A comparative study of modified starches in direct compression of a poorly water soluble drug (hydrochlorothiazide)

The direct compression properties of four modified starches in hydrochlorothiazide (HCTZ) tablets were studied. The starches were obtained locally from common plant sources and were modified through physicochemical treatment. Each modified starch was used as the only filler-binder-disintegrant in the formulation of hydrochlorothiazide tablets containing 25 mg of the drug. The tablets were produced by the direct compression technology. Sta-Rx 1500, a directly compressible starch, was used as basis for comparison. Evaluated tablet properties included weight and drug content uniformity, hardness and friability as well as disintegration time and dissolution profile. The modified starches exhibited species specificity in terms of the tablet properties. The weight, drug content and disintegration time for all batches of tablets were within acceptable limits. Proper ranking of the starches on the basis of specific tablet properties was used to highlight their differences.