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The development and validation of a reversed-phase liquid chromatographic (LC) method for the determination of sibutramine hydrochloride monohydrate in capsules is described. An isocratic LC analysis was performed on a reversed-phase RP-18 column (250 x 4.6 mm id, 5 microm particle size). The mobile phase consisted of methanol-water-triethylamine (80 + 20 + 0.5, v/v/v), with pH adjusted to 5.65 with 85% phosphoric acid, and was pumped at a constant flow rate of 1.0 mL/min. Measurements were made at a wavelength of 223 nm. The calibration curve was linear over the range of 15-40 microg/mL [correlation coefficient (r2) = 0.9998]. The relative standard deviation (RSD) value for intraday precision was 0.84%. The RSD value for interday precision was 0.90%. Recoveries ranged from 99.64 to 100.66%. No interferences from the excipients were observed. Because of its simplicity and accuracy, the method is suitable for routine quality control analysis of sibutramine in capsules.

Ceftazidime (CFZ) is a broad spectrum parenteral beta-lactam antibiotic of the cephalosporin family. This paper reports the development and validation of an agar diffusion microbiological assay using the cylinder-plate method for determination of CFZ in powder for injection. The validation carried out yielded good results in terms of linearity, precision, accuracy, selectivity, and robustness. The assay is based on the inhibitory effect of CFZ upon the strain of Pseudomonas aeruginosa ATCC 27853 used as the test microorganism. The results of the assays were treated statistically by analysis of variance and were found to be linear (correlation coefficient = 0.999998) in the selected range of 8.0-32.0 microg/mL; precise [repeatability: relative standard deviation (RSD) = 1.11%; intermediate precision: between-day RSD = 1.37% and between-analyst RSD = 1.41%]; and accurate. The selectivity of the bioassay was evaluated by analysis of degraded samples at 50 degrees C, and the results were compared with a pharmacopeial liquid chromatographic method at the time 0, 24, and 48 h. The results demonstrated the validity of the proposed bioassay, which allows reliable quantitation of CFZ in pharmaceutical samples and can be used as a useful alternative methodology for CFZ analysis in routine quality control.