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Design Considerations for WFI

Distillation Systems Part 4ISPEMay 26, 2016 Design Considerations for WFI Distillation Systems Part 42016-0-

26!0"#4"#1$%00#00 &no'ledge, P(arma)e*ti)al Engineering Maga+ineo Comment

Design Considerations for Water for Ine)tion .WFI/ Distillation Systems for Imroing

*ality, Proe)t Performan)e, and E3*iment ife Cy)le Cost 5ed*)tion 'as feat*red

in t(e Setemer78)toer 201 iss*e of Pharmaceutical Engineering9 maga+ine:

!(is fo*r-art series resents and dis)*sses a n*mer of ;ey re3*irements and

design, 3*ality, and engineering )onsiderations t(at (ae (ig( imortan)e in end-*ser *saility, )ost )ontrol and end-rod*)t 3*ality t(at (el manage ris;s in Water

for Ine)tion rod*)tion and ro)esses: We 'ra-* t(e WFI Distillation Systems

series 'it( art fo*r '(i)( reie's#

Imortan)e of

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gases o*t of t(e 'ater and into t(e atmos(ere t(ro*g( a gas ent: !(ese are totally

integrated in t(e still and t(*s eliminate t(e need for additional e3*iment: )ation *nit and

do'nstream of it: ig( temerat*re t(at yields (ig( F0, t(o*g( t(e )onta)t time is

s(ort, is e=e)tie against any a)terial gro't(: 8io*sly t(is adantage is di@)*lt to

get in )older systems:

n MWS is less e=e)tie at remoing total organi) )aron .!8C/, *t it )an e

remoed from feed 'ater *sing a)tiated )aron:

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!yi)al lo'do'n ratio of a distillation system is J to 1J, and 'it( softened 'ater

t(e amo*nt )an easily get * to $0J, '(i)( means an in)rease of 100J or more in

t(e ree)t 'ater amo*nt: S*)( in)reases of ree)ts )learly red*)e t(e e@)a)y of WFI

rod*)tion: In addition, an endoto?in load to t(e still may in)rease: !(is means a

(ig(er ris; of )arryoer of endoto?ins to WFI, alt(o*g( an MWS is generally erye=e)tie at remoing t(em:

Conductivity Is Not Enoug

Cond*)tiity is an e?)ellent 'ay to )ontin*o*sly monitor distillate 3*ality e)a*se it

is simle, reliale, and sensitie: o'eer, it is not s*@)ient e)a*se it indi)ates only

t(e resen)e of ioni) im*rities and is not sele)tie: If )ond*)tiity in)reases, ot(er

means are re3*ired in order to determine t(e )a*se: In addition, it does not dete)t

endoto?ins, a)terial gro't(, or !8C, all of '(i)( are imortant for WFI 3*ality and

(ae een de>ned in t(e (arma)oeias: Contin*o*s !8C monitoring in WFI

systems is normal ra)ti)e, and it )an e added to a still as 'ell: W(en t(e

*ri>)ation and monitoring systems are maintained roerly, an a))etale !8C

leel in distillate )an e rea)(ed and monitored easily: at*rally, )are m*st e ta;en

'it( maintenan)e and t(e )aliration of t(e analy+er, arti)*larly e)a*se t(e leels

are lo': Dete)ting endoto?ins on-line is not ossile 'it( )*rrent te)(nology: Ket

endoto?ins are one of t(e most )riti)al and li;ely im*rities in 'ater, so it is a to

riority to remoe t(em from WFI: n MWS is ;no'n to (ae a ery good aility to

remoe endoto?ins )ontin*o*sly: fo*r-log red*)tion )an e s(o'n ro*tinely, and

(ig(er red*)tions (ae een rea)(ed in tests: !(is toi) (as een dis)*ssed

t(oro*g(ly oer t(e years, so 'e 'ill not *t more em(asis on it (ere:

Dete)ting a)terial gro't( on-line is ossile *sing )*rrent te)(nology, *t it is not

yet a )ommon o))*rren)e: imit of determination )an also e a )on)ern: a)terial

gro't( is not dire)tly related to !8C eit(er: !(is em(asi+es t(e imortan)e of

(aing a reliale met(od for eliminating it, and t(is (as een dis)*ssed aoe: In

addition, gro't( in a still after t(e )ol*mns is (ig(ly *nli;ely e)a*se t(e lo'esttemerat*re inside t(e WFI ies is t(e same as t(e distillate o*tlet temerat*re: s

a res*lt, t(e ris; for gro't( in t(e WFI line do'nstream of t(e still is also (ig(ly

red*)ed: !(e ris; for gro't( in t(e feed-'ater lines of an MWS )an e red*)ed 'it(

a saniti+ation se3*en)e: Feed-'ater lines )an e saniti+ed if desired:

In )on)l*sion, t(ere are many fa)tors t(at a=e)t t(e design ro)ess, and t(ey need

to e eal*ated to a)(iee t(e desirale res*lt: 5is; mitigation and rod*)t 3*ality

m*st neer e )omromised, *t 'eig(ing di=erent alternaties and ossiilities

oe)tiely 'ill (el to >nd t(e most s*itale sol*tion: