Comparative Quality Evaluation of Three Commercial Brands of Candesartan Cilexetil/Hydrochlorothiazide (16/12.5 mg) Tablets Using HPLC and UV-Spectrophotometric Methods: A Study from Tripoli, Libya

Abstract

The fixed-dose combination of candesartan cilexetil/hydrochlorothiazide (16/12.5 mg) remains a first-line option in managing essential hypertension, owing to its complementary antihypertensive mechanisms. This study evaluated the physicochemical quality and drug content of three commercially available brands of this combination marketed in Tripoli, Libya. Three brands, coded A (Atacand Plus®, Sweden; innovator/reference), B (Atacand Plus, Turkey), and C (Hytacand, Algeria), were evaluated for weight variation, friability, hardness, thickness/diameter uniformity, and disintegration time in accordance with USP procedures. Drug content was determined using a previously validated HPLC method, with re-verification for system suitability, precision, and specificity under local analytical conditions of this study. A UV-spectrophotometric method was additionally validated in terms of linearity, limit of detection (LOD), and limit of quantitation (LOQ). All brands complied with pharmacopoeial limits, showing friability values of 0.054–0.197%, disintegration time of 3.41–5.17 minutes, and weight variation within the ±7.5% limit. Tablet hardness ranged from 10.41 to 11.78 kgf, without adversely affecting friability or disintegration. The UV method showed acceptable linearity for candesartan cilexetil (R² = 0.9960) and hydrochlorothiazide (R² = 0.9997). HPLC assay results ranged from 99.01–100.85% for candesartan cilexetil and 100.52–102.48% for hydrochlorothiazide, all within the 90–110% acceptance criterion. These findings confirm consistent drug content across the three brands despite differences in manufacturing origin. System precision showed low variability, with %RSD values of 0.107% for candesartan cilexetil and 0.138% for hydrochlorothiazide. Chromatographic specificity, confirmed by a resolution value of 4.46, further supported method reliability. All three brands met the pharmacopoeial and analytical requirements assessed, indicating comparable pharmaceutical performance among the tested products. Given the observed compliance of all tested brands, routine post-marketing quality monitoring remains warranted to ensure sustained therapeutic equivalence among multisource candesartan/hydrochlorothiazide products in the Libyan market.