Preparation and characterization of thermosensitive in situ gel containing berberine bovine serum albumin nanoparticles for ophthalmic drug delivery

Objective To prepare a thermosensitive in situ gel containing berberine bovine serum albumin nanoparticles(Ber-BSANPs-Gel) for ophthalmic drug delivery and preliminarily investigate its physicochemical properties.Methods Poloxamer 407(F127) and Poloxamer 188(F68) were used as gel matrix,and gelatinization temperature was applied as a target to optimize the prescription.The Ber-BSA-NPs were prepared by desolvation method,and the in situ gel system of Ber-BSA-NPs-Gel was obtained by cold-dissolving method.NDJ—1 Viscometer was used to determine the viscosity of the system,simulated tear fluid(STF) was applied as release medium,and ultraviolet spectrophotometry was employed as the assay method to inspect its in vitro release characteristics.Results After optimization,the gel prescription was finally confirmed as 26% F127 and 4% F68.The optimized formulation was freely flowing liquid at 30.9 ℃ and converted to a firm gel at 34.2 ℃ after STF diluted.The in vitro study indicated that Ber-BSA-NPs-Gel possessed a superior sustained-release effect.Conclusion The in situ thermosensitve gel system meets the requirements for ophthalmic application and shows the great potential in ocular application.