IHydroxypropyl Methylcellulose (HPMC) sisixhobo esisetyenziswa kakhulu kwi-cellulose esineendlela ezahlukeneyo zokusetyenziswa, ezinje ngamayeza, ukutya, izinto zokwakha kunye nezinto zokuthambisa. I-HPMC yi-polymer engeyiyo ionic, eyenziweyo kancinci, engasebenzi kakuhle enokunyibilika kwamanzi, ukutyeba, ukunamathela kunye neempawu zokwenza ifilimu.
Ulwakhiwo kunye neempawu ze-HPMC
I-HPMC yi-cellulose eguquliweyo eveliswa yi-reactioning cellulose nge-methyl chloride kunye ne-propylene oxide. Ulwakhiwo lwayo lwe-molecular luqulethe zombini i-methyl kunye ne-hydroxypropyl substituents, ezinika i-HPMC iipropati zomzimba nezekhemikhali ezikhethekileyo, ezinje ngokunyibilika okugqwesileyo, ukhuseleko lwe-colloid kunye neepropati zokwenza ifilimu. I-HPMC inokwahlulwahlulwa ibe ziinkcukacha ezininzi ngokwee-substituents ezahlukeneyo, kwaye inkcazo nganye inonyibiliko olwahlukileyo kunye nokusetyenziswa emanzini.
Ukunyibilika kwe-HPMC emanzini
Indlela yokunyibilikisa
I-HPMC isebenzisana neemolekyuli zamanzi ngokusebenzisa iibhondi zehydrogen ukuze yenze isisombululo. Inkqubo yokunyibilika kwayo ibandakanya iimolekyuli zamanzi ukungena kancinci kancinci phakathi kweetsheyini zemolekyuli ze-HPMC, zitshabalalisa ukuhlangana kwayo, ukuze iitsheyini zepolymer zisasazeke emanzini ukuze zenze isisombululo esifanayo. Ukunyibilika kwe-HPMC kunxulumene ngokusondeleyo nobunzima bayo beemolekyuli, uhlobo lwe-substituent kunye neqondo lokutshintshwa (DS). Ngokubanzi, okukhona inqanaba lokutshintshwa kwe-substituent liphezulu, kokukhona ukunyibilika kwe-HPMC emanzini kuphezulu.
Impembelelo yobushushu ekunyibilikeni
Ubushushu ngomnye wemiba ebalulekileyo echaphazela ukunyibilika kwe-HPMC. Ukunyibilika kwe-HPMC emanzini kubonisa iimpawu ezahlukeneyo njengoko ubushushu butshintsha:
Uluhlu lobushushu bokunyibilika: I-HPMC kunzima ukuyinyibilikisa emanzini abandayo (ngokubanzi ingaphantsi kwama-40°C), kodwa inokunyibilika ngokukhawuleza xa ishushu ukuya kuma-60°C nangaphezulu. Kwi-HPMC ene-viscosity ephantsi, ubushushu bamanzi obumalunga nama-60°C buhlala bubushushu bokunyibilika obufanelekileyo. Kwi-HPMC ene-viscosity ephezulu, uluhlu lobushushu bokunyibilika oluphezulu lunokuba phezulu ukuya kuma-80°C.
Ukufakwa kwe-gel ngexesha lokupholisa: Xa isisombululo se-HPMC sishushu ukuya kubushushu obuthile (ngesiqhelo ngama-60-80°C) ngexesha lokunyibilika size sipholile kancinci, kuya kwenziwa ijeli yobushushu. Le jeli yobushushu iyaqina emva kokuba ipholile ukuya kubushushu begumbi kwaye ingaphinda ichitheke emanzini abandayo. Le nto ibaluleke kakhulu ekulungiseleleni izisombululo ze-HPMC ngeenjongo ezithile (ezifana neekhephusi ezikhutshwayo ngamayeza).
Ukusebenza kakuhle kokunyibilika: Ngokubanzi, amaqondo obushushu aphezulu anokuyikhawulezisa inkqubo yokunyibilika kwe-HPMC. Nangona kunjalo, amaqondo obushushu aphezulu kakhulu anokubangela ukuwohloka kwe-polymer okanye ukwehla kwe-viscosity yokunyibilika. Ke ngoko, ekusebenzeni ngokwenene, amaqondo obushushu afanelekileyo okunyibilika kufuneka akhethwe njengoko kufuneka ukuze kuthintelwe ukuwohloka okungeyomfuneko kunye notshintsho kwipropati.
Isiphumo se-pH ekunyibilikeni
Njenge-polymer engeyiyo i-ionic, ukunyibilika kwe-HPMC emanzini akuchaphazeleki ngokuthe ngqo lixabiso le-pH yesisombululo. Nangona kunjalo, iimeko ze-pH ezigqithisileyo (ezifana neendawo ezinamandla ze-acidic okanye ze-alkaline) zinokuchaphazela iimpawu zokunyibilika kwe-HPMC:
Iimeko ze-asidi: Phantsi kweemeko ze-asidi enamandla (pH < 3), ezinye iibhondi zeekhemikhali ze-HPMC (ezifana neebhondi ze-ether) zinokutshatyalaliswa yi-acidic medium, ngaloo ndlela zichaphazele ukunyibilika kwayo kunye nokusasazeka kwayo. Nangona kunjalo, kuluhlu lwe-acid ebuthathaka ngokubanzi (pH 3-6), i-HPMC isenokwahlulwahlulwa kakuhle. Iimeko ze-alkaline: Phantsi kweemeko ze-alkaline enamandla (pH > 11), i-HPMC inokonakala, okuhlala kubangelwa kukusabela kwe-hydrolysis ye-hydroxypropyl chain. Phantsi kweemeko ze-alkaline ezibuthathaka (pH 7-9), ukunyibilika kwe-HPMC kudla ngokungachaphazeleki kakhulu.
Indlela yokunyibilikisa i-HPMC
Ukuze kunyibilikiswe ngempumelelo i-HPMC, ezi ndlela zilandelayo zihlala zisetyenziswa:
Indlela yokusasazwa kwamanzi abandayo: Yongeza kancinci umgubo we-HPMC emanzini abandayo ngelixa uvuselela ukuze usasazeke ngokulinganayo. Le ndlela inokuthintela i-HPMC ukuba ingadibani ngqo emanzini, kwaye isisombululo senza umaleko okhuselayo we-colloidal. Emva koko, shushu kancinci ukuya kuma-60-80°C ukuze unyibilike ngokupheleleyo. Le ndlela ifanelekile ekunyibilikeni uninzi lwe-HPMC.
Indlela yokusasazwa kwamanzi ashushu: Yongeza i-HPMC emanzini ashushu uze uyixube ngokukhawuleza ukuze uyinyibilikise ngokukhawuleza kubushushu obuphezulu. Le ndlela ifanelekile kwi-HPMC ene-viscosity ephezulu, kodwa kufuneka kuqwalaselwe ukulawula ubushushu ukuze kuthintelwe ukuwohloka.
Indlela yokulungiselela isisombululo kwangaphambili: Okokuqala, i-HPMC iyanyibilika kwisinyibilikisi se-organic (esifana ne-ethanol), aze amanzi ongezwe kancinci kancinci ukuze ayiguqule ibe sisisombululo samanzi. Le ndlela ifanelekile kwiimeko ezikhethekileyo zokusetyenziswa ezineemfuno eziphezulu zokunyibilika.
Ukuziqhelanisa nokuchithwa kwezicelo ezisebenzayo
Kwizicelo ezisebenzayo, inkqubo yokunyibilikisa i-HPMC kufuneka iphuculwe ngokweendlela ezithile zokusetyenziswa. Umzekelo, kwicandelo lezemithi, kudla ngokuba yimfuneko ukwenza isisombululo se-colloidal esifanayo nesizinzileyo, kwaye kufuneka ulawulo oluqinileyo lobushushu kunye ne-pH ukuqinisekisa i-viscosity kunye nomsebenzi webhayoloji wesisombululo. Kwizinto zokwakha, ukunyibilikisa kwe-HPMC kuchaphazela iipropati zokwenza ifilimu kunye namandla okucinezela, ngoko ke eyona ndlela ilungileyo yokunyibilikisa kufuneka ikhethwe ngokudibeneyo neemeko ezithile zokusingqongileyo.
Ukunyibilika kwe-HPMC emanzini kuchatshazelwa zizinto ezininzi, ingakumbi ubushushu kunye ne-pH. Ngokubanzi, i-HPMC inyibilika ngokukhawuleza kumaqondo obushushu aphezulu (60-80°C), kodwa inokonakala okanye inganyibiliki kakhulu phantsi kweemeko ze-pH ezigqithisileyo. Ke ngoko, kwizicelo ezisebenzayo, kuyimfuneko ukukhetha ubushushu bokunyibilika obufanelekileyo kunye noluhlu lwe-pH ngokwendlela ethile yokusetyenziswa kunye neemeko zokusingqongileyo ze-HPMC ukuqinisekisa ukunyibilika kwayo kunye nokusebenza kwayo okuhle.
Ixesha leposi: Juni-25-2024