[Determination of rizatriptan in pharmaceutical dosage forms using capillary gas chromatography]

An analytical method based on capillary gas chromatography with flame ionization detector [GC-FID] was developed for the direct analysis of rizatriptan benzoate [RZB] without derivative reaction, in pure and pharmaceutical dosage forms using metronidazole benzoate [MNZB] as internal standard [IS]. The RZB and MNZB [IS] were dissolved in methanol and chromatographed on a TRB-5 column [30m x 0.25 mm, 0.25 micro m], the temperature of GC oven was as follows: initial temperature was 190°C, held for 2 mm, increased finally to 235°C at 15°C/mm with a final hold of 2 mm., with a nitrogen as carrier gas with flow rate 2 mL/min and FID detection. The injector port and detector temperatures were maintained at 270°C and 260°C respectively. The method had a chromatographic total run time of 7 mm. The retention times were about 4.9 and 5.69 mm for RZB and IS, respectively. Results of assay and recovery studies were statistically evaluated for its accuracy and precision. The calibration graph of peak area ratio was rectilinear in the concentration range 4-90 micro g/mL of RZB, with a relative standard deviation not exceeds 2.03%. The limit of detection was 0.42 micro g/mL, and the limit of quantitation was 1.39 micro g/mL. Correlation coefficient [R[2]] of the regression equation was greater thane 0.999. No interference from any components of pharmaceutical dosage forms was observed

[Extractive spectrophotometric determination of isopropamide iodide in its pharmaceutical formulations using bromophenol blue, eosine Y and amido black]

We developed simple, rapid, accurate, precise and sensitive spectrophotometric methods for the determination of ISPI in tables. The proposed methods are based on the formation of ion-pair complexes between the examined drug with BPB, AB in alkaline buffer at pH [9.0-9.5] and EO in buffer at pH=6.5, the complexes were extractable with dichloromethane which can be measured at the optimum lambda [max]. beer's law is obeyed in the concentration ranges a 0.96-14.4 micro g.ml[-1], 0.481-7.213 micro g.ml[-1] and 0.962-28.85 micro g.ml[-1] for the complexes ISPI-BPB, EO-ISPI and AB-ISPI respectively. The proposed methods were directly and easily applied to ISPI pharmaceutical preparations with accuracy, with results from recovery experiments ranging between 99.22 and 100.10% for BPB, 98.55 and 102.29% for EO and 98.75 and 101.93% for AB methods. The low relative standard deviation values indicate good precision and high recovery values indicate accuracy of the proposed methods. Therefore the proposed methods have been successfully applied to the determination of drug in commercial tablets