DEVELOPMENT AND INVESTIGATION OF TIMOLOL MALEATE AND TRAVOPROST COMBINATION NIOSOMAL IN SITU GELLING SYSTEM FOR THE TREATMENT OF GLAUCOMA

The aim of the present investigation was to develop a combination of timolol maleate and travoprost niosomal in situ gelling system for the treatment of glaucoma. Niosomes were prepared by thin film hydration technique using rotary flash evaporator. A 32 factorial design was utilized to study the effect of the molar ratio of Span 60 (X1) and cholesterol (X2) on vesicle size, drug entrapment efficiency and in vitro release study. On the basis of vesicle size, maximum entrapment efficiency and in vitro release of drug, best formulations were selected for the preparation of niosomal in situ gel (Drop). On the basis of gelling time and viscosity, optimized ratio of the polymers was selected for the desired preparation. Selected niosomal batches were dispersed in carbopol 940 and HPMC K4M polymer solution (combination IF6) to form in situ gel niosomal formulations (Drop). The gelling time of the niosomal in situ gel (NIF1) was found to be the best (+++) and the viscosity was found to be 1190 cP. Zeta potential, average size analysis, polydispersibility index value was found to be -45.1 mV, 256.5 nm, 0.228 respectively. In vitro drug release was found to be within the range of 50.23 ± 0.54 to 60.23 ± 0.33% over the period of 6 h. IOP lowering activity of best formulation (NIF1) showed more significant and sustained effect than the marketed eye drops. Best formulation (NIF1) was found to be stable, sterile, non irritant and isotonic. Hence niosomal in situ gelling combination system may have the potential of bringing better application than the conventional ocular therapy with improved ocular bioavailability and increased patient compliance.