Formulation and evaluation of nalidixic acid-PEG 6000-surfactant systems

Abstract

The anionic surfactant sodium lauryl sulphate was incorporated in different concentrations (1%, 2% and 3%) to solid dispersions of nalidixic acid prepared using PEG-6000 as a carrier by melt-solvent method. The prepared dispersions were characterized by release studies, X-ray diffraction, infrared spectroscopy and thin layer chromatographic analysis. The effect of aging on the release of nalidixic acid was also studied. An almost instant and complete dissolution was obtained for dispersions with 1% w/w sodium lauryl sulphate than pure drug and dispersions without surfactant. The mechanism for increase in the release rate was also investigated. The results were supported by X-ray diffraction studies, which indicated a significant decrease in crystallinity of drug in all the prepared batches. These suggestions were also supported significantly by Infrared spectroscopy and thin layer chromatographic analysis of the samples. The samples were also found to possess adequate stability.