High-Performance Column Liquid Chromatographic Method for the Simultaneous Determination of Buclizine, Tryptophan, Pyridoxine, and Cyanocobalamin in Tablets and Oral Suspension

An HPLC method was developed and validated for the simultaneous determination of buclizine, tryptophan, pyridoxine, and cyanocobalamin in pharmaceutical formulations. The chromatographic separation was carried out on an RP-C18 column using a mobile phase gradient of methanol, 0.015 M phosphate buffer (pH 3.0), and 0.03 M phosphoric acid at a flow rate of 1.0 mL/min and UV detection at 230, 280, and 360 nm, respectively, for buclizine, tryptophan, pyridoxine, and cyanocobalamin. The method validation yielded good results with respect to linearity (r > 0.999), specificity, precision, accuracy, and robustness. The RSD values for intraday and interday precision were below 1.82 and 0.63%, respectively, and recoveries ranged from 98.11 to 101.95%. The method was successfully applied for the QC analysis of buclizine, tryptophan, pyridoxine, and cyanocobalamin in tablets and oral suspension.

Development and Validation of a Reversed-Phase Column Liquid Chromatographic Method for the Determination of Five Cephalosporins in Pharmaceutical Preparations

A new, simple, rapid, and precise RP-HPLC method has been developed and validated for the determination of five cephalosporins, namely, cefalexin, cefoperazone, ceftriaxone, ceftazidime, and cefepime. The method has been applied successfully for simultaneous determination of cefalexin in a binary mixture with sodium benzoate in a suspension, and cefoperazone in a binary mixture with sulbactam in vials. Chromatographic separation was achieved on a Waters μBondapak® C18 column (250 × 4.6 mm id, 10 μm particle size) using the mobile phase monobasic potassium phosphate (50 mM, pH 4.6)–acetonitrile (80 + 20, v/v) with UV detection. A flow rate of 1 mL/min was applied. Linearity, accuracy, and precision were found to be acceptable over the concentration range of 30–300, 3–30, and 15–120 μg/mL for the studied cephalosporins, sodium benzoate, and sulbactam, respectively. The optimized method proved to be specific, robust, and accurate for QC of the cited drugs in their pharmaceutical preparations.

Development and Validation of a Reversed-Phase Column Liquid Chromatographic Method for the Determination of Five Cephalosporins in Pharmaceutical Preparations

A new, simple, rapid, and precise RP-HPLC method has been developed and validated for the determination of five cephalosporins, namely, cefalexin, cefoperazone, ceftriaxone, ceftazidime, and cefepime. The method has been applied successfully for simultaneous determination of cefalexin in a binary mixture with sodium benzoate in a suspension, and cefoperazone in a binary mixture with sulbactam in vials. Chromatographic separation was achieved on a Waters μBondapak® C18 column (250 × 4.6 mm id, 10 μm particle size) using the mobile phase monobasic potassium phosphate (50 mM, pH 4.6)–acetonitrile (80 + 20, v/v) with UV detection. A flow rate of 1 mL/min was applied. Linearity, accuracy, and precision were found to be acceptable over the concentration range of 30–300, 3–30, and 15–120 μg/mL for the studied cephalosporins, sodium benzoate, and sulbactam, respectively. The optimized method proved to be specific, robust, and accurate for QC of the cited drugs in their pharmaceutical preparations.

Validation of a Column Liquid Chromatographic Method for the Analysis of Pramipexole and Its Five Impurities

In this paper, a previously optimized method for HPLC analysis of pramipexole and its impurities was subjected to method validation in accordance with official regulations. The optimized chromatographic conditions were as follows: mobile phase acetonitrilewater phase [15 + 85, v/v, water phase contained 1 triethylamine (TEA), pH adjusted to 7.0 with orthophosphoric acid]; detection at 262 nm for pramipexole, BI-II 751 xx, BI-II 786 BS, BI-II 820 BS, and 2-aminobenzothiazole and at 326 nm for BI-II 546 CL; column temperature, 25C; and flow rate, 1 mL/min. Acetonitrile and TEA content, pH of the water phase, flow rate, column temperature, and column type were factors studied in robustness testing. According to the experimental plan defined by a Plackett-Burman design, five dummy variables were added in order to have 12 factors. As output, resolution factor was chosen. Robustness was assessed by graphical (half-normal probability plots and Pareto charts) and statistical (t-test) methods. Also, nonsignificance intervals for significant factors were estimated, and limits for the system suitability test were determined. Finally, linearity, accuracy, and precision of the proposed HPLC method were defined. LOD and LOQ values for analyzed impurities were determined. The method was completely defined by these experiments.

Simultaneous Estimation of Acetylsalicylic Acid and Clopidogrel Bisulfate in Pure Powder and Tablet Formulations by High-Performance Column Liquid Chromatography and High-Performance Thin-Layer Chromatography

This paper describes validated high-performance column liquid chromatographic (HPLC) and high-performance thin-layer chromatographic (HPTLC) methods for simultaneous estimation of acetylsalicylic acid (ASA) and clopidogrel bisulfate (CLP) in pure powder and formulations. The HPLC separation was achieved on a Nucleosil C8 column (150 mm length 4.6 mm id, 5m particle size) using acetonitrilephosphate buffer, pH 3.0 (55 + 45, v/v) mobile phase at a flow rate of 1.0 mL/min at ambient temperature. The HPTLC separation was achieved on an aluminum-backed layer of silica gel 60F254 using ethyl acetatemethanoltolueneglacial acetic acid (5.0 + 1.0 + 4.0 + 0.1, v/v/v/v) mobile phase. Quantitation was achieved with UV detection at 235 nm over the concentration range 424 g/mL for both drugs, with mean recoveries of 99.98 0.28 and 100.16 0.66 for ASA and CLP, respectively, using the HPLC method. Quantitation was achieved with UV detection at 235 nm over the concentration range of 4001400 ng/spot for both drugs, with mean recoveries of 99.93 0.55 and 100.21 0.83 for ASA and CLP, respectively, using the HPTLC method. These methods are simple, precise, and sensitive, and they are applicable for the simultaneous determination of ASA and CLP in pure powder and formulations.