Chlorophyllin sodium copper salt in hydrogel formulations: spectrophotometric stability studies and in vitro release

Commercial sodium copper chlorophyllin salt (SCC) is a green pigment, antioxidant and antimutagenic agent with numerous therapeutic applications. The aim of this study was to develop, characterize and evaluate stability and in vitro release of hydrogel containing SCC and SCC-loaded liposomes, in order to enhance the stability of SCC in the carrier-containing gels compared to the conventional gels. SCC-loaded liposomes were made of soy lecithin with phosphatidylcholine content of 90%, by the thin film hydration method. Hydrogel with SCC was prepared of poly(methyl vinyl ether/maleic anhydride decadiene) crosspolymer. The final SCC concentration in liposomes and hydrogel was set to 1 × 10 –4 M. Hydrogel formulations were evaluated for physical stability during 6 months’ storage at 20 ± 2 °C. After SCC incorporation in liposomes, spectrophotometric studies have shown its improved stability compared to the aqueous environment. In vitro release study of SCC from developed liposomal suspensions and gel-type formulations was performed using direct dialysis bag technique, during 5 h. The results showed that formulation type—liposomes and hydrogel—affected the rate and amount of the released drug. SCC incorporation in liposomes gradually prolonged SCC release in comparison with SCC hydrogel and SCC solution. Poly(methyl vinyl ether/maleic anhydride decadiene) crosspolymer hydrogel formulations with and without liposomes met the requirements of physical stability based on the results of organoleptic, homogeneity, pH, viscosity and electrical conductivity tests, during 6 months.