T. Sivakumar

In this study, we formulated and investigated the effects of Temozolomide (TM)/Poly (lactide-co-glycolide) (PLGA) nanoparticles on the behaviour of C6 glioma cells. The nanoparticles were fabricated by the emulsifying solvent evaporation, and they were characterized by using X-Ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that such nanoparticles had a smooth surface and a spherical geometry. Powder X-ray diffraction (XRD) results indicated that TM trapped in the nanoparticles existed in an amorphous or disordered-crystalline status in the polymer matrix. The release profiles of Temozolomide from nanoparticles resulted in biphasic patterns. After an initial burst, a continuous drug release was observed for up to 1 month. Finally, a cytotoxicity test was performed using Glioma C6 cancer cells to investigate the cytotoxicity of Temozolomide delivered from PLGA nanoparticles. It has been found that the cytotoxicity of Temozolomide to Glioma C6 cancer cells is enhanced when TM is delivered from PLGA polymeric carrier and while Temozolomide powder shows activity only up to 12 hours, where as Temozolomide loaded PLGA nanoparticles shows cytotoxicity in much more enhanced way.

This review presents the numerous researches which explore the potential use of polymeric nanoparticles as carriers for a wide range of drugs for therapeutic applications. Because of their versatility and wide range of properties such as better encapsulation, control release and less toxic properties, biodegradable polymeric nanoparticles are being used as novel drug delivery systems. In particular, this class of carrier holds tremendous promise in the areas of targeted drug delivery system.

A reversed phase high-performance liquid chromatographic method was developed and validated for the quantitative determination of two antiviral drugs viz. lopinavir and ritonavir. Chromatography was carried out by gradient  technique on a reversed-phase C18 Column, Phenomenex (250 x 4.6 mm, 5 µ) with mobile phase mixture of Buffer: Acetonitrile (45:55 v/v) was used as a mobile phase and the pH was adjusted into 4.5 by using with O-phosphoric acid, at a flow rate of 1.2 ml/min. The UV range was detected at 240nm for lopinavir and ritonavir respectively. The different analytical performance parameters such as linearity, precision, accuracy, and specificity, limit of detection (LOD) and limit of quantification (LOQ) were determined according to International Conference on Harmonization ICH Q2B guidelines. The linearity of the calibration curves for each analyte in the desired concentration range is good (r2 >0.9). The recovery of the method was between 102.1% and 100.1% for lopinavir and ritonavir respectively. Hence the proposed method is highly sensitive, precise and accurate and it successfully applied for the reliable quantification of API content in the commercial formulations of lopinavir and ritonavir. Key words: Lopinavir, Ritonavir, UV spectrophotometry, RP-HPLC.