Development and validation of a Sequential Injection Chromatographic Assay Methods for Some Pharmaceutical Drugs

Abstract

The number of drugs introduced into the market is increasing every year. So analytical methods are necessary to ensure these drugs and other pharmaceutical formulations contain the correct amount of active compounds and excipients. Simultaneous estimation of drug combination is generally done by separation using chromatographic methods like HPLC, GC and CE etc. These methods are accurate and precise with good reproducibility, but the cost of analysis is quite high owing to expensive instrumentation, reagent and expertise. Hence it is worthwhile to develop simpler and cost effective method for simultaneous estimation of drugs for routine analysis of formulation. Therefore a successful development of SIC technology was conducted. A monolithic column and a miniaturized fiber optic spectrometer system were installed in a SIC system. Additionally, a new SIC method for the assay of phenothiazine in a pharmaceutical formulation and human urine sample has been developed. The assay method includes the separation and quantitative determination of promethazine, chlorpromazine and perphenazine. A solid-phase extraction procedure, for purposes of sample clean-up as well as drugs extraction and pre-concentration, was also developed. Another achievement was the development of five new methods utilizing sequential injection chromatography (SIC) technique. The first method was applied to the separation and simultaneous assay of atenolol and hydrochlorothiazide in bulk and pharmaceutical formulations. The second method was applied to the assay of norfloxacin and ciprofloxacin; the third one was applied to the separation and simultaneous assay of phenothiazine in human urine sample. The fourth was applied to the separation and simultaneous assay of promethazine in pharmaceutical formulations, while, the fifth one was applied to the separation amiloride and furosemide in pharmaceutical formulations. To gain their maximum efficiency, the experimental conditions (chemical and instrumental) for the newly adopted methods were optimized by chemometrics to set-up the optimum. The methods were also validated following the "International Union of Pure and Applied Chemistry" guidelines. In terms of range of linearity, weighing regression of calibration equation, correlation coefficient of linearity, accuracy, precision, repeatability, intermediate-precision, limit of detection, limit of quantification and sample frequency. The newly developed SIC technology could be utilized in further analytical methods for the assay of some drugs in pharmaceutical formulations and human fluids.