Dosage form % Founda of atenolol Proposed method Official method [1] Ateno® tabletsb 100.86 98.78 100.59 99.48 99.15 99.47 Mean ± S.D. 100.20 ± 0.92 99.24 ± 0.40 t 1.65 F 5.25 Blokium 100® tabletsc 99.69 100.18 101.02 100.02 99.28 99.59 Mean ± S.D. 100.00 ± 0.91 99.93 ± 0.31 t 0.12 F 8.89 Tenormin® tabletsd 101.43 100.52 100.09 100.60 100.73 100.95 Mean ± S.D. 100.75 ± 0.67 100.69 ± 0.23 t 0.15 F 8.59 a The average of three separate determinations. b Labeled to contain 50 mg atenolol per tablet; manufactured by Egyptian International Pharmaceutical Industries Co. (EIPICO), 10th of Ramadan City, Egypt; batch number 053901. c Labeled to contain 100 mg atenolol per tablet; manufactured by Medical Union Pharmaceuticals Co., Abu-Sultan, Ismailia, Egypt; under license of Almirall Prodesfarma, Spain; batch number 042281. d Labeled to contain 50 mg atenolol per tablet; manufactured by Kahira Pharmaceutical & Chemical Industries Co., Cairo, Egypt; under license of AstraZeneca, UK; batch number 0510116. N.B. Tabulated t-value at P=0.05 is 2.78, tabulated F-value at P=0.05 is 19.00.

Table 9: Assay results for the determination of atenolol in commercial tablets by the HPLC and official methods.