I-Hydroxypropyl Methylcellulose (HPMC) iyi-cellulose derivative esetshenziswa kakhulu enezinhlobo eziningi zezicelo, njengemithi, ukudla, izinto zokwakha kanye nezimonyo. I-HPMC iyi-polymer engeyona i-ionic, eyenziwe kancane, engasebenzi kahle enokuncibilika kwamanzi okuhle kakhulu, ukuqina, ukunamathela kanye nezakhiwo zokwakha ifilimu.
Isakhiwo kanye nezakhiwo ze-HPMC
I-HPMC iyi-cellulose eguquliwe ekhiqizwa yi-cellulose ephendulayo nge-methyl chloride kanye ne-propylene oxide. Isakhiwo sayo sama-molecule siqukethe kokubili izinto ezithatha indawo ye-methyl kanye ne-hydroxypropyl, ezinikeza i-HPMC izakhiwo zomzimba nezamakhemikhali ezihlukile, njengokuncibilika okuhle kakhulu, ukuvikelwa kwe-colloid kanye nezakhiwo zokwakha ifilimu. I-HPMC ingahlukaniswa ngezincazelo eziningi ngokuya ngezincazelo ezahlukene, futhi incazelo ngayinye inokuncibilika okuhlukile kanye nokusetshenziswa emanzini.
Ukuncibilika kwe-HPMC emanzini
Indlela yokuncibilikisa
I-HPMC ixhumana nama-molecule amanzi ngokusebenzisa izibopho ze-hydrogen ukuze yakhe isisombululo. Inqubo yayo yokuncibilika ifaka phakathi ama-molecule amanzi angena kancane kancane phakathi kwamaketanga e-molecular e-HPMC, abhubhise ukuhlangana kwayo, ukuze amaketanga e-polymer asakazeke emanzini ukuze akhe isisombululo esifanayo. Ukuncibilika kwe-HPMC kuhlobene eduze nesisindo sayo sama-molecule, uhlobo lwesithasiselo kanye nezinga lokushintshana (DS). Ngokuvamile, lapho izinga lokushintshana kwesithasiselo liphezulu, kulapho ukuncibilika kwe-HPMC emanzini kuphakeme khona.
Umphumela wokushisa ekuncibilikeni
Izinga lokushisa lingenye yezinto ezibalulekile ezithinta ukuncibilika kwe-HPMC. Ukuncibilika kwe-HPMC emanzini kubonisa izici ezahlukene njengoba izinga lokushisa lishintsha:
Izinga lokushisa lokuncibilika: I-HPMC kunzima ukuyincibilikisa emanzini abandayo (ngokuvamile ingaphansi kuka-40°C), kodwa ingancibilika ngokushesha uma ishiswa ifike ku-60°C noma ngaphezulu. Ku-HPMC ene-viscosity ephansi, izinga lokushisa lamanzi elingaba ngu-60°C ngokuvamile liyizinga lokushisa elifanele lokuncibilika. Ku-HPMC ene-viscosity ephezulu, izinga lokushisa elifanele lokuncibilika lingaba phezulu ku-80°C.
Ukwakheka kwe-Gelation ngesikhathi sokupholisa: Uma isisombululo se-HPMC sishiswa kufikela ekushiseni okuthile (ngokuvamile 60-80°C) ngesikhathi sokuncibilika bese sipholiswa kancane kancane, kuzokwakhiwa ijeli yokushisa. Le jeli yokushisa iyaqina ngemva kokupholisa iye ekushiseni kwegumbi futhi ingaphinde ihlakazwe emanzini abandayo. Lesi simo sibaluleke kakhulu ekulungiseleleni izixazululo ze-HPMC ngezinjongo ezithile ezithile (njengezikhonkwane ezikhishwa njalo ngemithi).
Ukusebenza kahle kokuncibilika: Ngokuvamile, amazinga okushisa aphezulu angasheshisa inqubo yokuncibilika kwe-HPMC. Kodwa-ke, izinga lokushisa eliphakeme kakhulu lingaholela ekuwohlokeni kwe-polymer noma ukwehla kwe-viscosity yokuncibilika. Ngakho-ke, ekusebenzeni kwangempela, izinga lokushisa lokuncibilika elifanele kufanele likhethwe njengoba kudingeka ukuze kugwenywe ukuncibilika okungadingekile kanye noshintsho lwempahla.
Umphumela we-pH ekuncibilikeni
Njenge-polymer engeyona i-ionic, ukuncibilika kwe-HPMC emanzini akuthinteki ngqo yinani le-pH lesisombululo. Kodwa-ke, izimo ze-pH ezibucayi (njengezindawo ezinamandla ze-acidic noma ze-alkaline) zingathinta izici zokuncibilika kwe-HPMC:
Izimo ze-asidi: Ngaphansi kwezimo ze-asidi enamandla (pH < 3), ezinye izibopho zamakhemikhali ze-HPMC (njengezibopho ze-ether) zingabhujiswa yi-acidic medium, ngaleyo ndlela zithinte ukuncibilika kwayo kanye nokuhlakazeka kwayo. Kodwa-ke, ebangeni le-acid elijwayelekile elibuthakathaka (pH 3-6), i-HPMC isengancibilika kahle. Izimo ze-alkaline: Ngaphansi kwezimo ze-alkaline enamandla (pH > 11), i-HPMC ingase yonakale, okuvame ukubangelwa ukusabela kwe-hydrolysis kwe-hydroxypropyl chain. Ngaphansi kwezimo ze-alkaline ezibuthakathaka (pH 7-9), ukuncibilika kwe-HPMC ngokuvamile akuthinteki kakhulu.
Indlela yokuncibilikisa ye-HPMC
Ukuze kuncibilikiswe ngempumelelo i-HPMC, izindlela ezilandelayo zivame ukusetshenziswa:
Indlela yokuhlakaza amanzi abandayo: Faka kancane kancane i-HPMC powder emanzini abandayo ngenkathi uvuselela ukuze uyihlakaze ngokulinganayo. Le ndlela ingavimbela i-HPMC ukuthi ihlangane ngqo emanzini, bese isixazululo sakha ungqimba oluvikelayo lwe-colloidal. Bese, kancane kancane uyishise ku-60-80°C ukuze uyihlakaze ngokuphelele. Le ndlela ifanelekela ukuhlakaza iningi le-HPMC.
Indlela yokusabalala kwamanzi ashisayo: Faka i-HPMC emanzini ashisayo bese uyivuselela ngokushesha ukuze uyincibilikise ngokushesha ekushiseni okuphezulu. Le ndlela ifanele i-HPMC ene-viscosity ephezulu, kodwa kufanele kunakwe ukulawula izinga lokushisa ukuze kugwenywe ukuwohloka.
Indlela yokulungiselela isixazululo ngaphambi kwesikhathi: Okokuqala, i-HPMC incibilikiswa ku-solvent ephilayo (njenge-ethanol), bese amanzi engezwa kancane kancane ukuze ayiguqule ibe yisisombululo samanzi. Le ndlela ifanelekela izimo ezikhethekile zokusetshenziswa ezinezidingo eziphezulu zokuncibilika.
Umkhuba wokuhlakazwa kwezicelo ezisebenzayo
Ezisetshenzisweni ezisebenzayo, inqubo yokuncibilikisa i-HPMC idinga ukwenziwa ngcono ngokuya ngokusetshenziswa okuthile. Isibonelo, emkhakheni wezokwelapha, ngokuvamile kuyadingeka ukwakha isixazululo se-colloidal esifanayo futhi esizinzile, futhi kudingeka ukulawula okuqinile kwezinga lokushisa kanye ne-pH ukuqinisekisa i-viscosity kanye nomsebenzi webhayoloji wesisombululo. Ezintweni zokwakha, ukuncibilika kwe-HPMC kuthinta izakhiwo zokwakha ifilimu kanye namandla okucindezela, ngakho-ke indlela engcono kakhulu yokuncibilikisa idinga ukukhethwa ihlanganiswe nezimo ezithile zemvelo.
Ukuncibilika kwe-HPMC emanzini kuthinteka yizici eziningi, ikakhulukazi izinga lokushisa kanye ne-pH. Ngokuvamile, i-HPMC incibilika ngokushesha emazingeni okushisa aphezulu (60-80°C), kodwa ingase yonakale noma ingancibiliki kakhulu ngaphansi kwezimo ze-pH ezimbi kakhulu. Ngakho-ke, ekusetshenzisweni okungokoqobo, kuyadingeka ukukhetha izinga lokushisa lokuncibilika elifanele kanye nobubanzi be-pH ngokuya ngokusetshenziswa okuthile kanye nezimo zemvelo ze-HPMC ukuqinisekisa ukuncibilika kwayo nokusebenza kwayo okuhle.
Isikhathi sokuthunyelwe: Juni-25-2024