Avaliação da uniformidade de doses em comprimidos sulcados submetidos à partição

Abstract

Splitting tablets has become increasingly common in many countries, being performed by health professionals and patients. Partition is performed to obtain prescribed doses that are unavailable, for gradual increase or decrease doses, to obtain the minimum safe dose at the beginning of therapy, to adjust responses to individual treatments or for economic reasons. However, tablets may have their quality affected when they are broken. Factors such as intrinsic quality of the tablets, accuracy of the method employed, weight loss of tablets during the process and individual skill to perform the splitting may lead to impairment of the dose obtained. This study aimed to evaluate the uniformity of doses of carbamazepine tablets 200 mg and atenolol 50 mg, both scored, that were split by homemade knife and cutter appliance. The study also evaluated if partition of scored tablets provides acceptable levels of drug in their respective halves, if the splitting methods that were used differed, and influence the dosage of medication dose uniformity after they are broken. Tests to determine weight, determination of content uniformity and doses in tablets whole and split were made. Carbamazepine and atenolol tablets, integers, were within pharmacopoeial specifications for weight determination and dose uniformity. However, after splitting, either homemade knife or cutter unit, values of acceptance observed overcame quite pharmacopoeial limits. There was no significant difference between the methods of partition, nor influence the dosage of drugs on its uniformity. However, it was also found that both methods partition have the ability to generate fragments at doses below 75% and above 125%, which was not observed when measuring the tablets whole. Thus, partition of scored tablets analyzed proved not recommended because of such wide variations in doses obtained, which can cause problems of efficacy and safety.