Kapangidwe ka mankhwala a HPMC

Hydroxypropyl Methylcellulose (HPMC)ndi ether ya cellulose yosakhala ionic, yomwe ndi chinthu chosinthidwa ndi mankhwala chomwe chimapangidwa ndi momwe cellulose yachilengedwe imagwirira ntchito ndi propylene oxide ndi methyl chloride pambuyo pa alkalization. HPMC ili ndi kukhazikika kwabwino kwa thupi ndi mankhwala ndipo imagwiritsidwa ntchito kwambiri mu mankhwala, zipangizo zomangira, chakudya, zodzoladzola ndi zina. Makhalidwe ake a mankhwala ndi awa:

1. Makhalidwe a kapangidwe ka maselo

Chigoba chachikulu cha HPMC chimachokera ku cellulose yachilengedwe, yomwe imapangidwa ndi mayunitsi a shuga olumikizidwa ndi ma β-1,4-glycosidic bonds kuti apange unyolo wa macromolecular. Kuyambitsidwa kwa magulu a hydroxypropyl ndi methoxy kumalowa m'malo mwa magulu a hydroxyl (-OH) pa unyolo wa maselo a cellulose, motero kumapatsa mawonekedwe apadera. Mlingo uwu wa kusintha (monga, mlingo wa kusintha kwa magulu a methoxy ndi hydroxypropyl) uli ndi mphamvu yofunika kwambiri pa kusungunuka, mawonekedwe a gel ndi kukhazikika kwa HPMC.

2. Kusungunuka

HPMC ndi polima wamba wosungunuka m'madzi wosasungunuka ndi ioni womwe ungatuluke mofulumira m'madzi ozizira ndikupanga yankho lowonekera kapena lowala la colloidal. Komabe, m'madzi otentha, HPMC siisungunuke mosavuta ndipo imapanga gel pa kutentha kwambiri. Kapangidwe ka gel iyi yosinthika ndi imodzi mwazofunikira kwambiri zakuthupi ndi zamakemikolo a HPMC. Kuwonjezera pa madzi, HPMC imathanso kusungunuka m'zinthu zina zachilengedwe, monga solvent yosakanikirana ya ethanol ndi madzi, dimethylformamide, ndi zina zotero.

3. Kukhazikika kwa kutentha ndi kusungunuka kwa madzi

HPMC ili ndi kukhazikika kwabwino kwa kutentha. Pamene kutentha kukukwera, maunyolo a mamolekyu a HPMC mu yankho lamadzi adzakumana ndi kupha madzi kuti apange kapangidwe ka netiweki ya magawo atatu, ndipo kusintha kuchokera ku yankho kupita ku gel kudzachitika. Kutentha kwa gelation kumadalira kuchuluka ndi kulemera kwa mamolekyu a zinthu zosinthira. Kawirikawiri, HPMC yokhala ndi hydroxypropyl yambiri imakhala ndi kutentha kwakukulu kwa gelation, pomwe HPMC yokhala ndi methoxy yambiri imakhala ndi kutentha kochepa kwa gelation.

Gelation imatha kusinthidwa, ndipo gel imasungunukanso kukhala madzi ikazizira. Kapangidwe kapadera ka thermogel kameneka kamapangitsa HPMC kugwiritsidwa ntchito nthawi zambiri ngati chinthu chotulutsa mankhwala komanso chogwiritsidwa ntchito mumakampani opanga zida zomangira kuti iwonjezere magwiridwe antchito a matope omangira.

4. Kukhazikika kwa pH

HPMC imasunga kukhazikika bwino mu pH ya 3 ~ 11. Kukhazikika kwakukulu kwa pH kumeneku kumalola kuti igwiritsidwe ntchito m'malo osiyanasiyana popanda kuwonongeka kapena mvula. Pamene pH ili yotsika kuposa 3 kapena kupitirira 11, yankholo likhoza kuwonongeka kapena kusungunuka chifukwa cha kuchuluka kwa ma hydrogen ions kapena ma hydroxide ions ambiri, zomwe zimapangitsa kuti magwiridwe antchito achepe.

5. Kusinthika kwa Mankhwala

Chifukwa cha kukhalapo kwa magulu ena a hydroxyl osasinthidwa mu molekyulu ya HPMC, imasungabe ntchito inayake ya mankhwala ndipo imatha kuchita zotsatirazi:

Kuchitapo kanthu kwa esterification: Pazifukwa zoyenera, HPMC imatha kuchitapo kanthu ndi acyl chloride, anhydride, ndi zina zotero kuti ipange ma ester;

Kuchitapo kanthu kwa etherification: Magulu otsala a hydroxyl amatha kupitiliza kuchitapo kanthu ndi zinthu zotenthetsera (monga ma epoxide) kuti asinthe kwambiri kuchuluka kwa kusintha ndi magwiridwe antchito a HPMC;

Kuchitapo kanthu kwa okosijeni: Pakakhala ma oxidant amphamvu (monga potaziyamu permanganate, sodium hypochlorite), unyolo wa mamolekyu a HPMC ukhoza kusweka, zomwe zimapangitsa kuti kukhuthala kuchepe;

Hydrolysis reaction: Pogwiritsa ntchito ma asidi amphamvu kapena maziko amphamvu, ma hydroxypropyl ndi ma methoxy side chains amatha kusungunuka, zomwe zimapangitsa kusintha kwa kapangidwe ka mamolekyulu ndi kuchepa kwa magwiridwe antchito.

Kawirikawiri, pansi pa kugwiritsidwa ntchito bwino, mphamvu za mankhwala a HPMC zimakhala zokhazikika.

6. Kuwonongeka kwa zinthu zachilengedwe

HPMC imachokera ku cellulose yachilengedwe, kotero imatha kusungunuka kukhala shuga waung'ono m'malo enaake achilengedwe (monga pogwiritsa ntchito tizilombo toyambitsa matenda), kenako n’kusungunuka kukhala carbon dioxide ndi madzi. Kuwonongeka kwabwino kumeneku kumapangitsa HPMC kukwaniritsa zofunikira za zipangizo zosawononga chilengedwe.

7. Kugwirizana ndi zinthu zina

Monga polima yopanda ionic, HPMC imagwirizana bwino ndi zowonjezera zosiyanasiyana za ionic kapena zopanda ionic (monga ma polima ena, ma surfactants, zokhuthala, ndi zina zotero). Makamaka mu dongosolo lopangira, imatha kugwira ntchito ndi zosakaniza zosiyanasiyana za mankhwala, zakudya, utoto, ndi zina zotero popanda mvula kapena kugawa.

Kukhazikika kwa HPMC m'malo okhala ndi ma electrolyte ambiri kudzakhudzidwa, ndipo mchere wambiri wosapangidwa ungapangitse kuti kukhuthala kwa yankho kuchepe kapena kutha.

8. Kukana kwa ma enzyme

Poyerekeza ndi cellulose yachilengedwe,HPMCyawonjezera kukana kwa cellulase chifukwa cha kusintha kwa magulu ena a hydroxyl, ndipo siiwonongeka mosavuta ndi ma enzymes wamba. Izi zimapatsa mwayi woti mankhwala atuluke mochedwa m'mimba.

Hydroxypropyl methylcellulose (HPMC) ndi chinthu chachilengedwe chosinthidwa ndi mankhwala chomwe chimasungunuka bwino m'madzi, kutentha kwambiri, pH yokhazikika, kukhazikika kwa mankhwala komanso kuwonongeka kwa zinthu. Chifukwa cha kapangidwe kake kapadera komanso mphamvu zake zamankhwala, HPMC imagwiritsidwa ntchito kwambiri m'magawo azachipatala, zipangizo zomangira, zokutira, chakudya, zodzoladzola, ndi zina zotero, makamaka m'mapangidwe omwe amafunikira kukhuthala, kutulutsidwa kolamulidwa, kupanga filimu, kuyimitsidwa, emulsification ndi ntchito zina.