Weight Variability of Scored and Unscored Split Psychotropic Drug Tablets

Abstract

The authors investigated the weight variation of split scored and unscored tablets of several dosages of three costly psychotropic drugs, using weight variation criteria based on the United States Pharmacopoeia 26 (USP) Content Uniformity of Dosage Units. Whole tablets of Paxil 20 and 40 mg, Risperdal 2 and 4 mg, and Zoloft 100 mg that had been split with a widely available device by pharmacy technicians in a managed care pharmacy were evaluated. Each half tablet weight was recorded using a digital electronic balance. Weight variability was determined by comparing actual half tablet weight to the theoretical half tablet weight and calculating the relative standard deviation. Results showed that weight variability occurred in half tablets of unscored tablets of Paxil 40 mg, Risperdal 2 and 4 mg, and scored tablets of Zoloft 100 mg. Half tablets of scored Paxil 20 mg tablets did not show weight variability, resulting in uniform half tablet dosages. The authors concluded that tablet splitting does not generally produce uniform and equal half tablet doses, and that split tablets should be evaluated using weight variation criteria before tablet splitting programs are initiated.