Development and validation of HPLC method for simultaneous estimation of piperine and guggulsterones in compound Unani formulation (tablets) and a nanoreservoir system

An attempt has been made to develop and validate a simultaneous HPLC method for novel approach of drug release via oil‐in‐water (o/w) nanoemulsion formulation and Habb‐e‐Khardal Unani tablet containing piperine and guggul sterones E and Z as main ingredients. Nanoemulsion was prepared by titration method using sefsol‐218 as an oily phase, cremophor‐EL as a surfactant, transcutol as a co‐surfactant and distilled water as an aqueous phase. The formulation was optimized on the basis of thermodynamic stability and dispersibilty test. The nanoformulation was evaluated for particle size, surface morphology, electrical conductivity and viscosity determination. The in vitro dissolution was carried out by dialysis bag method. Drugs were quantified using an HPLC method developed in‐house with a C₁₈ column as stationary phase and acetonitrile and water as mobile phase at λ_max of 240 nm. The optimized formulation showed higher drug release, lower droplet size and less viscosity as compared with the conventional Habb‐e‐Khardal Unani tablet. The present study illustrated the potential of nanoemulsion dosage form in improving biopharmaceutic performance of piperine and guggul sterone. The HPLC method was also found to be quite sufficient for the routine quality control of formulations containing piperine and guggul sterone E and Z as ingredients and also for in vitro drug release studies. Copyright © 2011 John Wiley & Sons, Ltd.     

Plumbagin Alleviates Intracerebroventricular-Quinolinic Acid Induced Depression-like Behavior and Memory Deficits in Wistar Rats

Plumbagin, a hydroxy-1,4-naphthoquinone, confers neuroprotection via antioxidant and anti-inflammatory properties. The present study aimed to assess the effect of plumbagin on behavioral and memory deficits induced by intrahippocampal administration of Quinolinic acid (QA) in male Wistar rats and reveal the associated mechanisms. QA (300 nM/4 μL in Normal saline) was administered i.c.v. in the hippocampus. QA administration caused depression-like behavior (forced swim test and tail suspension tests), anxiety-like behavior (open field test and elevated plus maze), and elevated anhedonia behavior (sucrose preference test). Furthermore, oxidative–nitrosative stress (increased nitrite content and lipid peroxidation with reduction of GSH), inflammation (increased IL-1β), cholinergic dysfunction, and mitochondrial complex (I, II, and IV) dysfunction were observed in the hippocampus region of QA-treated rats as compared to normal controls. Plumbagin (10 and 20 mg/kg; p.o.) treatment for 21 days significantly ameliorated behavioral and memory deficits in QA-administered rats. Moreover, plumbagin treatment restored the GSH level and reduced the MDA and nitrite level in the hippocampus. Furthermore, QA-induced cholinergic dysfunction and mitochondrial impairment were found to be ameliorated by plumbagin treatment. In conclusion, our results suggested that plumbagin offers a neuroprotective potential that could serve as a promising pharmacological approach to mitigate neurobehavioral changes associated with neurodegeneration.     

Extreme statistics in Raman fiber amplifiers: From analytical description to experiments

In this work, we investigate the emergence of rare and intense events during the Raman fiber amplification of a continuous wave. We highlight how dispersive properties and pump depletion can strongly influence the statistical properties of the amplified signal and its optical spectrum. Under certain conditions, the probability density functions of the amplified signal are calculated analytically and compared with the results of the numerical simulations. The conclusions are qualitatively validated by experiments carried out at telecommunication wavelengths.     

Facile synthesis of new imidazoles from direct reaction of 2,3‐diamino‐1,4‐naphthoquinone with aldehydes

New imidazoles were easily prepared from 2,3‐diamino‐1,4‐naphthoquinone and stoichiometric quantities of the appropriate aldehydes in dimethyl sulfoxide as a solvent. The reaction proceeded for few hours. The procedure can be generalized to different classes of aldehydes. 2‐Methyl‐1H‐naphtho[2,3‐d]imidazole‐4,9‐dione was also obtained in good yield during refluxing of 2,3‐diaminonaphthoquinone in acetic acid. The structure of the newly synthesized imidazoles was extensively investigated using NMR experiments. J. Heterocyclic Chem., (2011).     

Complementary-reference and complementary-scene for real-time fingerprint verification using joint transform correlator

In this paper, a new configuration for the input joint images in the joint transform correlator is proposed for fast real-time binary characters and fingerprints verification. In the proposed scheme, the input joint image has a complementary-reference image and a complementary target image in addition to the reference and the target images. We use the cross-correlation peak value between the reference and the complementary target image and the cross-correlation peak value between the complementary reference and the target images as the criteria to perform the recognition of the target in the input scene. It is shown that these two cross-correlation peak values will be zero if and only if the input target matches the reference image. One advantage of using the proposed scheme is the elimination of the usual and necessary time-consuming normalization of the input images in the general correlation-based matching processes. Another advantage of the proposed scheme is the insensitive to light-sources intensity fluctuations that usually limits the matched-based recognition approaches. The scheme is employed to verify binary characters and fingerprints images; further, it is employed to verify occluded fingerprints target images on one hand, and to determine if a specific part or pattern exists in the target fingerprint image on the other hand.     

Stereoselective synthesis of beta-substituted phenylalanine-beta-phenylisoserine-derived tripeptides using N-cinnamoyl-L-proline as template: synthesis of structural analogues of HIV protease inhibitors

N-Cinnamoyl-L-proline can be used as a template on which beta-substituted phenylalanine and beta-phenylisoserine residues can be synthesized leading to tripeptide derivatives as structural analogues of HIV protease inhibitors.