Interchangeability for brands of promethazine teoclate (25mg) tablets available in Abuja metropolis of Nigeria.
Nneka N. Ibekwe , Johnson A. Isaac , Adedolapo Ajiboye , Obi P. Adigwe
Department of Medicinal Chemistry and Quality Control, National Institute for Pharmaceutical
Research and Development (NIPRD), Abuja, Nigeria.
2Department of Pharmaceutical Technology and Raw Materials Development, National Institute for
Pharmaceutical Research and Development (NIPRD), Abuja, Nigeria.
3Office of the Director-General, National Institute for Pharmaceutical Research and Development (NIPRD), Abuja, Nigeria.
Corresponding author: Johnson A. Isaac
Email: ajeh.johnson@niprd.gov.ng Telephone :+234 8039185040
ABSTRACT
Background: Quality assessment of pharmaceutical products is a very critical aspect of medicinal chemistry due to the surge in fake and substandard products especially in developing countries that would rely heavily on generics for their health care needs.
Objective: To access the quality of band of promethazine teoclate tablets marketed in Nigeria.
Methods: Herein, we report a mathematical approach for predicting bioequivalence and interchangeability of common brands of promethazine teoclate tablets (25 mg) available in Abuja metropolis of Nigeria. Using compendia guidelines (the British and United States) we assessed tablets quality for assay, friability, hardness, disintegration, dissolution, identity, thickness and diameter, and weight variation.
Results: All brands (7) tested complied with specifications for friability, disintegration, thickness, diameter, and weight variation while three (3) brands complied with BP specifications for the assay test. Only two brands released at least 80 % of its active ingredient after 30 minutes. The apparent variations in their release profiles led to an in vitro bioequivalence study by fitting their dissolution profiles into similarity (f2) and dissimilarity (f1) equations, and subsequently dissolution efficiency (DE) equation. Only one brand could be considered interchangeable with the
innovator brand. Further study revealed that drug release profile of 25 mg promethazine teoclate follows the super cell II transport mechanism.
Conclusion: Our study reaffirmed the need for routine quality assessment if we must defeat the circulation of fake and substandard products.
Keywords: Similarity factor, dissimilarity factor, dissolution efficiency, mean dissolution time, promethazine, drug release kinetic model.