Biopharmaceutic and pharmacokinetic studies following the oral administration of sodium salicylate in oily and aqueous vehicles to rabbit

The pharmacokinetic parameters, i.e. peak concentration (cmax); peak time (tmax); area under the curve (AUC); elimination rate constant (k); absorption rate constant (ka); Drug clearance (clt), and the volume of distribution (vd)(vd) of sodium salicylate administered in fractionated coconut oil (FCO) have been compared with that from an aqueous and glycerin vehicles using a three-way crossover study in 12 rabbits. The results of the study show that all of the pharmacokinetic parameters tested differ significantly when administered in oily rather than aqueous or glycerin vehicles. No statistically significant difference was found between any of the above mentioned parameters when comparison was made between aqueous and glycerin formulations. The results indicate that sodium salicylate is absorbed at a lower rate but to a greater extent from oily formulation. Possible reasons for these differences are discussed and is suggested, therefore, that the oily formulation might be used as a sustained release preparation.