A study on Hydrotrope corn starch gelled as a carrier for topical drug delivery 

By Sayyed Nazim, M.H.G Dehghan, Siraj Shaikh, Pravin Gomase, Mohammed Zameeruddin and Majaz Quazi 

ABSTRACT

Starches form an important class of gel forming material of natural origin; hydrotropic salts not only induce swelling and gelatinisation of starch at reduced temperatures but at fairly high concentrations increase the solubility of poorly soluble drugs in water. The present research work mainly concern with to evaluate the potential of hydrotropic gelled corn starch as a suitable vehicle for topical drug delivery and to determine the effect of change in starch/ hydrotropic salt concentration on Rheology of the gel with Rofecoxibs invitro drug release study from the formulated gel. In this study the potential of hydrotrope-gelled starch as a carrier for topical delivery of model drug (Rofecoxib )is seen. Various batches of hydrotrope gelled starches were prepared using 32 factorial designs. Corn starch along with hydrotropic salts sodium salicylate and sodium benzoate were used. The formulations were evaluated for various parameters such as physical appearance, homogeneity, pH, drug content uniformity, and rheological properties. In- vitro drug release of model drug from the formulations was studied using Keshary-Chein type diffusion cell. It was observed that hydrotropic salt sodium salicylate induced better gelling than sodium benzoate. The viscosity increased with an increase in the concentration of polymer. Higher concentration of salts yielded more viscous gels. The gels prepared using sodium benzoate showed higher viscosity. In-vitro release data shows that hydrotrope-gelled containing 1% Rofecoxib in 10%w/w corn starch and 15%w/w sodium salicylate (W8SCD) showed highest percent drug release 23.53% in 6hrs. These formulations showed much higher release when compared to some marketed formulations whose percent release were between the ranges of 15.81% to 4.77% in 6hrs. The release of Rofecoxib from hydrotrope-starch gel formulations was influenced by initial drug concentration in the vehicle, starch concentration and to a lesser extent the hydrotrope concentration. Thus different release rates may be achieved by controlling these factors.

Keywords: Corn starch, Gel, spreatability, Transdermal drug delivery, Hydrotropes 

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