Pharmaceutica Analytica Acta

Abstract

Automated Flow Injection Techniques in Pharmaceutical Analysis: A Useful tool

Paraskevas D. Tzanavaras

Automation is a critical demand in modern pharmaceutical analysis and quality control, since strict legislation regarding Good Laboratory (GLP) and Manufacturing Practice (GMP) require extensive analyses of huge amounts of samples during all stages of the manufacturing process of a pharmaceutical formulation. The scope of this editorial is to highlight the usefulness of automated flow-injection based analytical techniques in the field of pharmaceuticals quality control. Particular attention will be paid to chemiluminescence detection, flow optosensors and the relatively novel concept of Sequential Injection Chromatography (SIC). Flow injection based automated analytical techniques include a well-established group of techniques with numerous widespread applications in quantitative chemical analysis. The most popular representatives are Flow (FI) and Sequential Injection Analysis (SI). In contrast to conventional batch and continuous flow procedures, FI and SI do not rely on complete mixing of sample and reagent(s) (physical homogenization). Combined with the inherent exact timing of all events it is neither necessary to wait until all chemical reactions have proceeded to equilibrium (chemical homogenization). These features, that allow transient signals to be used as the readout, do not only permit the procedures to be accomplished within a very short time (typically in less than 30 s), but have open new and novel avenues to perform an array of chemical analytical assays, which are either very difficult and in many cases directly impossible to implement by traditional means [1]. Representative FI and SI manifolds can be found in Figures 1 and 2 respectively, while the interested reader can find many articles describing the principles of operation [2-4]. Among the numerous automation potentials of these techniques in pharmaceutical analysis some particularly interesting features including: (i) derivatization reactions; (ii) on-line dilution; (iii) on-line solid phase extraction; (iv) on-line solvent extraction.