Formulation and evaluation of hydrochlorothiazide liquisolid tablets

ABSTRACT

The technique of liquisolid preparations was used to formulate hydrochlorothiazide, a model drug, in tablet form. Drug solution in peg200 was blended with different common tablet excipients such as Avicel, Aerosil, Calcium phosphate, Magnesium oxide, and Magnesium carbonate. The drug admixtures were directly compressed into tablets. The dissolution rates of the liquisolid tablets were determined according to USP basket method. The obtained dissolution profiles were compared to that of a reference tablet, made by simple trituration of drug powder with avicel, and a commercial product. The results showed that, generally, liquisolid tablets present a significantly higher dissolution rate. A dissolution profiles were obtained implying that formulations are true liquisolids. However, precipitation and consequently retention of the drug in the cavities of porous recipients were noticed upon the contact of drug solution with dissolution medium. This retention could be minimized by using a dilute drug solution or a crystallization inhibitor viz. PVP. The dissolution profile of the liquisolid tablets was found to be greatly affected not only by the type of excipient[s] but, also, the mixing order of the excipients