Abstract
Objective: Aim of study was to formulate chitosan-gelatin hydrogels containing ascorbic acid, an antioxidant, with/without polyelectrolyte-complex.
Material and Method: Effect of formation polyelectrolyte-complex, gelatin concentration (10-20%) and chitosan:gelatin ratio(1:1, 1:2, 2:1w/w) on the rheological properties, in-vitro release, encapsulation efficiency of hydrogels were investigated. Dissolution rates were also compared using area under dissolution curve (AUC), mean dissolution time (MDT), mean residence time (MRT). Also, the potential for topical use of the hydrogel was evaluated by examining the 24-and 72-hours cytotoxic and proliferative effects on L929 cell line using MTT test.
Result and Discussion: Polyelectrolyte complex formation led to improved drug release and increased viscosity. Cell viability of the free and drug-loaded polyelectrolyte-hydrogels was over 70% at the end of the 72h in all formulations (except formulations with chitosan:gelatin ratio of 1:2w/w) showed that ascorbic acid and hydrogels did not cause cellular toxicity and could be used safely. It has been demonstrated that the gelatin ratio should be at most 50%, and excess gelatin reduces cell viability. F6-coded-polyelectrolyte-hydrogel (20% gelatin; 2:1 chitosan:gelatin w/w) was ideal formulation as it led to best sustained drug release with high MDT and AUC values, and cell viability >80%. In conclusion, polyelectrolyte-complex formation is more superior, and chitosan:gelatin ratio and gelatin concentration can be manipulated to obtain the desired properties.