Quality Control Measurement and in vitro Bioequivalence of Candesartan Cilexetil Tablets Marketed in Saudi Arabia

Aim: Some generics were reported to be counterfeit and inferior quality than the innovators. This study was aimed to make sure about the compliance with standard specifications and evaluation of the quality of different selected brands (generic and innovator), after performing different pharmacopeial quality control tests, of Candesartan cilexetil tablets (16 mg) commercially available in Saudi Arabia for hypertensive patients.

Study Design: In vitro study of tablets.

Place and Duration of Study: College of Pharmacy, Jazan University, Jazan, KSA, between September 2018 and May 2019.

Methodology: The different generic brands of Candesartan cilexetil (CC) and innovator brand (16 mg) were subjected to weight variation, hardness, friability, assay, and disintegration tests following the established protocols. The purity of active ingredient was authenticated by comparative analysis of FT-IR spectra with pure drug. In vitro bioequivalence was studied after analyzing the results of dissolution summaries in phosphate buffer (pH 6.5) mixed with polysorbate 20 (0.35% v/v).

Results: The results of the tests conducted for evaluation of the tablets were found to be in acceptable limits for all the selected brands. After comparative analysis of FT-IR spectra with pure drug, it was inferred that correct active ingredient was used for the preparation of tablets. The drug release profile exhibited 96.89 – 101.97% of release of CC from all generic brands, in comparison to 99.4% for innovator brand after 60 min of study. The assessment of difference factor (f1<15) and similarity factor (f2>50) revealed the resemblance of generic brands with that of innovator brand. Furthermore, the dissolution efficiency (DE = ±10% of the innovator value) of all generic brands (73.12 – 73.25%) exhibited equivalency with that of innovator brand (70.45%).

Conclusion: The selected generics were considered to be biopharmaceutically equivalent to the innovator and maintained their efficacy. As a consequence, these brands can be used interchangeably by the hypertensive patients in Saudi Arabia.