“SOLID AS SOLVENTâ€: NOVEL SPECTROPHOTOMETRIC ANALYTICAL TECHNIQUE FOR QUANTITATIVE ESTIMATION OF TINIDAZOLE IN TABLETS USING SOLIDS (EUTECTIC LIQUID OF PHENOL AND LIGNOCAINE HYDROCHLORIDE) AS SOLUBILIZING AGENTS (MIXED SOLVENCY CONCEPT)

Abstract

As per the mixed solvency concept, every substance present in this universe has got solubilizing power. The substance may be a gas, liquid or solid. The present research work is an attempt to demonstrate the solubilizing property of solids. Also, the present research work is one of the examples which prove that solids can also be employed for spectrophotometric analysis of poorly soluble drugs in place of organic solvents. Tinidazole has got poor solubility in distilled water, while, significantly high solubility in a eutectic liquid of two solids, namely, phenol and lignocaine hydrochloride. Phenol and lignocaine hydrochloride were employed in 4:1 ratio to give eutectic liquid (PL 41). This eutectic liquid was employed to act as solvent to extract out the drug, tinidazole, from the fine powder of its tablets for spectrophotometric estimation at 318 nm. Necessary dilutions were done using distilled water. The solubility of tinidazole in distilled water is 5.38 mg/ml at room temperature while the approximate solubility in PL 41 is more than 200 mg/ml. Proposed method is novel, accurate, rapid and free from toxicity of organic solvents and reproducible. Recovery studies and statistical data proved the accuracy, reproducibility and precision of the analytical method employed. Tablet excipients together with phenol and lignocaine hydrochloride did not interfere at 318 nm. Keywords - Spectrophotometric analysis, mixed-solvency concept, tinidazole, phenol – lignocaine hydrochloride eutectic liquid