Principles and applications of Chromatography & HPLC

HIGH-performance liquid chromatography (HPLC) is an important instrument used in the pharmaceutical industry for evaluations and quality control of a large variety of samples.

- P Mandal

It is a chromatographic method that is used to separate a mixture of compounds in analytical chemistry, biochemistry and especially in pharmaceutical industries so as to identify, quantify or purify the individual components of the mixture. It is a method of choice for checking purity of new chemical entities, monitoring changes in synthetic procedures or scale up, evaluating new formulations, and carrying out quality control and the assurance of the final drug product. The present article gives a brief overview of modern HPLC method development especially for pharma industry.

Rapid high-performance liquid chromatography method could improve formulation quality control studies. Researchers say the novel high-performance liquid chromatography with diode-array detection method can be utilised in routine quality control analysis of levofloxacin in pharmaceutical formulation and bioequivalence studies.

Chromatography and HPLC

Selectivity and detectability optimization are the primary goals in HPLC separations. The separation principle of HPLC is based on the distribution of the analyte (sample) between a mobile phase; called eluent and a stationary phase; usually the packing material of the column, which is stationery. Depending on the chemical structure of the analyte, the molecules are retarded while passing the stationary phase.

In gas chromatography (GC), the mobile phase is a gas and the analytes need to have sufficient volatility to pass through the column. In addition, the analytes need to be stable at the temperatures exposed to in the injector and/or in the column. Analytes that are not volatile, for example, fatty acids, can be made volatile by derivatization, e.g., the fatty acids can be converted to esters.