Ecofriendly Q-Absorbance Ratio Spectrophotometric Method for Simultaneous Quantification of Rifampicin and Quercetin in Liquisolid Dosage Form

A sensitive, quick, precise, accurate, robust, and ecofriendly Q- absorption ratio spectrophotometric technique was developed and validated for estimation of Rifampicin and Quercetin in two dissolution media pH - 6.8 phosphate buffer and 0.1 M Hydrochloric acid and successfully applied for estimation of liquisolid formulation. Rifampicin and Quercetin showed an iso-absorptive point at 420 and 411 nm in pH - 6.8 phosphate buffer and 0.1 M Hydrochloric acid respectively. The second wavelength used was 368 and 367 nm which is λmax of Quercetin in pH - 6.8 phosphate buffer and 0.1 M Hydrochloric acid respectively. The concentration of the drugs was determined by using ratio of absorbance at iso-absorptive point and at the λmax of Quercetin. This method is linear for Rifampicin; in range of 2–12 μg/ml (R2 > 0.9970) and for Quercetin; in the range of 2-12 μg/ml (R2 > 0.9995) in both dissolution media. The % Recovery was 95.18 – 98.15 % of Rifampicin and 93.58 – 97.89 % of Quercetin by standard addition method. The method was found to be precise as % RSD was less than 2.00 in Repeatability, Interday and Intraday precision. The % assay of drugs in liquisolid formulation was found to be 95.79 % for Rifampicin and 96.29 % for Quercetin which showed good applicability of the developed method. Moreover, the novel Analytical GREEnness (AGREE) metrics, the analytical eco-scale, and the green analytical procedure index (GAPI) were utilized to evaluate the developed technique’s environmental sustainability.