Domperidone (DOM) is a drug used as an antiemetic and to control gastrointestinal effects of dopaminergic drugs in the management of perkinsonism. Two simple, rapid, sensitive and selective extraction free spectrophotometric methods have been developed for the assay of DOM in pure drug, in pharmaceuticals and in spiked human urine sample. The methods are based on the formation of yellow ion-pair complexes between DOM and two sulphonphthalein dyes viz., thymol blue (method A) and bromothymol blue (method B) in acetone and dichloromethane medium. The complexes showed absorption maxima at 390 nm and 410 nm in method A and method B, respectively. Reaction conditions were optimized to obtain the maximum color intensity. The absorbance was found to increase linearly with increase in concentration of DOM, which was corroborated by the calculated correlation values of 0. . The composition of the ion-pairs was found to be 1 : 1 by Job's method and the conditional stability constant (K f ) of the complexes have been calculated. The proposed methods were applied successfully to the determination of DOM in tablets as well as in spiked urine sample with good accuracy and precision.

A simple, selective and cost effective spectrophotometric method has been described for the determination of olanzapine (OLP) in bulk drug and in tablets. The method involves treating OLP with an excess of iodate in acid medium followed by the determination of liberated iodine by reacting with a fixed amount of Nile blue and measuring the absorbance at 400 nm. In this method, the amount of iodine reacted corresponds to the OLP concentration. The experimental conditions for the assay have been optimized and the absorbance is found to increase linearly with the concentration of OLP (r = 0.997). Beer's law is obeyed over the range 15-120 ?g mL-1. The calculated molar absorptivity and Sandell sensitivity values are 0.657?103 l mol-1 cm-1 and 0.475 ?g cm-2, respectively. The limits of detection (LOD) and quantification (LOQ) are 3.93 and 11.90 ?g ml-1. The performance of the method was validated according to the present ICH guidelines. The repeatability and intermediate precision, expressed by the RSD was better than 3%. The accuracy of the method expressed as relative error was satisfactory. The proposed method was applied to the analysis of tablet form of OLP and the results tallied well with the label claim. No interference was observed from concomitant substances normally added to tablets. The results were statistically compared with those of a literature method by applying the Student's t-test and F-test. The accuracy and validity of the method were further ascertained by performing recovery studies via spike method.

Two titrimetric and two spectrophotometric methods are described for the assay of famotidine (FMT) in tablets using N-bromosuccinimide (NBS). The first titrimetric method is direct in which FMT is titrated directly with NBS in HCl medium using methyl orange as indicator (method A). The remaining three methods are indirect in which the unreacted NBS is determined after the complete reaction between FMT and NBS by iodometric back titration (method B) or by reacting with a fixed amount of either indigo carmine (method C) or neutral red (method D). The method A and method B are applicable over the range of 2–9 mg and 1–7 mg, respectively. In spectrophotometric methods, Beer's law is obeyed over the concentration ranges of 0.75–6.0 μg mL−1 (method C) and 0.3–3.0 μg mL−1 (method D). The applicability of the developed methods was demonstrated by the determination of FMT in pure drug as well as in tablets.