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Abstract

Three simple, rapid, reliable and cost-effective methods based on titrimetry and spectrophotmetry in non-aqueous medium are described for the determination of ranitidine in pharmaceuticals. In titrimetry, the drug dissolved in glacial acetic acid was titrated with acetous perchloric acid with visual and potentiometric end point detection, crystal violet being used as indicator for visual titration. Spectrophotometry involved adding different amounts of the drug to a fixed amount of perchloric acid-crystal violet mixture followed by measurement of absorbance at 570 nm. The absorbance was found to increase linearly with the concentration of the drug and formed the basis for quantification. The titrimetric methods are applicable over 1-15 mg range of ranitidine, and in spectrophotometry, calibration graph was linear from 10 to 70 µg ml -1 . The apparent molar absorptivity is calculated to be 2.2 × 10 3 l mol -1 cm -1 and the calculated Sandell sensitivity is 161.7 ng cm -2 . The limits of detection and quantification are found to be 1.07 and 3.58 µg ml -1 , respectively. The procedures were used to determine ranitidine in pharmaceutical products and the results were found to be in good agreement with those obtained by the reference method. Associated pharmaceutical materials did not interfere. The accuracy and reliability of the methods were further ascertained by recovery studies via standard-addition technique with percent recoveries in the range 96.3 to 102.5 %.

Instrumental analysis of some anti-ulcer drugs in different matrices

“…[8] Another spectrophotometric method was developed depending on addition of fixed amount of perchloric acidcrystal violet mixture to different amounts of ranitidine and measuring the absorbance spectrophotometrically at λ max 570 nm. [9] Two spectrophotometric methods were developed for determination of ranitidine HCl. The first method was a kinetic spectrophotometric method based on the catalytic effect of ranitidine on the reaction between sodium azide and iodine and measuring the decrease in iodine absorbance at λ max max 348 nm.…”

Sensitive Bromatometric Methods for the Determination of Sumatriptan Succinate in Pharmaceutical Formulations

“…Two simple and sensitive spectrophotometric methods for the analysis of sumatriptan from pharmaceutical dosage forms are reported here. The methods utilize bromate-bromide mixture and methyl orange and indigo carmine as reagents, which have successfully been used for the sensitive spectrophotometric determination of many bioactive substances [10][11][12][13][14][15][16] . The proposed methods have the advantages of speed and simplicity besides being accurate and precise and can be adopted by the pharmaceutical laboratories for industrial quality control.…”