Kweyiphi i-pH i-HPMC enyibilikayo

IHydroxypropyl methylcellulose (HPMC)yipolima esetyenziswa ngokuqhelekileyo kumayeza, kwizinto zokuthambisa, nakwiimveliso zokutya. Ukunyibilika kwayo kuxhomekeke kwizinto ezahlukeneyo, kuquka i-pH. Ngokubanzi, i-HPMC iyanyibilika kuzo zombini iimeko ze-asidi kunye ne-alkaline, kodwa ukunyibilika kwayo kunokwahluka ngokusekelwe kwiqondo lokuthatha indawo (DS) kunye nobunzima bemolekyuli (MW) yepolymer.

Kwiimeko ezineasidi, i-HPMC idla ngokubonisa ukunyibilika okulungileyo ngenxa ye-protonation yamaqela ayo e-hydroxyl, ephucula ukuchithwa kwayo kunye nokusasazeka. I-solubility ye-HPMC ithande ukunyuka njengoko i-pH isihla ngaphantsi kwe-pKa yayo, emalunga ne-3.5-4.5 ngokuxhomekeke kwiqondo lokutshintshwa.

Ngokuchaseneyo, kwiimeko ze-alkaline, i-HPMC inokunyibilika, ngakumbi kumaxabiso aphezulu e-pH. Kwi-alkaline pH, ukuchithwa kwamaqela e-hydroxyl kwenzeka, okukhokelela ekwandeni kwe-solubility ngokusebenzisa i-hydrogen bonding kunye neemolekyuli zamanzi.

Nangona kunjalo, kubalulekile ukuqaphela ukuba eyona pH apho i-HPMC inyibilika khona inokwahluka ngokusekwe kwibakala elithile le-HPMC, idigri yayo yokuthatha indawo, kunye nobunzima bayo bemolekyuli. Ngokuqhelekileyo, amabakala e-HPMC aneqondo eliphezulu lokuthatha indawo kunye neentsimbi ezisezantsi zeemolekyuli zibonisa ukunyibilika okungcono kumaxabiso aphantsi e-pH.

Kwimixube yamayeza,HPMCisetyenziswa rhoqo njengefilimu yangaphambili, i-thickener, okanye i-stabilizer. Iimpawu zayo zokunyibilika zibalulekile ekulawuleni iiprofayili zokukhutshwa kweziyobisi, i-viscosity yokwakheka, kunye nokuzinza kwe-emulsions okanye ukumiswa.

ngelixa i-HPMC ngokuqhelekileyo i-soluble phezu koluhlu olubanzi lwe-pH, ukuziphatha kwayo kwe-solubility inokulungiswa kakuhle ngokulungelelanisa i-pH yesisombululo kunye nokukhetha ibakala elifanelekileyo le-HPMC ngokusekelwe kwisicelo esifunwayo.