Abstract

A REVIEW ARTICLE – ECOFRIENDLY AND ECONOMIC ANALYTICAL METHODS USING HYDROTROPIC SOLUBILIZATION (TITRIMETRY, UV SPECTROPHOTOMETRY, TLC AND HPLC)

Yashi Thakur* and R. K. Maheshwari

ABSTRACT

Solvents constitute more than half the material used in the manufacture of active pharmaceutical industry. Class I organic solvents include 1,2- dichloroethane, benzene, 1,2-dichloroethene, carbon tetrachloride, 1,1,1-trichloroethane etc., class II organic solvents include acetonitrile, methyl cyclo hexane, chlorobenzene, chloroform, methylene chloride, nitro methane, ethylene glycol, pyridine, formamide, toluene, hexane, sulfolane, methanol, tetrahydrofuran, 2-methoxy ethanol, tetralin, 1,4- dioxane, 1,2-dimethoxy ethane, N,N-dimethylformamide, N,N– dimethylacetamide, trichloroethylene, N–methylpyrrolidone, methylbutyl ketone, cyclohexane, 2–ethoxyethanol etc. and class Ⅲ organic solvents include ethanol, acetone, ethyl acetate, acetic acid, anisole, cumene, heptane, pentane, ethyl formate, propyl acetate, methyl acetate, 1-butanol, 2-butanol, butyl acetate, ethyl ether, dimethyl sulfoxide, trimethyl amine, formic acid, 1-pentanol, isobutyl acetate etc. Most of the organic solvents are used to perform thin layer chromatography (TLC), UV spectrophotometric estimation, HPLC and titrimetric analysis. Most of these organic solvents are hazardous to human health. Some of them are carcinogenic. Most of the organic solvents are costly. To overcome this problem, the aqueous solutions of large number of hydrotropic agents like sodium benzoate, sodium salicylate, niacinamide, urea, sodium citrate and sodium acetate have been employed to enhance the aqueous solubilities of poorly water-soluble drugs to carry out different analyses. Such analytical methods are ecofriendly and cost effective. These methods should be adopted by various pharmacopoeias, so that, the use of such costly and harmful organic solvents can be minimized.

Keywords: Hydrotropy, thin layer chromatography, UV spectrophotometry, titrimetry, HPLC, organic solvents.