Commercially available folic acid supplements and their compliance with the British Pharmacopoeia test for dissolution

A recent report suggested that some folic acid preparations available in th e United States failed to meet the specifications for dissolution specified by the US Pharmacopoeia (USP), of 70 per cent drug release in the first ho ur of testing. The Teratology Society recommends that women of childbearing age should take a daily supplement of 400 mug folic acid when they are try ing to conceive, to reduce the risk of foetal neural tube defects. The cons equence of this failure to meet the USP requirements may be that an inadequ ate dose of folate may be absorbed and thus the expected level of protectio n against neural tube defects not afforded. The purpose of the present stud y was to examine a number of brands of folic acid (400 mug), available comm ercially in the United Kingdom, for compliance with the British Pharmacopoe ia (BP) test for dissolution. Ten tablets (or capsules) from each of 11 bra nds were tested using dissolution apparatus compliant with BP requirements, using 0.1 M sodium hydroxide as the dissolution medium. The results indica ted that four of the brands failed to release 70 per cent of the nominal dr ug content in the first hour of test and thus did not comply with the test. Two of the seven brands that passed the test went on to release more than 150 per cent of the nominal 400 mug drug content. These results highlight t he problems of dose uniformity and the potential health risks of slow disso lution and under-dosing in commercially available folic acid dosage forms.