A Systematic Review on Nerve Chemical Warfare Agents

The recent poisoning of Russian opposition figure and critic Alexei Navalny on August 20th , 2020 with a Soviet-era Novichok nerve agent reminded the world of the use of chemical agents, especially nerve agents to eliminate individual targets or for mass destruction. Nerve agents are a class of organophosphorus compounds. Soman, Sarin, Tabun, Cyclosarin, VX are a few examples of nerve agents. Nerve agents affect a person by disrupting the mechanism by which nerve signals are passed in the body. They inhibit the action of acetylcholinesterase enzyme which is responsible for the breakdown of acetylcholine neurotransmitters leading to accumulation of acetylcholine in the body. Nerve agents have a range of chemical effects on the eye, gastro-intestinal (GI) tract, Central nervous system (CNS), Respiratory system, Cardiovascular system and Neurological system. The management of nerve agent poisoning is done by administering Atropine or Pralidoxime chloride or also by administering anticonvulsants like Benzodiazepines or Diazepam. This review presents all such detailed information on this class of chemical Warfare agents. Keywords: Chemical Warfare Weapon, Nerve Agents, Acetylcholinesterase, Toxicity, Instrumentation

Preformulation Studies of Pralidoxime Chloride for Formulation Development of Microspheres

Microspheres are one of the novel drug delivery system which possess several applications and are made up of assorted polymers. Microspheres can be defined as solid, approximately spherical particles ranging in size from 1 to 1000 μm range in diameter having a core of drug and entirely outer layers of polymers as coating material. They are made up of polymeric, waxy or other protective materials i.e. biodegradable synthetic polymer and modified natural products such as starches, gums, proteins, fats and waxes. Preformulation is a group of studies that focus on the physicochemical properties of a new drug candidate that could affect the drug performance and the development of a dosage form. This couldprovide important information for formulation design or support the need for molecular modification. Every drug has intrinsic chemical and physical properties which has been consider before development of pharmaceutical formulation. This property provides the framework for drugs combination with pharmaceutical ingredients in the fabrication of dosage form. Objective of preformulation study is to develop the elegant, stable, effective and safe dosage form by establishing kinetic rate profile, compatibility with the other ingredients and establish Physico-chemical parameter of new drug substances. The purpose of the present study was to systematically investigate some of the important physicochemical properties of pralidoxime chloride for preparation of microspheres. The physicochemical properties such as solubility, pKa, dissolution, melting point, assay development, excipient compatibility etc. of pralidoxime chloride was carried out. Before selection of excipients, the Preformulation study of drug pralidoxime is completed for successful formulation of microspheres. The result of Preformulation studies shows good flow properties, excipient compatibility, solubility efficiency and melting point. From this study we concluded that pralidoximewith HPMC and EC can be used to formulate pralidoxime microspheres for modified release. Keywords: Microspheres, Preformulation, Pralidoxime chloride, Physico-chemical parameter.