ABSTRACT
The numbers of analyses of drugs in biological fluids carried out in laboratories throughout the world run into millions per year. This chapter briefly describes less popular methods of analysis with an indication of their applicability. Microbiological methods of drug assay are among the few bioassays for drugs where the biological effect rather than chemical or physicochemical properties of the drug was used to measure its concentration in unknown samples. In the serial dilution method of analysis, the sample is incubated in a liquid nutrient containing viable microorganisms. The hippuric acid can be readily extracted from the incubation system and the enzyme activity determined according to conventional methods. Flow injection analysis is an analytical technique has attracted much theoretical and practical development, particularly in pharmaceutical analysis where there is a demand for the monitoring of materials and where the demands of sensitivity and specificity are not great, such as analysis of caffeine, corticosteroids, and codeine in tablets.
