Abstract:: Carbon nanotubes are nano sized cylindrical chicken wire like structures made of carbon atoms. Carbon nanotubes have applications in electronics, energy storage, electromagnetic devices, environmental remediation and in medicine as well. The biomedical applications of carbon nanotubes can be owed to features like low toxicity, non-immunogenicity, high in vivo stability and rapid cell entry etc. Carbon nanotubes have great prospect in the treatment of diseases through diagnostic as well as therapeutic approaches. These nanostructures are interesting carriers for delivery and translocation of therapeutic molecules e.g. proteins, peptides, nucleic acids, drugs etc. to various organs like brain, lungs, liver, pancreas etc. Commonly used methods to synthesize carbon nanotubes are arc discharge, chemical vapor deposition, pyrolysis, laser ablation etc. These methods have many disadvantages such as operation at high temperature, use of chemical catalysts, prolonged synthesis time and inclusion of toxic metallic particles in the final product requiring additional purification processes. In order to avoid these setbacks various green chemistry based synthetic methods have been devised e.g. those involving interfacial polymerization, supercritical carbon dioxide drying, plant extract assisted synthesis, water assisted synthesis etc. This review will provide a thorough outlook of the eco-friendly synthesis of carbon nanotubes reported in literature and their biomedical applications. Besides, the most commonly used spectroscopic techniques used for the characterization of carbon nanotubes are also discussed.

Herein, we report a novel, accurate and cost-effective validated analytical method for the quantification of losartan potassium and its active metabolite, EXP 3174, in rabbit plasma by reversed-phase high-performance liquid chromatography. Valsartan was used as an internal standard. The method was validated as per International Conference on Harmonization guidelines. The analytes were extracted in rabbit plasma using liquid-liquid extraction technique and analyzed at 247 nm after separation through a reverse-phase C 18 column. The isocratic mobile phase used is a mixture of acetonitrile, water and glacial acetic acid in the ratio of 60:40:1 v/v/v maintained at pH 3.4.All calibration curves showed a good linear relationship (r > 0.995) within the test range. Precision was evaluated by intra-and interday tests with RSDs <1.91% and accuracy showed validated recoveries of 86.20-101.11%. Based on our results, the developed method features good quantification parameters and can serve as an effective quality control method for the standardization of drugs.