International Journal of Drug Research and Technology

DEVELOPMENT AND EVALUATION OF SOLID SELF EMULSIFYING DRUG DELIVERY SYSTEM OF OLMESARTAN MEDOXOMIL BY USING ADSORPTION TO SOLID CARRIER TECHNIQUES

Abstract

Pallavi Patharkar and KN Tarkase

Olmesartan medoxomil (OLM) is an angiotensin II receptor blocker antihypertensive agent. It is a highly lipophilic (log p (octanol/water) 5.55), poorly water soluble drug with absolute bioavailability of 26%.The main objective of this study was to prepare a solid form of lipid based self emulsifying drug delivery system by adsorption to solid carrier technique to improve the oral bioavailability of poorly water soluble drug Olmesartan medoxomil. The solubility of OLM was determined in various vehicles like oils, surfactants and co-surfactants. Pseudoternary phase diagrams were constructed to identify the efficient selfemulsifying region. The liquid SEDDS was a system that consist of Olmesartan, Acrysol k-150, Labrasol, Transcutol P as a drug, oil, surfactant and co-surfactant. The optimized liquid SMEDDS was transformed into a free flowing powder using Avicel or Aerosil 200 as the adsorbent. Prepared SEDDS formulations were tested for microemulsifying properties and the resultant microemulsions were evaluated for robustness to dilution, assessment of efficiency of self emulsication, emulsification time, turbidity measurement, viscosity, drug content and in-vitro dissolution. The optimized SEDDS formulation further evaluated for heating cooling cycle, centrifugation studies and freeze thaw cycling, particle size distribution, zeta potential were carried out to confirm the stability of the formed SEDDS. The formulation was found to show a significant improvement in terms of the drug release with complete release of drug within 60 minutes The physical state of the drug in solid self micro emulsifying powder was revealed by Differential Scanning Calorimetric and X–ray powder diffraction studies which indicated the presence of the drug in the dissolved form in the lipid excipients..The dissolution of the drug was enhanced significantly from the SMEDDS formulation as compared to pure drug