International Journal of Pharmaceutical Chemistry and Analysis

“Solid as Solvent” - Novel Approach for Spectrophotometric Analytical Technique for Nalidixic Acid Tablets using Solids (Eutectic Liquid Of Phenol and Metformin Hydrochloride) as Solubilizing Agents

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Author Details: R K Maheshwari*, Priya George, Akshay Fouzdar, Sugandha Singh

Volume : 2

Issue : 1

Online ISSN : 2394-2797

Print ISSN : 2394-2789

Article First Page : 42

Article End Page : 45


 The present investigation is an attempt to show that solids can also be wisely used to act as solvent precluding the use of organic solvents. In the present study, a eutectic liquid (PMHCl 41) obtained by triturating phenol crystals and metformin hydrochloride in 4:1 ratio on weight basis was employed to extract (dissolve) the nalidixic acid from fine powder of tablets. Distilled water was used for dilution purpose to carry out spectrophotometric estimation at 330 nm without utilizing any organic solvent. The solubility of nalidixic acid in distilled water at room temperature was found to be 0.21 mg/ml while the solubility of nalidixic acid in PMHCl 41 was more than 180 mg per ml (of PMHCl 41). Proposed spectrophotometric analytical method is novel, free from organic solvent, accurate and reproducible. The accuracy, reproducibility and precision of the proposed method were confirmed by recovery studies and statistical data. The presence of tablet excipients, phenol and metformin hydrochloride did not interfere in the spectrophotometric estimation at 330 nm. Phenol and metformin hydrochloride do not interfere above 300 nm.


Keywords: Mixed-solvency concept, nalidixic acid, phenol, metformin hydrochloride, spectrophotometric analysis, eutectic liquid.