SOLUBILITY ENHANCEMENT OF CANDESARTAN CILEXETIL BY SELF EMULSIFYING DRUG DELIVERY SYSTEMS

The present research work was aimed at the enhancement of solubility of Candesartan by Self Emulsifying Drug Delivery Systems (SEDDS). Candesartan is a BCS class II drug having low aqueous solubility and high permeability; hence its bioavailability is solubility rate limited. The saturated solubility of Candesartan in various oils and surfactants was determined. The excipients were screened and selected showing maximum solubility and compatibility for Candesartan. SEDDS formulations of Candesartan were developed using different Oils, Surfactants and Co-Surfactant combinations. Pseudoternary phase diagrams were constructed using Triplot V 4.1.2  software and applying Pseudoternary phase diagrams, microemulsification area was evaluated. Formulations were prepared based on phase diagrams using various proportions of oil, surfactants and co-surfactants. The formulations were screened visually for stability and phase separation. Seven formulations were selected for further evaluations like effect of dilution, freeze-thawing, emulsion droplet size and zeta potential. Among the seven formulations three were optimized and filled in hard gelatin capsules. The in-vitro dissolution studies of the SEDDS formulation were performed and the dissolution rate of SEDDS was compared with plain Candesartan (API). The results indicated that the solubility and dissolution rate of Candesartan was significantly higher than that of plain drug (API).  The results of the present studies demonstrate that SEDDS can be used as a potential means for improving solubility, dissolution and bioavailability of Candesartan.