FORMULATION AND EVALUATION OF GASTRORETENTIVE FLOATING BIOADHESIVE TABLETS OF HYDROCHLORTHIAZIDE

Objective: Floating bioadhesive tablets of hydrochlorothiazide were developed to prolong gastric residence time leading to an increase in drugbioavailability where here a combination of floating and bioadhesion mechanism is combined.Methods: Tablets are prepared by direct compression technique using polymers xanthan gum, carbopol 974 P, HPMC K15M, HPMC K100M, magnesiumStearate USP-NF (Avicel PH 102), microcrystalline cellulose Ph 102, Talc, and sodium bicarbonate.Results: Tablets were evaluated for their physical characteristics, namely, hardness, thickness, friability and weight variation, drug content, andfloating properties. The best formulation subjected for kinetic treatment, i.e., zero order, first order, peppas, Higuchi, and Hixon-crowel. The R valuesare 0.9366, 0.9364, 0.9680, 0.9974, and 0.9283, respectively.Conclusion: Optimized formulae F4 containing polymers HPMC K4M and CARBOPOL 974 P showed more bioadhesion with a controlled release over12 hrs. Therefore, formulation F4 identified as a successful formulation for the development of floating bioadhesive tablets.Â

A stochastic model to estimate the expected time to seroconversion – threshold as sum of two components

            The spread of the HIV infection has created an pandemic situation all over the world. It has become necessary to have the combined efforts of medical personnel, social workers and mathematicians and statisticians to study the different aspects of this infection and its spread. One of the interesting aspects of  study is to estimate the likely time at which an infected person becomes seropositive. It is in this connection the antigenic diversity threshold is considered. The antigenic diversity threshold is a particular level of the antigenic diversity of the invading antigen beyond which the human immune system breaks down and a person becomes seropositive. In this paper the expected time to seroconversion is derived under the assumption that the antigenic diversity threshold comprises of two components namely the natural antigenic diversity threshold level of human immune system and the threshold  component due to use of ART. Numerical illustration is also provided

Bio-Analytical Method Development of Repaglinide Drug Delivery Systems

A sensitive, specific and rapid high-performance liquid chromatography-ultraviolet spectroscopy method was developed and successfully validated to estimate the repaglinide in rabbit plasma. The solvent extraction method was used for  repaglinide from serum by using ethyl acetate and 0.1N HCl. The mobile phase consists of acetonitrile: phosphate buffer pH 4.0 at 60:40 %v/v with 1% triethylamine at flow rate of 0.8ml/min and at fixed wavelength of 254nm. On ten minutes of run time, repaglinide was retention at 7.4min. The extraction efficiency 95% for repaglinide. The intra-day and inter-day precision was in the terms of %RSD less than 1.76%. The developed method was validated and proposed method is useful for pharmacokinetics studies.  Keywords: Anti-diabetics, HPLC,Methanol,Phosphate buffer, Repaglinid

Low cost microscopy for three dimensional imaging using digital inline holographic principle

Optical microscopy is reached a new level in terms of resolution, 3 - D imaging capability, flexibility of imaging different samples which increase imaging complexity and the cost.. Though established labs can afford high - end microscopes, it remains a concern in rural areas where clinics and patients cannot afford much. Semi - portable microscopy based on inline holographic setup is demonstrated where depth information as 3rd dimension can also be accessed. This setup contains only light emitting diode (LED), pinhole and charge coup led device (CCD) camera. Since laser source gives rise to speckle noise and it is also cost constraint for developing a low cost microscopy, thus it is replaced with incoherent LED source. This setup is also known as ‘lensless holography’ because there is no use of lens for imaging. In conventional inline holographic setup the sample is placed closed to the pinhole which will restrict field of view (FOV) and diffraction signature of one particle (cell) will overlap w ith other. To avoid overlap of diffractio n signatures and to increase FOV sample was placed close to CCD sensor. To test the working of microscopy agarose microbeads were used. Optimization algorithm is used for reconstruction of object field from recorded hologram.. Thus both amplitude as well a s the phase images of the microbeads is reconstructed. Instead of using microscopic objective to focus sample, autofocus algorithm is used to calculate the focused plan

Enhancement of security and handling the inconspicuousness in IoT using a simple size extensible blockchain

Blockchain technology is increasingly used worldwide to enhance the performance and profit of any environment through its defining characteristics, such as security, auditability, immutability, and inconspicuousness. Owing to these characteristics, the blockchain can be used in various non-financial operations of some domains, such as the Internet of Things (IoT) and distributed computing. However, implementing blockchain technology in IoT is not always a feasible solution because blockchain deployment is costly, it has limited extensibility and provides irregular bandwidth and latency. In this regard, a simple size extensible (SSE) blockchain has been proposed to provide an optimal solution for IoT environments by satisfying the needs of the IoT environment as well as ensuring end-to-end security. The implementation of the proposed blockchain develops an overlay network to obtain a distributed environment where the blockchain is handled by the resources present therein. Two novel algorithms were introduced into the proposed system to minimize the irregularity and latency on one hand, and to maximize the throughput of the system on the other. The shared-time depending agreement algorithm (STD) minimizes the irregularity in the extraction operation and latency. The other, the shared throughput administration algorithm (STA) justifies the overall collection of the transmission load in the network and maintains the performance of the blockchain. The proposed system was applied to smart home IoT appliances to test the performance of the proposed system. The experimental results show that the proposed blockchain system minimizes nearly 70% of the data irregularity, latency, and furthermore, 30% of the blockchain extensibility is maximized as compared to the existing systems

Quantitative imaging of yeast cells using transport of intensity equation

In biology most microscopy specimens, in particular living cells are transparent. In cell imaging, it is hard to create an image of a cell which is transparent with a very small refractive index change with respect to the surrounding media. Various techniques like addition of staining and contrast agents, markers have been applied in the past for creating contrast. Many of the staining agents or markers are not applicable to live cell imaging as they are toxic. In this paper, we report theoretical and experimental results from quantitative phase imaging of yeast cells with a commercial bright field microscope. We reconstruct the phase of cells non-interferometrically based on the transport of intensity equations (TIE). This technique estimates the axial derivative from positive through-focus intensity measurements. This technique allows phase imaging using a regular microscope with white light illumination. We demonstrate nano-metric depth sensitivity in imaging live yeast cells using this technique. Experimental results will be shown in the paper demonstrating the capability of the technique in 3-D volume estimation of living cells. This real-time imaging technique would be highly promising in real-time digital pathology applications, screening of pathogens and staging of diseases like malaria as it does not need any preprocessing of samples

Rational Design of Photoelectrodes for the Fully Integrated Polymer Electrode Membrane–Photoelectrochemical Water-Splitting System: A Case Study of Bismuth Vanadate

Photoelectrochemical (PEC) reactors based on polymer electrolyte membrane (PEM) electrolyzers are an attractive alternative to improve scalability compared to conventional monolithic devices. To introduce narrow band gap photoabsorbers such as BiVO4 in PEM-PEC system requires cost-effective and scalable deposition techniques beyond those previously demonstrated on monolithic FTO-coated glass substrates, followed by the preparation of membrane electrode assemblies. Herein, we address the significant challenges in coating narrow band gap metal-oxides on porous substrates as suitable photoelectrodes for the PEM-PEC configuration. In particular, we demonstrate the deposition and integration of W-doped BiVO4 on porous conductive substrates by a simple, cost-effective, and scalable deposition based on the SILAR (successive ionic layer adsorption and reaction) technique. The resultant W-doped BiVO4 photoanode exhibits a photocurrent density of 2.1 mA·cm–2, @1.23V vs RHE, the highest reported so far for the BiVO4 on any porous substrates. Furthermore, we integrated the BiVO4 on the PEM-PEC reactor to demonstrate the solar hydrogen production from ambient air with humidity as the only water source, retaining 1.55 mA·cm–2, @1.23V vs RHE. The concept provides insights into the features necessary for the successful development of materials suitable for the PEM-PEC tandem configuration reactors and the gas-phase operation of the reactor, which is a promising approach for low-cost, large-scale solar hydrogen production.</p