Drug Loss due to Grinding, Sifting and Automatic Packaging of Carvedilol Tablets

Abstract

Recently, at very low doses, carvedilol has improved the treatment of chronic heart failure. In Tenri Hospital, prescriptions for low dose carvedilol had been prepared by grinding a 10 mg tablet, adding lactose to it, and packaging the resulting powder. However, the drug loss in these processes had been causing problems in treating chronic heart failure. The present study examines the extent of drug loss in the grinding, sifting, and automatic packaging processes and the causes.
The overall drug loss rate, as calculated by measuring the weight of the powder in the finished package, was 24.8±12.8, 33.9±13.2, and 28.0±9.3% for the 1.25, 2.5, and 5 mg packages, respectively, a considerable loss. The greatest loss was found to occur in the automatic packaging process. The drug loss rates for carvedilol itself were 56.4±8.1, 50.2±10.2, and 36.9±7.5% for the 1.25, 2.5, and 5 mg packages, respectively. The loss of carvedilol was greater for the 1.25 and 2.5 mg packages than the 5 mg package (p<0.05).
These results suggest that the grinding of a 10 mg tablet gives rise to inaccurate dosing. Thus, low dose tablets available on the market should be used preferentially when low dosages of carvedilol are prescribed to patients with chronic heart failure.