Vilasrao J. Kadam

The methanolic extract of Punica granatum (PUG), Glycyrrhiza glabra (GLA) and their combination (PUG-GLA) were evaluated for their wound healing activity using excision wound model in rats. Rats treated with PUG-GLA showed higher rate of wound contraction, significant decrease in epithelization period and significant increase in hydroxyproline content of granulation tissue when compared with the controls. The histological examination of treated wounds showed that the original tissue regeneration was much greater in PUG-GLA, with increase in the restoration of collagen fibers, fibroblasts, blood vessel formation and hair follicle regeneration.

The aim of the present study was to optimize carbon tetrachloride (CCl4­) induced hepatotoxicity in the rat with respect to dose and time course. Female Sprague Dawley rats, weighing 150-200g were used in the present study. Hepatotoxicity was evaluated by measuring the activity of serum enzymes, alanine transaminase [ALT], aspartate transaminase [AST], alkaline phosphatase [ALP] and total bilirubin [TBIL] level. Experimental hepatotoxicity was induced by administering 1, 1.5, 2 ml/kg CCl4 (dissolved in an equal volume of olive oil) intraperitonially (i.p) and observed for enzyme levels at time intervals of 0, 2, 24, 48 hours after CCl4­ challenge. Result values are analyzed by One way ANOVA followed by Dunnett’s test. 1 ml/kg CCl4 increased the levels of serum enzymes that reached a peak after 24 hr and showed moderate hepatitis which is ideal for development of acute hepatotoxicity. It is possible to select optimum dose of CCl4 to induce hepatotoxicity by single i.p injection in order to study hepatoprotective activity of herb without causing death of animals. Keywords- Carbon tetrachloride, Dose, Hepatotoxicity, Time course

Quetiapine fumarate is a new generation atypical antipsychotic drug indicated for the treatment of schizophrenia and related psychoses. Various analytical methods used for the estimation of quetiapine has been reviewed in this paper. These include Ultraviolet spectrometry, High performance thin layer chromatography, High performance liquid chromatography, Potentiometry, Polarography, Ion titrimetry and Voltametry to determine the amount of quetiapine fumarate in bulk drugs, pharmaceutical formulations and biological fluids. Stability indicating and impurity profiling methods for quetiapine are also described. These analytical methods can be used for qualitative and quantitative estimation of quetiapine and / or its related impurities or degradants in bulk, formulation and biological fluids.

  Targeted drug delivery to the colon is more desirable for local treatment of a variety of bowel diseases and systemic delivery of protein and peptide drugs. Targeting depends on exploiting a unique feature of specific site and protecting the drug until it reaches to the site. To achieve the delivery of intact drugs to the colon, different primary as well as potential novel approaches are used. To achieve the maximum site specific delivery of drugs to colon, combination of two or more approaches are preferred over individual approaches. Because of limited success of primary approaches newly developed approaches are preferred.

  Examination of nature’s favorite molecules revealed that nucleic acids, proteins and polysaccharides are condensation polymers of small subunits stitched together by carbon ± heteroatom bonds. Taking clue from the natures approach, a set of powerful, highly reliable and selective reactions were developed for the rapid synthesis of useful new compounds, an approach called as “click reactions”.  Thus click chemistry is a modular synthetic approach that utilizes the most practical and reliable chemical transformations. Its applications are increasingly found in all aspects of drug discovery, ranging from lead finding through combinatorial chemistry and target-template in situ chemistry, to proteomics and DNA research, using bioconjugation reactions. One of the reactions of click chemistry i.e. copper (I)-catalyzed 1, 2, 3-triazole forming reaction has become the gold standard of click chemistry due to its reliability, specificity and biocompatibility of the reactants. The triazole products are more than just passive linkers; they readily associate with biological targets, through hydrogen bonding and dipole interactions. This review gives a brief overview about some of the advances and applications of these click reactions.

  Bioisosteres are atoms or group of molecules that fit the broadest definition for isosteres. They have chemical and physical similarities thus producing broadly similar biological properties. Many heterocycles, when appropriately substituted exhibits bioisosterism. Bioisosterism represents an approach used by the medicinal chemist for the rational modification of lead compounds into safer and more clinically effective agents. It has significant value in drug design and lead optimization process as it may enhance the desired biological or physical properties of a compound, reduce toxicity and also alter the metabolism of the lead. Bioisosteric replacement is not simple replacement with another isostere but they are firstly analyzed by structural, solubility and electronic parameters to obtain molecules having similar biological activity. Few of the popular examples of the successful use of bioisosteres have been included. The objective of this review is to provide an overview of bioisosteric replacements which can be used for advance drug development.

The purpose of this research work was to prepare an extended release formulation of metoprolol succinate using Ion exchange resin. Metoprolol succinate has short half life of 3-7 hours. So it needs to be administered 3-4 times a day. Hence an extended release preparation is desired. Drug-resin complex (DRC) was obtained by loading metoprolol succinate onto a strong cation exchange resin, Indion 244 in the ratio 1.5:1 using batch method. The molecular properties of the complex were investigated by differential scanning calorimetry, X-ray powder diffraction and Infra red spectroscopy which revealed interaction of drug with resin. To achieve the desired release rate, the DRC was initially treated with an impregnating agent, polyethylene glycol (PEG) 4000 and was further treated with hydrophobic polymer ethyl cellulose. Various formulations of tablets using resinate were prepared to achieve desired drug release profile. The formulations were evaluated for hardness, friability, weight variation, in vitro release and assay using HPLC. Formulation (V) shows optimum results in terms of release profile, which were in accordance with the USP specifications. The in vitro release profile showed that complexation of drug with ion exchange resin and use of hydrophobic polymer matrix could retard the initial burst and extend the release of drug up to 24 hours.