Pharmaceutical and analytical standardization of Varadi Kwatha Churna: an ayurvedic polyherbal formulation

Varadi Kwatha Churna (VK) is a classical Ayurvedic preparation containing six ingredients, such as Haritaki (Terminalia chebula Retz), Bibhitaki (Terminalia bellirica (Gaertn.) Roxb.), Amalaki (Phyllanthus emblica L.), Daruharidra (Berberis aristata DC.), Musta (Cyperus rotundus L.), and Devdaru (Cedrus deodara Roxb. Ex D.Don). mentioned in the Sharanadhara Samhita, is an established polyherbal formulation in a solid dosage form. It is used in the management of Prameha (polyuria disorders). Pharmaceutical and quality control standardization are essential to ensure the quality, safety, and efficacy of VK formulation. A comprehensive evaluation of its phytochemistry, pharmacological activity, safety parameters, and batch-to-batch consistency is required for regulatory validation. The present study established VK formulation’s standard operating procedures (SOPs), and quality control (QC) standards. Three batches of VK were prepared in-house at a Good Manufacturing Practice (GMP)-certified pharmacy using the traditional method described in the Ayurvedic Formulary of India (AFI) for Kwatha Churna (coarse powder). QC parameters, such as powder microscopy and phytochemical analysis, involved the quantification of Gallic acid, Berberine, and Palmatine via High-Performance Thin-Layer Chromatography (HPTLC), using a mobile phase of toluene: ethyl acetate: formic acid: methanol (5:4:1:1). To ensure the safety and quality of samples, comprehensive evaluations were conducted according to the standards set by the Ayurvedic Pharmacopoeia of India (API). These assessments include testing for heavy metal content, pesticide residues, and aflatoxins, as well as rigorous microbiological examinations to detect microbial contamination and specific pathogens. The average VK yield was 86.67%, and all raw drugs complied with the Ayurvedic Pharmacopoeia of India (API) standards. Physicochemical evaluation revealed a pH (10% aqueous solution) of 3.677 ± 0.015 and a loss on drying (LOD) of 8.186 ± 0.257% w/w for the compound. The extractive values were recorded at 28.08 ± 0.82% w/w for water-soluble and 37.353 ± 0.196% w/w for alcohol-soluble content, respectively. Ash analysis showed a total ash content of 2.69 ± 0.210% w/w and acid-insoluble ash content of 0.6833 ± 0.228% w/w. Assessment of flow properties indicated a bulk density of 0.607 ± 0.043 g/cm³, a tapped density of 0.457 ± 0.027 g/cm³, a Hausner ratio of 1.327 ± 0.020, and a compressibility index of 24.66 ± 1.155%. Furthermore, the formulation met the safety standards for heavy metal content and microbial load. The quantitative phytochemical markers were identified as gallic acid (2.283 µg/100 mg), berberine (33.96 µg/100 mg), and palmatine (263.4 µg/100 mg). The established SOP and QC parameters were successfully validated. Furthermore, this parameter can be established as a pharmacopoeial standard to ensure the reproducibility and consistency of the Varadi Kwath Churna formulation, thereby supporting its scalability and reliability in industrial production.