The chromatographic behaviour of cephalosporins in gel filtration chromatography, a novel method to separate high molecular weight impurities

Determination of Cephalexin Monohydrate in Pharmaceutical Dosage Form by Stability-Indicating RP-UFLC and UV Spectroscopic Methods

An ultra-fast liquid chromatographic method and two UV spectroscopic methods were developed for the determination of cephalexin monohydrate in pharmaceutical dosage forms. Isocratic separation was performed on an Enable C₁₈G column (250 mm × 4.6 mm i.d., 5 μm) using methanol:0.01 M TBAHS (50:50, v/v) as the mobile phase at a flow rate of 1.0 ml/min. The PDA detection wavelength was set at 254 nm. The UV spectroscopic method was performed at 261 nm and at 256–266 nm for the AUC method using a phosphate buffer (pH=5.5). The linearity was observed over a concentration range of 1.0–120 μg/ml for UFLC and both of the UV spectroscopic methods (correlation coefficient=0.999). The developed methods were validated according to ICH guidelines. The relative standard deviation values for the intraday and interday precision studies were < 2%, and the accuracy was > 99% for all of the three methods. The developed methods were used successfully for the determination of cephalexin in dry syrup formulation.

Analysis of cephalosporin antibiotics

A comprehensive review with 276 references for the analysis of members of an important class of drugs, cephalosporin antibiotics, is presented. The review covers most of the methods described for the analysis of these drugs in pure forms, in different pharmaceutical dosage forms and in biological fluids.

Chromatographic determination of polymerized impurities in meropenem

A method for the separation of polymerized impurities in meropenem has been developed by gel filtration chromatography (GFC). The chromatographic conditions included a Superdex peptide HR 10/30 column and the mobile phase consisting of 0.01 mol L(-1) sodium phosphate buffer (pH 7.0), at a flow rate of 0.8 mL min(-1). The wavelength of UV detector was set at 220 nm. The linear range was 0.08-10 microg (r=0.9998); relative standard deviation (R.S.D.)=0.5-1.5%; the LOD and LOQ were 2.4 and 12.4 ng, respectively. Specificity of the GFC was checked by switching the effluent of each peak on the GFC to a C18 trap column and analyzing the effluent by LC-MS. The result shows that for the determination of polymers, the gel filtration chromatography is a rather simple separation mode as compared to RPLC.

Chromatographic determination of high-molecular weight impurities in amoxicillin

The separation of high molecular weight impurities in amoxicillin has been examined by three methods of gel filtration chromatography (GFC) and reversed phase liquid chromatography (RPLC). Specificity of GFC was checked by applying the method for the determination of amoxicillin and its related impurities and linking of GFC and RPLC. The result shows that for the determination of polymers the gel filtration chromatography is a rather simple separation mode as compared to RPLC. Regarding the three gel filtration chromatographic methods, the separation on the Superdex peptide column is advantageous over other methods of determining amoxicillin polymers.