AN INVESTIGATION ON THE DISSOLUTION OF NITROFURANTOIN

Document Type : Original Article

Authors

Department of Pharmaceutics, Faculty of Pharmacy, Assiut University, Assiut, Egypt

Abstract

The problem of the existence of interlot and inter-tablet variation in the dissolution rates of nitrofurantion (NFT) marketed tablets, attracts, the attention for investigating the microcrystalline NFT powder used in formu1ating the marketed tablet products. The x-ray diffractometry and the differential, scanning colorimetry of five microcrystalline NFT powders obtained from different manufacturers revealed that this drug is not exhibiting polymorphism. NFT hydrates of large particle size were observed to be formed when the drug was to be in contact with water with the pH values in the acidic range. The unexpected dissolution - PH profile of stored NFT suspensions prepared by precipitation at pH 5.4 from alkaline solution may be illustrated by the possibility of tautomeric transformations in the drug. This was more revealed by the observed reversible shift of the l maxima on changing the pH of its solutions.