtrationfiltration system. These firm adapt the laboratory challenge methods of the filter system. These firm adapt the laboratory challenge methods of the filter ma

manunufafactctururer er anand d ememplploy oy mimicrcrobobiaial l chchalallelengnges es in in a a prprododucuctition on sisizeze filtration system with

filtration system with appropriate modificatioappropriate modifications ns to facilitate to facilitate samplingsampling..

Process Fluid in Laboratory. A third approach is the hybridization of the Process Fluid in Laboratory. A third approach is the hybridization of the pre

previoviouslusly y desdescricribed bed metmethodhods. s. In In thithis s prproceocedurdure, e, the the proprocescess s flufluid id isis microbial

microbially challenged in ly challenged in a laboratory setting under conditions that a laboratory setting under conditions that closelyclosely approximate those in use in the operating area. In this instance, the use of  approximate those in use in the operating area. In this instance, the use of  the process fluid rather than the saline system commonly utilized by the the process fluid rather than the saline system commonly utilized by the filter manufacturer is intended to stimulate the production situation more filter manufacturer is intended to stimulate the production situation more closely.

closely.

Each of these techniques has advantages and disadvantages relative Each of these techniques has advantages and disadvantages relative to the other methods. The inability of the industry to establish a single to the other methods. The inability of the industry to establish a single app

approaroach ch to to fifiltelter r stesterirililizatzation ion valvalidaidatiotion n has has to to a a larlarge ge extextent ent faifailedled because of the very strong opinios of proponents of one method or an because of the very strong opinios of proponents of one method or an other.

other.

Microbial Challenge Procedure. The confirmation of the filter integrity Microbial Challenge Procedure. The confirmation of the filter integrity via microbial challenge is a task of some complexity. Details of the test via microbial challenge is a task of some complexity. Details of the test procedure vary according to the pore size of the membrane (0,45; 0,2; or procedure vary according to the pore size of the membrane (0,45; 0,2; or 0,1 micrometer) and the test organism (

0,1 micrometer) and the test organism (S. marcesans, P. diminuta, and S. marcesans, P. diminuta, and   A.Laidawii,

differences in test procedure from one filter manufacturer to another are differences in test procedure from one filter manufacturer to another are subtle but significant. Various adaptations have been made by different subtle but significant. Various adaptations have been made by different in

inveveststigigatatorors s to to chchalallelengnge e fifiltlterers s or or didiffffererenent t sisizezes, s, in in gagas s phphasasee applications, over extended time periods, etc. While integrity tests appear applications, over extended time periods, etc. While integrity tests appear to

to be be dedefifininititive ve prproooof f of of ththe e fifiltlterer’s ’s ababililitity y to to reretatain in ororgaganinismsms, s, ththee sp

spececiaialilizezed d cicircrcumumststananceces s of of ththe e tetest st memeththodods s arare e susuch ch ththat at didirerectct confirmation of filter integrity in the parenteral plant appears impossible. confirmation of filter integrity in the parenteral plant appears impossible. Essentially, one place faith in one’s supplier that the filters being supplied Essentially, one place faith in one’s supplier that the filters being supplied will yield a sterile effluent as confirmed by the integrity test with the will yield a sterile effluent as confirmed by the integrity test with the process fluid.

process fluid. 4. Filter

4. Filter SterilizatiSterilizationon

A Satisfactory means for sterilization of the filter medium and its A Satisfactory means for sterilization of the filter medium and its housing must be identified and validated. For

housing must be identified and validated. For larger fluid systems, this willlarger fluid systems, this will likely entail sterilization-in-place as described earlier in this chapter, for likely entail sterilization-in-place as described earlier in this chapter, for sm

smalalleler r fifiltltraratition on sysyststemems, s, ststererililizizatatioion n in in a a ststeaeam m auautotoclclavave e is is ththee pr

prefefererrered d memeththodod. . In In sosome me ininststananceces, s, ththe e fifiltltraratition on mmedediuium m or or ititss supportive materials cannot withstand steam sterilization and the filter supportive materials cannot withstand steam sterilization and the filter must be sterilized using an alternative procedure. Regardless of the type must be sterilized using an alternative procedure. Regardless of the type of

of stersteriliilizatiozation n procprocedure utilizeedure utilized d , , conficonfirmatrmation ion of of the the filtfilter’s er’s inteintegritgrityy af

afteter r ststererililizizatatioion n mumust st be be peperfrforormemed. d. ThThis is is is ususuaualllly y acaccocompmplilishsheded through the performance of an integrity test. In applications such as tank through the performance of an integrity test. In applications such as tank or sterilizer vents, it is recommended that filter-life studies be conducted or sterilizer vents, it is recommended that filter-life studies be conducted to establish the maximum number of cycles to which the filter can be to establish the maximum number of cycles to which the filter can be subjected without risk of failure.

subjected without risk of failure. A

A fufurrthther er coconnsisidederratatiioon n iin n ththe e ststereriilliizazatitioon n oof f fifilltterers s iis s tthehe per

perforformanmance ce of of the the iniinititial al comcompatpatibiibilility ty stustudidies es ususing ing fifiltrltratiation on medmediaia sterilized in accord with normal practices. Conducting the compatibility sterilized in accord with normal practices. Conducting the compatibility st

stududieies s in in ththis is mmanannener r elelimimininatates es ththe e popotetentntiaial l fofor r didiffffererenenceces s inin compatibility brought about by the stresses crated during the sterilization compatibility brought about by the stresses crated during the sterilization procedure.

procedure. 5.

5. Bioburden DeterminationBioburden Determination

A further confirmation of the suitability of its membrane filtration A further confirmation of the suitability of its membrane filtration pro

procedcedurures, es, the the fifiltelter r ususer er wiwill ll oftoften en ininstastate te a a biobioburburden den momoninitortoringing program for its process fluids. This program will entail the sampling of the program for its process fluids. This program will entail the sampling of the fluid prior to passage through the final filter. Maximum benefit are gained fluid prior to passage through the final filter. Maximum benefit are gained from a bioburden sampling plan if the plan addresses seasonal variations, from a bioburden sampling plan if the plan addresses seasonal variations, alternative suppliers, multiple lots, time period from manufacturing, etc, alternative suppliers, multiple lots, time period from manufacturing, etc, to accommodate the range of conditions likely to impact the microbial to accommodate the range of conditions likely to impact the microbial content. The testing plan should include count and identification of the content. The testing plan should include count and identification of the organism(s) found. Additional benefits can be gained if additional data on organism(s) found. Additional benefits can be gained if additional data on

th

the e prprococesess s is is gagaththerered ed at at ththe e sasame me titime me as as ththe e sasammplple e is is tatakeken.n. Information regarding the batch size and filtration area can be utilized in Information regarding the batch size and filtration area can be utilized in conjunction with the microbial count to determine the maximum number conjunction with the microbial count to determine the maximum number of

of orgorganianisms presesms presentented d to to the the filfilter ter and and allallow ow the the detdetermerminainatiotion n of of aa theoretical SAL.

theoretical SAL. 6. Air and

6. Air and vent filter applicationsvent filter applications

Membrane filters in the 0,2 micrometer range are widely used for Membrane filters in the 0,2 micrometer range are widely used for the filtration of compressed gases and as vent filters. The validation of  the filtration of compressed gases and as vent filters. The validation of  fil

filterters s utiutililized in zed in thethese se appapplilicatcationions s reqrequiruires es somsome e adjadjustustmement nt in thein the methods employed.

methods employed.

IIssssueues s wwiith th rereggarard d to to fifillteterr-g-gas as cocommpapattiibibilliity ty arare e vivirrtutualalllyy nonexistent for most common gases. The filter manufacturer should be nonexistent for most common gases. The filter manufacturer should be able to provide information on more exotic gases. Filter manufacturers able to provide information on more exotic gases. Filter manufacturers have also adapted the microbial challenge test to gas filtration systems, have also adapted the microbial challenge test to gas filtration systems, using an aerosol challenge. The particulars of this test have been well using an aerosol challenge. The particulars of this test have been well def

definined ed by by the the fifiltelter r mamanufnufactactureurers rs and and virvirtuatualllly y all all useusers rs relrely y on on thethe manufacturer’s data in validating their

manufacturer’s data in validating their systems.systems. Con

Confirfirmatmatioion n of of filfilter ter intintegregrity ity for for gas gas phaphase se filfiltratratiotion n syssystemtemss in

intrtrododucuces es alalevevel el of of cocompmplelexixity ty to to ththe e ususerer. . AlAll l of of ththe e cocommmmon on fifiltlterer int

integregrity test metity test methodhods s reqrequiuire a re a wetwetted filtted filter surfaer surface, whice, which must bech must be dried before the filter can be utilized for filtration of the gas. As the vast dried before the filter can be utilized for filtration of the gas. As the vast majority of air and vent filters are hydrophobic, a

majority of air and vent filters are hydrophobic, a suitable solvent must besuitable solvent must be ut

utililizized ed ththat at wiwill ll enenteter r ththe e poporeres s of of ththe e memembmbraranene. . ThThe e adaddiditition on of of  upstream and downstream connection points to the system to allow for upstream and downstream connection points to the system to allow for testing and solvent removal is required.

testing and solvent removal is required. St

Stererililizizatatioion n of of memembmbrarane ne fifiltlterers s fofor r gagas s phphasase e apapplplicicatatioion n isis per

perforformed med usiusing ng metmethodhods s sisimimilar lar to to thothose se ememploployed yed for for liliquiquid-pd-phashasee filters. The earlier section of this chapter addressing sterilization-in-place filters. The earlier section of this chapter addressing sterilization-in-place addresses the major issues

addresses the major issues fully.fully. 7. Filter manufacturer Vs.

7. Filter manufacturer Vs. Filter user ResponsibilitiFilter user Responsibilitieses

Clearly the filter supplier. Plays a far greater role in the validation Clearly the filter supplier. Plays a far greater role in the validation for filtr

for filtratioation n than does any sterilthan does any sterilizer manufizer manufacturacturer. The pharmaceer. The pharmaceuticuticalal firm is in essential partnership with its filter suppliers for the maintenance firm is in essential partnership with its filter suppliers for the maintenance of its sterility assurance. The

of its sterility assurance. The control followed by the control followed by the filter manufacturer infilter manufacturer in the conduct of its business are of critical importance to the validation of  the conduct of its business are of critical importance to the validation of  the

the filtfiltratioration n stersteriliilizatiozation n procprocess. ess. For For this this reasreason, on, filtfilter er manumanufactufacturersrers utilize many of the GMP concepts and validation method evidenced in the utilize many of the GMP concepts and validation method evidenced in the ph

phararmamaceceututicical al ininduduststryry. . OpOpen en cocommmmununicicatatioion n bebetwtweeeen n ththe e fifiltlterer manufacturer and filter user is essential to

STERILIZATION BY FILTRATION

STERILIZATION BY FILTRATION

USP 30 volume I USP 30 volume I

Fi

Filtltraratition on ththrorougugh h mimicrcrobobiaial l reretetentntivive e mamateteririalals s is is frfreqequeuentntlyly employed for the sterilization of heat labile solutions by physical removal employed for the sterilization of heat labile solutions by physical removal of the contained microorganisms. A filter assembly generally consist of a of the contained microorganisms. A filter assembly generally consist of a po

pororous us mamatrtrix ix sesealaled ed or or clclamampeped d ininto to an an imimpepermrmeaeablble e hohoususining. g. ThThee effectiveness of a filter medium or substrate depends upon the pore size effectiveness of a filter medium or substrate depends upon the pore size of the porous material and may depend upon adsorption of bacteria on or of the porous material and may depend upon adsorption of bacteria on or in the filter matrix or upon a sieving mechanism. There is some evidence in the filter matrix or upon a sieving mechanism. There is some evidence to

to inindidicacate te ththat at sisievevining g is is ththe e momore re imimpoportrtanant t cocompmpononenent t of of ththee mechanism. Fiber-shedding filters, particularly those containing asbestos, mechanism. Fiber-shedding filters, particularly those containing asbestos, are to be avoided unless no alternative filtration procedures are possible. are to be avoided unless no alternative filtration procedures are possible. Where a fiber-shedding filter is required, it is obligatory that the process Where a fiber-shedding filter is required, it is obligatory that the process include a non fiber-shedding filter introduced downstream or subsequent include a non fiber-shedding filter introduced downstream or subsequent to the initial filtration step.

to the initial filtration step. Fi

Filtlter er raratitingng- - ththe e popore re sisizezes s of of fifiltlter er memembmbraranenes s arare e rarateted d by by aa nominal rating that reflects the capability of the filter membrane to retain nominal rating that reflects the capability of the filter membrane to retain mi

micrcroooorgrgananisisms ms of of sisize ze rereprpresesenenteted d bubut t spspececififieied d ststrarainins, s, nonor r byby determination of an average pore size and statement of distribution of  determination of an average pore size and statement of distribution of  sizes. Sterilizing filter membranes (those used for removing a majority of  sizes. Sterilizing filter membranes (those used for removing a majority of  con

contamtaminainatinting g mimicrocroororganganisisms) ms) are are memmembrbraneanes s capcapablable e of of retretainaininingg 100% of a culture of 10

100% of a culture of 1077 _{micrmicroorgoorganismanisms s of of a a straistrain n of of pseudpseudomoomonasnas}

diminuta (ATCC 19146) per square centimeter of membrane surface under diminuta (ATCC 19146) per square centimeter of membrane surface under a pressure of not less than 30 psi (2.0 bar). Such filter membranes are a pressure of not less than 30 psi (2.0 bar). Such filter membranes are nominally rated 0,22 µm or 0,2 µm, depending on the manufacturer’s nominally rated 0,22 µm or 0,2 µm, depending on the manufacturer’s practice.

practice. This ratinThis rating of filter memg of filter membranes is albranes is also specified for so specified for reagents orreagents or media that have to be sterilized by filtration (see treatment of isopropyl media that have to be sterilized by filtration (see treatment of isopropyl Myristate under oils and oily solutions or ointments and creams in the Myristate under oils and oily solutions or ointments and creams in the chapt

chapter er stersteriliility ty testtests s (71)(71)). ). BacteBacterial filter rial filter membmembranes (also ranes (also knowknown n asas analytical filter membranes), which are capable of retaining only larger analytical filter membranes), which are capable of retaining only larger microorganisms, are labeled with a nominal rating 0,45 µm. no single microorganisms, are labeled with a nominal rating 0,45 µm. no single

authoritative method for rating 0,45 µm filters has been specified, and authoritative method for rating 0,45 µm filters has been specified, and this rating are depends on conventional practice among manufacturers; this rating are depends on conventional practice among manufacturers; 0,4

0,45 5 µm µm filfilterters s are are capcapablable e of of retretainaining ing parparticticulular ar culculturtures es of of serserratratiaia marcescens (ATCC 14756) or ps. Diminuta. Test pressures used vary from marcescens (ATCC 14756) or ps. Diminuta. Test pressures used vary from low (5 psi, 0.33 bar for serratia, or 0,5 psi, o.34 bar for ps. diminuta) to low (5 psi, 0.33 bar for serratia, or 0,5 psi, o.34 bar for ps. diminuta) to hi

high gh (5(50 0 pspsi, i, 3.3.4 4 babar)r). . ThThey ey arare e spspececififieied d fofor r ststererililitity y teteststining g (s(seeee membrane filtration in the section test for sterility of the product to be membrane filtration in the section test for sterility of the product to be examined under sterility tests) where less exhaustive microbial retention examined under sterility tests) where less exhaustive microbial retention is required. There is a small microorganisms). Filter membranes with a is required. There is a small microorganisms). Filter membranes with a very low nominal rating may be tested with a culture of Acholeplasma very low nominal rating may be tested with a culture of Acholeplasma laidlawii or other strain of mycoplasma, at a pressure of 7 psi (0,7 bar) laidlawii or other strain of mycoplasma, at a pressure of 7 psi (0,7 bar) and be nominally rated 0,1 µm. the nominal ratings based on microbial and be nominally rated 0,1 µm. the nominal ratings based on microbial retention properties differ when rating is done by other means, e.g., by retention properties differ when rating is done by other means, e.g., by rretetenenttiion on of of llatatex ex ssphphereres es oof f vavarriiouous s didiamameteterers. s. IIt t iis s tthe he uuseserr’s’s responsibility to select a filter of correct rating for the particular purpose, responsibility to select a filter of correct rating for the particular purpose, depending on the nature of the product to be filtered. It is generally not depending on the nature of the product to be filtered. It is generally not ffeeaassiibblle e tto o rreeppeeaat t tthhe e tteesst t oof f ffiillttrraattiioon n ccaappaacciitty y iin n tthhe e uusseerr’’ss establishm

establishment. Microbial challenge tests are ent. Microbial challenge tests are preferably performed under apreferably performed under a manufacturer’s conditi

manufacturer’s conditions on each ons on each lot of manufactured filter membranes.lot of manufactured filter membranes.  The user must determine whether filtration parameters employed in  The user must determine whether filtration parameters employed in manu

manufactufacturing ring wilwill l signsignificificantlantly y inflinfluence uence micrmicrobiaobial l retenretention tion effiefficiencciency.y. Some of the other important concerns in the validation of the filtration Some of the other important concerns in the validation of the filtration process include product compatibility, sorption of drug, preservative or process include product compatibility, sorption of drug, preservative or other additives, and initial effluent endotoxin content.

other additives, and initial effluent endotoxin content.

Since the effectiveness of the filtration process is also influenced by Since the effectiveness of the filtration process is also influenced by th

the e mimicrcrobobiaial l buburdrden en of of ththe e sosolulutition on to to be be fifiltlterereded, , dedetetermrmininining g ththee microbiol

microbiological quality of solutions prior to ogical quality of solutions prior to filtration is an important aspectfiltration is an important aspect of the validation of the filtration process, in addition to establishing the of the validation of the filtration process, in addition to establishing the other parameters of the filtration procedure, such as pressures, flow rates, other parameters of the filtration procedure, such as pressures, flow rates, and filter unit characteristics. Hence, another method of describing and filter unit characteristics. Hence, another method of describing filter-re

retataininining g cacapapabibilility ty is is ththe e ususe e of of ththe e lolog g rereduductctioion n vavalulue e (L(LRVRV). ). FoForr in