Reološka karakterizacija i ispitivanje stabilnosti formulacija liposomi-u-kitozanskom gelu

master's thesis

• Title (english): Rheological characterization and storage stability of liposomes embedded into chitocan hydrogel
• Author: Ivana Frankol
• Mentor: Zora Rukavina (mentor)
• Committee member: Zora Rukavina (predsjednik povjerenstva)
• Committee member: Željka Vanić (član povjerenstva)
• Committee member: Emerik Galić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmaceutical technology); Zagreb
• Defense date and country: 2024-04-24, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Različite vrste liposoma s azitromicinom (AZT): konvencionalni liposomi (CL), deformabilni liposomi (DL), propilenglikol liposomi (PGL) i kationski liposomi (CATL) uklopljeni su u hidrogel na bazi kitozana s ciljem postizanja prikladne viskoznosti za topikalnu primjenu na kožu. Dobivene formulacije liposomi-u-gelu (CL-HG, DL-HG, PGL-HG, CATL-HG) reološki su okarakterizirane rotacijskim i oscilacijskim testovima te im je ispitan pH. Dodatkom AZT-liposoma ili AZT-otopine (kontrola) u kitozanski gel (30 %, m/m) dolazi do blagog smanjenja viskoznosti gela, no formulacije i dalje zadržavaju viskoznost prikladnu za dermalnu primjenu te strukturu i ponašanje viskoelastičnih krutina (gelova). Nadalje, sve ispitivane formulacije liposomi-u-gelu pokazale su linearnu viskoelastičnu regiju (LVR), iz čega proizlazi da se ispitani uzorci neposredno nakon primjene mogu smatrati dobro dispergiranima i stabilnima. Reološka mjerenja su ponovljena nakon 30 dana skladištenja pri 4 °C, pri čemu je utvrđeno da formulacije liposomi-u-gelu nakon skladištenja pokazuju manju viskoznost u odnosu na viskoznost formulacije neposredno nakon izrade, ali uz zadržavanje viskoelastičnog ponašanja svojstvenog gelovima. Dodatak liposoma i AZT-otopine u izvorni gel uzrokovao je blago povišenje pH formulacija. Iako je nakon 30 dana skladištenja zabilježen statistički značajan pad pH svih formulacija, izmjerene vrijednosti i dalje su bile prikladne za dermalnu primjenu. Većina formulacija liposomi-u-gelu pokazala je zadovoljavajuću razinu stabilnosti tijekom 30-dnevnog skladištenja. Izuzetak je formulacija DL-HG koja je tijekom skladištenja toliko primijenila konzistenciju da nije bilo moguće provesti mjerenja nakon 30 dana, što upućuje na postojanje inkompatibilnosti između DL i kitozanskog gela, koju je potrebno potvrditi daljnjim ispitivanjima.

Abstract (english)

Different types of azithromycin (AZT)-loaded liposomes: conventional liposomes (CL), deformable liposomes (DL), propylene glycol liposomes (PGL), and cationic liposomes (CATL) were embedded into a chitosan-based hydrogel to achieve suitable viscosity for topical application onto the skin. The obtained liposome-in-gel formulations (CL-HG, DL-HG, PGL-HG, CATL-HG) were rheologically characterized by rotational and oscillatory tests, and their pH was examined. Although the addition of AZT-liposomes or AZT-solution (control) into chitosan gel (30%, w/w) caused a slight decrease in gel viscosity, the formulations still retained viscosity suitable for dermal application and the structure and behavior of viscoelastic solids (gels). Furthermore, all tested liposome-in-gel formulations showed a linear viscoelastic region (LVR), indicating that the tested samples could be considered well-dispersed and stable immediately after preparation. Rheological measurements were repeated after 30 days of storage at 4 °C, revealing that liposome-in-gel formulations exhibited lower viscosity after storage compared to the viscosity of formulations immediately after preparation, while retaining viscoelastic behavior characteristic for gels. Liposomes and AZT-solution embedded into the chitosan gel caused a slight increase in the pH of the gel. Although a statistically significant decrease in pH was observed for all formulations after 30 days of storage, the measured values were still suitable for dermal application. Majority of liposome-in-gel formulations showed satisfactory stability during the 30-day storage. An exception was the DL-HG formulation, which underwent such a change in consistency during storage that measurements after 30 days were not possible, suggesting certain incompatibility between DL and chitosan gel, which needs to be confirmed by further research.

• Keywords: liposomi-u-gelu; kitozan; azitromicin; reologija; stabilnost
• Keywords (english): liposomes-in-gel; azithromycin; chitosan; rheology; stability
• Language: croatian
• URN:NBN: urn:nbn:hr:163:084093
• Study programme: Title: Pharmacy - integrated undergraduate and graduate - university study; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: sveučilišni magistar farmacije (sveučilišni magistar farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-05-23 12:57:50