Discriminatory Dissolution Test for Tablets Containing a- and b-Thalidomide Polymorphs

Abstract

Over the years, thalidomide has been prescribed for an increasing number of diseases, including multiple myeloma and erythema nodosum leprosum. In Brazil and other countries, thalidomide is available in tablets, and there is no official dissolution testing available for this dosage form. Considering this, a dissolution method was developed and validated for tablets containing 100 mg of each polymorph using 1-L vessels to verify that it can differentiate between polymorphs, since drug product is supposed to be formulated with the α form. In addition, the possibility of using smaller volumes of dissolution medium was also explored.This method was compared with the USP dissolution method for thalidomide capsules (4-L vessel) with independent models using difference and similarity factors as well as dissolution efficiency. Dissolution kinetics was evaluated using zero-order, first-order, Higuchi, and Korsmeyer-Peppas models. The kinetic parameters and the suitability of the models for experimental data were evaluated. The developed dissolution method was fully validated. It allowed a better discrimination of thalidomide polymorphs than the USP method for the formulations tested. Considering that it uses a conventional dissolution apparatus with 1-L vessels and there is no method described for tablets, it can be used for quality control of thalidomide in this dosage form.

An Alternative Method for the Dissolution of Enrofloxacin Tablets

“…The parameter dissolution efficiency (DE) was used to characterize the drug release profile of the dosage form (15,16). DE is the area under the curve within a time range and is expressed as a percentage (17).…”