Development and optimization of film forming non-pressurized liquid bandage for wound healing by Box-Behnken statistical design

The goal of the current investigation was to develop a non-pressurized liquid bandage to promote the healing of wounds by using silver sulfadiazine. A three-factor three level box-behnken statistical design was employed to optimize the drug-loaded liquid bandage. Film-forming liquid bandage was developed by using ethyl-cellulose, dibutyl sebacate, and glycerol. For optimization, ethyl cellulose, dibutyl sebacate, and isopropyl myristate were taken as independent variables while tensile strength, water vapor absorption value, and drying time were taken as dependent variables. The film-forming liquid bandage was evaluated for various parameters like tensile strength, water vapor absorption value, drying time, viscosity, pH, in-vitro drug release studies, in-vivo wound healing studies, and stability studies. The optimized formulation was found with the tensile strength of 68.24 ± 0.24 MPa, water vapor absorption value of 2.00 ± 0.25 %, drying time of 1.75 ± 0.14 min, viscosity of 60 ± 0.5 cPs, pH of 6.0 ± 0.5 and good physicochemical properties with satisfactory film-forming ability. The in-vitro study shows that the release of test formulations was better than the marketed formulation. After 6 h of study, the liquid bandage and marketed formulation showed 41.02 % and 29.32 % of drug release respectively. Significant results were obtained for the in-vivo wound healing studies. Upon comparison with the control group (2.61 mm) and marketed formulation (1.44 mm), rats treated with the optimized formulation exhibited a noticeable improvement in wound contraction (0.8 mm). The liquid bandage after three months of stability testing was found to be stable with optimum. The film-forming liquid bandage was found to be an effective alternative to conventional topical preparations as it develops a thin polymeric layer on the wound and the skin around it and improves comfort for the patient by protecting the wound from external factors and physical harm.