Abstract

SOLUBILITY ENHANCEMENT OF BCS CLASS II ANTIHYPERTENSIVE DRUG USING SOLID SELF EMULSIFICATION TECHNIQUE

Shwetha Krishnamurthy*, Srinivasan Bharath, Varadharajan Madhavan

ABSTRACT

Self emulsifying drug delivery systems (SEDDS) are isotropic mixtures of oil, surfactant and co-surfactant which are generally present in the form of liquid or semi-solid. Solid- SEDDS (S-SEDDS) are solid forms of liquid SEDDS converted into solid by suitable means. Candesartan cilexetil a Biopharmaceutical classification system (BCS) Class II drug is a nonpeptide angiotensin II type 1(AT1) receptor antagonist used in the treatment of hypertension. It has an oral bioavailability of 15% because to its low solubility across the physiological pH. The main objective of the study was to formulate SSEDDS of candesartan cilexetil by adsorption process using a solid inert carrier. Various formulations were prepared at concentrations of oleic acid 20%, 40%, Poly ethylene glycol (PEG) 400 and Tween 80 at 1:2 and 1:4 ratios, and liquid SEDDS to Microcrystalline cellulose (MCC) at 1:1 and 1:2 ratios. The results of micromeritic properties showed that S- SEDDS had good powder flow properties. A visual test was carried out to asses self emulsification of S-SEDDS which showed spontaneous emulsification and there was no sign of phase separation. A fine milky emulsion was formed within 2 min. The formulations containing 1:4 surfactant to cosurfactant ratio showed faster drug release when compared to 1:2 ratio. The effect of adsorbent in drug release characteristics of Liquid SEDDS was assessed and its concentration in the formulation was optimized. Thus S-SEDDS of candesartan showed better solubility enhancement and dissolution rate in contrast to pure drug formulation which would further prove to enhance the oral bioavailability.

Keywords: Candesartan cilexetil, Solid self emulsifying drug delivery system, solid carriers, solubility enhancement.