Brookfield DV3T Rheometer Manual do Utilizador descarregar pdf (Página 90)

Brookeld Engineering Labs., Inc. Page 90 Manual No. M13-2100

AnExampleoftheCassonModelatWork

Beforereleasinganewoverthecountergel,a

pharmaceuticalcompanyneedstolearnhow

itwillbehavewhichitisbeingusedbythe

endconsumer.Theyperformafullviscosity

proleandapplytheCassonmodel.Fromthe

results,showninFigureVII-4,theylearnthat

theirointmenthasahigheryieldstress,τ

,and

lowerplasticviscosity,

h,thantheyoriginally

intended.Asaresultitisdifcultordispensefromitscontainer(duetothehighyieldstress)

anditdoesnotholditshapeverywell(duetothelowplasticviscosity),makingitdifcultto

applyasmallamounttotheaffectedareaoftheskin.Basedonthisdata,formulatorsareable

tomodifytheingredientsaccordingly.Onceaformulationisestablished,multi-pointtestsand

theCassonmodelareperformedasaQCtooltocheckbatchesbeforeandafterprocessing.

Pharmaceutical Gel

Plastic Viscosity (

h) = 329.8 cP

Yield Stress (τ

) = 325.8 dynes/cm

1 2 ... 85 86 87 88 89 90 91 92 93 94 95 ... 124 125

Sem comentários

Brookfield DV3T Rheometer Manual do Utilizador Página 90