DEVELOPMENT AND IN VIVO EVALUATION OF TOLCAPONE CONTROLLED RELEASE TRILAYER MATRIX TABLETS BY GEOMATRIX TECHNOLOGY

Objective: The present study was aimed to develop once-daily controlled release tri-layer matrix tablets of tolcapone, to achieve zero-order drug release for sustained plasma concentration by Geomatrix.Methods: Tolcapone trilayer matrix tablets were prepared by direct compression method and consisted of active middle layer with different grades of hydroxypropyl methylcellulose (HPMC), ethyl cellulose and sodium CMC. Barrier layers were prepared with Eudragit L100-55, guar gum, sodium CMC and DCP.Results: Based on the evaluation parameters, drug dissolution profile and release order kinetics, formulation HF16 was found to be optimized formulation. The developed drug delivery system provided prolonged drug release rates over a period of 24 h. The release profile of the optimized formulation (HF16) was described by the zero-order and best fitted to Higuchi model. FT-IR and DSC studies confirmed that there was no chemical interaction between drug and excipients used in the formulation. The Tmax of the optimized formulation HF16 was significantly different (p<0.05) from that of the marketed product. Low Tmax value for the marketed product (2.02±0.02 h) indicates rapid absorption while the higher Tmax of the optimized formulation (6.00±0.04 h) suggests slower absorption. This delayed absorption of test preparation is most likely due to the sustained release of the drug.Conclusion: The results indicate that the approach used could lead to a successful development of a controlled release formulation of the drug. In vivo studies revealed that the optimized formulation HF16 was shown significant plasma concentration with the controlled release and maintained for 24 h with patient compliance by reducing the dosage frequency when compared with Marketed product in the efficient management of Parkinson's disease.Keywords: Tolcapone, Eudragit L100-55, Geomatrix, Tri-layer matrix tablet, In vivo bioavailability studie

An Efficient Edge Detection Technique for Hazy Images using DCP

Images of outdoor areas are typically degraded in quality by its turbid medium in the nature such as haze, fog and smoke. The absorption and scattering of light on such kind of images effects the quality of the image. The degraded images will loss the contrast and color artifacts from the original image. Edge detection is another challenging issue on such kinds of degraded images. There are several research works are under progress to reduce the haze exists in the image. Although haze removal techniques will reduce the haze present in the image, the results of those techniques were dropped the natural look of the original image as penalty. We proposed an effective way of finding the edges from the hazy images. Firstly, a dark channel prior method is used to eliminate the unwanted haze from the original image. The statistics shows that this method effectively works for the images taken in an outdoor hazy environment. The key observation of this method is that at least one color channel is having a minimum intensity value in a local patch. The results shows that results of this method have a good results compared to other contrast improvement techniques. Secondly we have applied the Sobel edge detection operator to find the edges of the resultant image

A general pressure equation based method for incompressible two-phase flows

We present a fully-explicit, iteration-free, weakly-compressible method to simulate immiscible incompressible two-phase flows. To update pressure, we circumvent the computationally expensive Poisson equation and use the general pressure equation. In addition, the volume-of-fluid approach is used for interface capturing under the operator-split methodology. Our method is fully-explicit and stable with simple local spatial discretization, and hence, it is easy to implement. Several two- and three-dimensional canonical two-phase flows are simulated. The qualitative and quantitative results prove that our method is capable of accurately handling problems involving a range of density and viscosity ratios and surface tension effects

Synthesis and Characterization of Benzoxazinone Derivatives

The present work reports synthesis and characterization of different benzoxazinone derivatives. 2-methyl-7-nitro-4H-3,1-benzoxazin-4-one was prepared by refluxing 4- nitroanthranilic acid with acid anhydride. Derivatives of 2-methyl-7-nitro-4H-3,1-benzoxazin-4-one were synthesized by condensation of it with different anilines. Elemental analysis and NMR spectral studies were used to confirm the formation of compounds

On the Use of Compressed Polyhedral Quadrature Formulas in Embedded Interface Methods

The main idea of this paper is to apply a recent quadrature compression technique to algebraic quadrature formulas on complex polyhedra. The quadrature compression substantially reduces the number of integration points but preserves the accuracy of integration. The compression is easy to achieve since it is entirely based on the fundamental methods of numerical linear algebra. The resulting compressed formulas are applied in an embedded interface method to integrate the weak form of the Navier--Stokes equations. Simulations of flow past stationary and moving interface problems demonstrate that the compressed quadratures improve the efficiency of performing the weak form integration, while preserving accuracy and order of convergence

Synthesis, Characterization and Biological Activity of Quinoline Bound Imidazoles

8-Hydroxyqunoline derivatives were synthesised by treating 5-chloromethyl-8-hydroxy quinoline with imidazole and characterized using NMR and mass spectrometry. 2-mercaptoimidazole derivatives of 8-hydroxy quinoline were also synthesized and characterized. One of the compounds in this series has been tested for dengue activity along with other series of compounds, but did not show any activity against dengue virus

Neuroactive steroids and their role in epilepsy

Neuroactive steroids are the certain steroids that alter neuronal excitability via the cell surface through interaction with certain neurotransmitter receptors. Neuroactive steroids regulate physiological functions of the central nervous system and have possible therapeutic potential in neurological diseases. They have been shown to affect neuronal excitability via their interaction with the ligand-gated ion channel family, such as the GABAA receptor by acting genomically as well as nongenomically. Positive modulators of GABAA receptor have anticonvulsant action as they enhance GABAergic transmission thereby increasing the seizure threshold. By virtue of these properties, neurosteroids appear to be relevant to pathophysiology and pharmacological treatment of many neurological diseases including catamenial epilepsy, stress induced epilepsy, temporal lobe epilepsy, alcohol withdrawal seizures, infantile spasm and status epilepticus. So far, only synthetic neurosteroid, ganaxolone has been tried in treatment of epilepsy and has shown good efficacy and tolerability. But, human data of trials are limited and hence, large double-blinded, placebo-controlled, randomized clinical trials are required before their use. The paper reviews the biosynthesis and GABAA receptor modulation of neurosteroids and their potential role in epilepsy

Renal markers in normal and hypertensive disorders of pregnancy in Indian women:a pilot study

Background:Altered renal function is an essential component of the pathophysiological process in pre-eclampsia. Kidneys play an important role in the turnover of low molecular weight substances such as creatinine, uric acid and cystatin C. The present study was undertaken if these serum markers were characteristically altered in Indian pregnant women.Methods: Serum levels were therefore determined in samples from 69 healthy women at term as well as in 27 samples of patients with Pregnancy induced hypertension (PIH) and in 20 patients with pre-eclampsia (PE).Results: The levels of all three components were significantly higher in pre-eclamptic patients when compared to healthy controls with the mean ± SD being 1.47 ± 0.9 vs. 1.06± 0.2 for cystatin C, 0.95 ±0.2 vs. 0.67 ±0.1 for creatinine and 6.13± 1.8 vs. 4.28 ±1.1 for uric acid respectively. In PIH cystatin C was significantly higher, 1.25 ± 0.9 unlike creatinine, 0.67 ±0.14 and uric acid, 4.30 ±1.0. Receiver operating characteristic (ROC) plots demonstrated that the diagnostic accuracy of serum creatinine was superior to serum uric acid and serum cystatin C and serum uric acid was better than serum cystatin C.Conclusion:The maternal serum cystatin C, creatinine and uric acid were all significantly elevated at the end of pregnancy in pre-eclampsia compared to those of healthy pregnant women. If this rise in the above markers during early pregnancy could predict the onset of PIH/PE, needs to be investigated.