Weight and content uniformity study of captopril half-tablets

Dose-related adverse effects of medications are a major problem in modern medical practice. The “correct” dose, based on drug company guidelines in package inserts, may not be correct for many patients. Tablet splitting or dividing has been an accepted practice for many years as a means of obtaining the prescribed dose of medication. As model tablets for this investigation, three brands of captopril scored tablets labeled to contain 50 mg were used. Tablets were split by hand, tablet splitter, or knife. The percentages by which each whole tablet's or half-tablet's drug content and weight difference from sample mean values were compared with Ph. Eur. specification ranges for drug weight and content. Using tablet splitter, the results showed that 13.3% and 5.83% of half-tablets fell outside of the proxy Ph. Eur specification for weight and content respectively. In case of hand and knife splitting, the percentage of half-tablets that fell outside of the proxy Ph. Eur specification increased to 62.5% (weight) and 20% (content).