THE EFFECT OF CONVERTING LIQUID VALSARTAN SNEDDS INTO SOLID SNEDDS USING DIFFERENT SOLID CARRIERS ON ITS PERFORMANCE
Valsartan is an angiotensin converting enzyme inhibitor which is poorly soluble in water, which leads to low oral bioavailability (19-25%). For this reason, the study target was to formulate self nanoemulsifying drug delivery system of valsartan to enhance dissolution rate which would further achieve a better oral bioavailability. Valsartan solubility was checked in various vehicles in order to construct ternary phase diagram as a useful tool to evaluate the nanoemulsion domain. The formulations were prepared using (capryol 90 - tween 80 - polyethylene glycol 400) as (oil – surfactant –co surfactant) respectively. The prepared formulations were tested for nanoemulsifying properties and the resultant nanoemulsions were evaluated for the ability of self emulsification, viscosity, robustness to dilution and drug content. The optimized liquid formulations were adsorbed onto a solid carrier yielding powder with suitable flowability properties ready for encapsulation. The dissolution profiles of solid formulations filled into hard gelatin capsules were established and compared with liquid formulations and commercial formulation to make sure that the self-emulsifying properties didn`t change following conversion. The solid intermediates illustrated a challenging extent and rate of drug dissolution in an artificial dissolution medium as liquid which prove that the self-emulsifying properties of the system were unaffected following conversion using t-test: two sample assuming equal variances. Also, the dissolution extent and rate for solid intermediates were significantly higher than commercial tablet formulation. The results demonstrate the potential use of this system as a perfect technique for improving solubility, dissolution, and as a result the bioavailability