Self Nano-emulsifying Drug Delivery System to Enhance Solubility and Dissolution of Candesartan Cilexetil

Aim: Self nano-emulsifying drug delivery system (SNEDDS) of candesartan cilexetil was explored to enhance its oral bioavailability. SNEDDS has tremendous potential in enhancing oral bioavailability of poorly aqueous soluble therapeutic agents. SNEDDS are pre-concentrate mixture of oil, surfactant and co-surfactant produces nanoemulsion after oral administration due to mild agitation produced by gastro motility within the size range of 20-200nm. Methodology: The formulations were developed by selecting capmul MCM^®, triacetin^® and caprylic acid® under the oil phase based on solubility of drug; cremophore RH40^®, brij35^® under surfactants category and transcutol P under co-surfactant on basis of their emulsification property. Optimum concentrations were choosen from the Terinary phase diagrams and evaluated for their properties. Results: From the results of ternary diagrams 16 formulations were selected (A1, A2, A3, A4, B1, B2, C1, C2, C3, C4, D1, D2, E1, E2, F1, F2) and subjected to characterization studies. Best formulations were subjected to particle size analysis and in vitro release studies. Among selected formulations, A1 and C1 have shown high in vitro drug release profiles with less selfemulsification time having grade A dispersibility without any precipitation and phase separation. Discussion: Concentration of surfactant helps in reducing the size of the particle when compared to the co-surfactant concentration. Enhanced dissolution of candesartan cilexitil may be attributed to the spontaneous formation of nanoemulsion in vitro with a decreased particle size that leads to the increased surface area leaving the drug candesartan as finely dispersed particles in dissolution media. Conclusion: Formulation C1 consists of triacetin oil 30% w/w, cremophore RH 40 6%w/w and transcutol P 64%w/w showed best emulsification characteristics like 99% percent transmittance, with increased dissolution profile (98%) than pure drug (45%) with nano range goblet size (165.9nm).