ABSTRACT
A Simple, rapid, specific, accurate, economical and precise UV spectrophotometric and RP-HPLC methods (inaccordance with ICH guidelines) were developed and validated for determination of Nortriptyline hydrochlorideand Pregabalin in tablet dosage form. The first method was based on Q - absorbance ratio, and absorbances ofboth drugs were determined at 239 nm (λmax of Nortriptyline Hydrochloride) and 235 nm (Iso-absorptive Point)when dissolved in methanol. It is found that Pregabalin does not have chromophoric group. To be UV-sensitive,it was compulsory to introduce chromophoric group in Pregabalin structure and make it UV-sensitive. This wasachieved by converting the primary amine group of Pregabalin through reaction with benzoyl chloride to formbenzoylated derivative of Pregabalin. Benzoylated Pregabalin was determined at 225 nm using UV-visiblespectrophotometer. The second method was based on RP-HPLC. The chromatographic separation was performedon an Inertsil ODS C18 column (250 x 4.6mmx 5 μm) with a mobile phase of 0.56 %w/v Sodium hexane sulphonicacid dissolved in water acetonitrile (50:50 %v/v, pH 4.5 adjusted with Glacial Acetic Acid) at flow rate of 1.0mL/min with DAD detection wavelength at 210 nm. Retention times of Nortriptyline Hydrochloride andPregabalin were 7.3894 min and 4.0506 min, respectively. Beer-Lambert’s law obeyed the concentration rangeof 2-12 μg/mL for Nortriptyline Hydrochloride and 10-60 μg/mL for Pregabalin. The results indicated that bothspectrophotometric and RP-HPLC methods were linear, accurate, precise and robust with RSD values less than0.2% and % recovery was within the standard limits (99 - 102%).
ABSTRACT
The present manuscript describe simple, sensitive, rapid, accurate, precise and economical Q-absorbance ratio method for the simultaneous determination of Rifampicin and Piperine in combined capsule dosage form. Absorbance ratio method uses the ratio of absorbances at two selected wavelengths, one which is an isoabsorptive point and other being the λ-max of one of the two components. Rifampicin and Piperine show an isoabsorptive point at 387 nm in methanol. The second wavelength used is 337 nm, which is the λ-max of Piperine in methanol. The linearity was obtained in the concentration range of 5-40 μg/ml for Rifampicin and 2-20 μg/ml for Piperine. The concentrations of the drugs were determined by using ratio of absorbances at isoabsorptive point and at the λ-max of Rifampicin. The method was successfully applied to pharmaceutical dosage form because no interference from the capsule excipients was found. The results of analysis have been validated statistically and by recovery studies.
ABSTRACT
The present manuscript describe simple, sensitive, rapid, accurate, precise and economical Q-absorbance ratio method for the simultaneous determination of cefpodoxime proxetil and ofloxacin in combined tablet dosage form. Absorbance ratio method uses the ratio of absorbances at two selected wavelengths, one which is an isoabsorptive point and other being the λ-max of one of the two components. Cefpodoxime proxetil and ofloxacin show an isoabsorptive point at 273.2 nm in methanol. The second wavelength used is 297 nm, which is the λ-max of ofloxacin in methanol. The linearity was obtained in the concentration range of 2-14 μg/ml for both cefpodoxime proxetil and ofloxacin. The concentrations of the drugs were determined by using ratio of absorbances at isoabsorptive point and at the λ-max of ofloxacin. The method was successfully applied to pharmaceutical dosage form because no interference from the tablet excipients was found. The results of analysis have been validated statistically and by recovery studies.