Exploring the Use of Sodium Benzoate as Hydrotrope for the Estimation of Lornoxicam in their Marketed Formulation

Abstract

Increasing the aqueous solubility of insoluble drugs is of major importance for the estimation by spectrophotometric technique. Various techniques have been employed to enhance the aqueous solubility of poorly water soluble drugs. Hydrotropic solubilization is one of them. In the present study, sodium benzoate was chosen as hydrotrope to enhance the solubility of Lornoxicam for its spectrophotometric estimation in their marketed formulation. Preliminary solubility of Lornoxicam, spectral study, method development and its validation was done as per ICH guidelines. Solubility study of Lornoxicam displayed a signifi cant increment in the solubility due to 10% solution of sodium benzoate which will be suffi cient to extract the drug from its dosage form. The sample solution has shown the λ max at 376 nm and obeys the lambert beer law in the concentration range of 5-25 μg/ml with a correlation coeffi cient of 0.999. The accuracy of the method was proved by recovery study with mean recovery of 99.87. Precision study also shows no signifi cant deviation from the mean value. A limit of detection and limit of quantitation result indicates the sensitivity of the method with the values 1.02 μg/ml and 3.39 μg/ml simultaneously. Hence, the methodology can be used safely and effectively for the routine estimation of Lornoxicam in the bulk drug and marketed formulation. Key words: Hydrotropic solubilization, sodium benzoate, spectrophotometric estimation, validation.