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

ABSTRACT

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