Lapho i-pH i-HPMC encibilikayo

I-Hydroxypropyl methylcellulose (HPMC)iyi-polymer evame ukusetshenziswa kwezemithi, izimonyo, nemikhiqizo yokudla. Ukunyibilika kwayo kuncike ezintweni ezihlukahlukene, kuhlanganise ne-pH. Ngokuvamile, i-HPMC iyancibilika kuzo zombili izimo ezine-asidi ne-alkaline, kodwa ukunyibilika kwayo kungahluka ngokuya ngezinga lokushintsha (DS) nesisindo samangqamuzana (MW) se-polymer.

Ezimweni ezine-acidic, i-HPMC ngokuvamile ibonisa ukuncibilika okuhle ngenxa ye-protonation yamaqembu ayo e-hydroxyl, okuthuthukisa ukugeleza kwayo kanye nokuhlakazeka. Ukunyibilika kwe-HPMC kuvame ukukhuphuka njengoba i-pH yehla ngaphansi kwe-pKa yayo, ecishe ibe ngu-3.5–4.5 kuye ngezinga lokushintsha.

Ngokuphambene, ezimeni ze-alkaline, i-HPMC ingaphinda incibilike, ikakhulukazi ngamavelu e-pH aphezulu. Ku-alkaline pH, ukuwohloka kwamaqembu e-hydroxyl kwenzeka, okuholela ekwandeni kokuncibilika ngokuhlangana kwe-hydrogen nama-molecule amanzi.

Kodwa-ke, kubalulekile ukuqaphela ukuthi i-pH eqondile lapho i-HPMC inyibilika khona ingahluka ngokuya ngebanga elithile le-HPMC, izinga layo lokushintsha, kanye nesisindo sayo samangqamuzana. Ngokuvamile, amamaki e-HPMC anamadigri aphezulu okushintsha nezisindo zamangqamuzana aphansi abonisa ukunyibilika okungcono ngamavelu e-pH aphansi.

Ekwakhekeni kwemithi,I-HPMCivame ukusetshenziswa njengefilimu yangaphambili, i-thickener, noma i-stabilizer. Izici zayo zokuncibilika zibalulekile ekulawuleni amaphrofayili okukhishwa kwezidakamizwa, i-viscosity of formulations, nokuzinza kwama-emulsion noma ukumiswa.

kuyilapho i-HPMC ivame ukuncibilika ngebanga elibanzi le-pH, ukuziphatha kwayo kokuncibilika kungalungiswa kahle ngokulungisa i-pH yesixazululo nokukhetha ibanga elifanele le-HPMC ngokusekelwe kuhlelo olufunekayo.