Design and implementation of low power FPGA-based optimal multiband filter with Spline function for denoising ECG signals.

This article presents the design and implementation of a low power FPGA-based optimal multiband filter with Spline function for denoising ECG signals. The proposed multiband filter design utilizes least mean square algorithm to determine the optimal filter coefficients for multiple frequency bands, while the Spline function is used to interpolate the filter coefficients within each band to achieve a smooth transition between adjacent bands. The experimental work is carried out with ECGID database and it shows that the proposed filter outperforms in terms of benchmark performance matrices SNR, MSE, CC and PRD. The filter is implemented on a low power FPGA platform, which allows for real-time processing of ECG signals with low power consumption. The experimental results are analyzed and compared for different architecture using the MATLAB and XILINX VIVADO tools. The serial architecture of proposed filter design is implemented on Artix 7 (XC7A35T) EDGE Board, utilizing 1932 LUT, 5299 FF, 1 DSP block and 0.158 W on-chip power. The experimental results indicate that the proposed filter design approach is efficient, effective, and suitable for implementation in compact biomedical devices.

Targeting posterior eye infections with colloidal carriers: The case of Ganciclovir.

The ocular system, unlike any other human body organ, is a system in which foreign bodies appear quite defenceless in front of the eye. Several infections of the ocular system occur due to various opportunistic conditions. Cytomegalovirus (CMV) is one of the opportunivores that causes several posterior eye infections. Ganciclovir (GCV),9-(2-hydroxy-1-(hydroxymethyl) ethoxymethyl), is aguanine-antiviral agent primarily used to treat CMV diseases. However, the major challenge is of lower bioavailability. Hence, GCV must be dosed repeatedly to enhance drug absorption. but this causes side effects like neutropenia and bone marrow suppression. So, formulators have used alternative formulation strategies such as prodrug formulation and colloidal drug delivery systems. In the prodrug strategy, they attempted to bind various compounds into the parent drug to increase the permeability and bioavailability of GCV. In colloidal drug delivery systems, mucoadhesive microspheres, nanoparticles, Niosome and liposome were employed to extend the drug residence time at the application site. This paper discusses several colloidal carriers combined with GCV to treat opportunistic CMV infection in the posterior ocular system. It reviews the limitations of conventional ocular therapy and explores various novel formulation approaches to improve the ocular bioavailability of GCV in the posterior chamber of the eye.

Melt Dispersion Adsorbed onto Porous Carriers: An Effective Method to Enhance the Dissolution and Flow Properties of Raloxifene Hydrochloride.

The objective of the present investigation is to enhance the dissolution and flow properties of raloxifene hydrochloride (RXH), a biopharmaceutical classification system class II drug. Melt dispersion of RXH with polyethylene glycol (PEG) 6000 was prepared by the fusion method. The melt dispersion was then adsorbed onto a porous adsorbent, Neusilin, by the melt adsorption method. Response surface methodology was employed to establish the design space for formulation variables such as the ratio of RXH to PEG 6000 in melt dispersion and amount of porous adsorbent to melt dispersion. Differential scanning calorimetry, scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and accelerated stability techniques were utilized to characterize formulations. Negative Gibbs free energy values indicated spontaneous solubilization of RXH in PEG 6000. The time required for 80% of drug release from optimized formulation was <20 min compared with plain RXH. Accelerated stability studies confirmed the stabilization of amorphous melt dispersion in nanopores (nanoconfinement) of inorganic silicate Neusilin. Melt dispersion, adsorbed on porous carriers, is a promising technique to improve the dissolution characteristic as well as flow properties of drug molecules.

Stability Indicating Liquid Chromatographic Method for Simultaneous Determination of Aspirin and Omeprazole.

BACKGROUND: Aspirin combination is prescribed for its thrombolytic activity where gastric ulceration is the major side effect of aspirin which can be prevented by combining it with proton pump inhibitor omeprazole. Present study describes development of analytical method for the estimation of aspirin and omeprazole in combination. OBJECTIVE: The aim of the present study was to develop and validate chromatographic method for simultaneous analysis of aspirin and omeprazole. METHODS: Isocratic, reversed phase stability indicating liquid chromatographic method was developed for the simultaneous determination of Aspirin and Omeprazole in combination. The separation was achieved on a Thermo Scientific Hypersil ODS (250 x 4.6 mm, 5 µm) column, kept at ambient temperature, using acetonitrile: methanol: 0.05 M phosphate buffer (40:5:55; pH 4 adjusted with 0.1% tri ethyl amine) as a mobile phase at a flow rate of 1 mL/min and UV detection was performed at 225 nm. RESULTS: The retention time was found to be 3.9 min for aspirin and 5.3 min for omeprazole. The method was observed to be linear in the range of 2 - 80 µg/mL for aspirin and 1 - 40 µg/mL for omeprazole, respectively. The proposed method was validated as per ICH guidelines Q2 (R1). The developed RP- HPLC method was successfully applied for the simultaneous estimation of aspirin and omeprazole in the presence of degradation products of both the drugs. CONCLUSION: The present study describes liquid chromatographic method for the estimation of aspirin and omeprzole in combination. The method can be used for the analysis of stability samples and routine quality control samples.

Possible anti-depressant effect of efavirenz and pro-depressive-like effect of voriconazole in specified doses in various experimental models of depression in mice.

BACKGROUND: Reports from experimental and clinical studies have indicated the possible relation between cholesterol and depression. Efavirenz (EFV) and Voriconazole (VRC) have been reported to affect cholesterol-24S-hydroxylase enzyme. The objective of the present study was to evaluate the effect of EFV and VRC in experimental models of depression in mice. METHODS: There was a measurement of immobility time in forced swim test and tail suspension test in which mice were previously subjected to the treatment of EFV (0.09mg/kg, orally (po)) and VRC (75mg/kg, intraperitoneally (ip)) separately for 14days. Sucrose intake was measured during stress schedule of 21days in chronic mild stress model in which mice were subjected to above mentioned drug treatment for last 14days. There was an estimation of serum total cholesterol and brain serotonin levels on day 21. RESULTS: The results indicated that mice treated with EFV showed a significant decrease in the immobility time and increase in sucrose intake with decrease in serum total cholesterol. Mice treated with VRC showed a significant increase in the immobility time and decrease in the sucrose intake with increase in serum total cholesterol. There was a significant increase and decrease in brain serotonin levels in mice treated with EFV and VRC respectively. CONCLUSION: The results of the present study indicates the possible anti-depressant effect of EFV and pro-depressive-like effect of VRC in specified doses in mice, raising the possibility that stimulation but not inhibition of cholesterol-24S-hydroxylase may be important in the treatment of depression.

Characterization of natural polymers from jackfruit pulp, calendula flowers and tara seeds as mucoadhesive and controlled release components in buccal tablets.

Identification and physiochemical parameters such as solubility, loss on drying, viscosity, pH, swelling index, starch and gum constituents were determined in natural polymers and showed satisfactory results. Spectral studies established the compatibility of natural polymers. The drug release kinetics in preliminary trial batches showed that tablets containing natural mucilages and gum showed a prolonged drug release comparable to Carbopol 974P and Methocel K4M. Also, all tablets showed a satisfactory drug permeability flux. Acute toxicity studies confirmed the safety of natural polymers. Using response surface method supported by 23 factorial design, the optimized buccoadhesive tablets (C1) with drug release at 8h (R8h, %) of 53.48±0.048% showed controlled release over ≥8h and followed the Korsmeyer-Peppas model with anomalous (non-Fickian) diffusion mechanism. Mucoadhesive strength was found to be 42.71±0.49g. Comparative dissolution study between prepared and marketed formulation showed that there was no significant difference in drug release profile having similarity factor 82.97. In vivo study for optimized formulation of the buccoadhesive tablets showed the better absolute bioavailability (71.26%) against the oral solution (51.22%). Histological study confirmed non-irritant nature and stability study indicated stability of the formulation.

Effects of piperine, cinnamic acid and gallic acid on rosuvastatin pharmacokinetics in rats.

The purpose of this study was to investigate the potential pharmacokinetic interactions with natural products (such as piperine (PIP), gallic acid (GA) and cinnamic acid (CA)) and rosuvastatin (RSV) (a specific breast cancer resistance protein, BCRP substrate) in rats. In Caco2 cells, the polarized transport of RSV was effectively inhibited by PIP, CA and GA at concentration of 50 µM. After per oral (p.o.) coadministration of PIP, CA and GA (10 mg/kg) significantly increased intravenous exposure (AUC(last)) of RSV (1 mg/kg) by 73.5%, 62.9% and 53.3% (p < 0.05), respectively than alone group (control). Compared with the control (alone) group, p.o. coadministration of PIP, CA and GA (10 mg/kg) significantly increased the oral exposure (AUC(last)) of RSV (5 mg/kg) by 2.0-fold, 1.83-fold (p < 0.05) and 2.34 -fold (p < 0.05), respectively. Moreover, the cumulative biliary excretion of RSV (5 mg/kg, p.o.) was significantly decreased by 53.3, 33.4 and 39.2% at the end of 8 h after p.o. co-administration of PIP, CA and GA (10 mg/kg), respectively. Taken together, these results indicate that the natural products such as PIP, CA and GA significantly inhibit RSV transport in to bile and increased the plasma exposure (AUC(last)) of RSV.

Isolation and characterization of jackfruit mucilage and its comparative evaluation as a mucoadhesive and controlled release component in buccal tablets.

BACKGROUND: The purpose of the present research work was to extract jackfruit mucilage, use it as a mucoadhesive agent, and to develop extended release buccoadhesive tablets with an intention to avoid hepatic first-pass metabolism, by enhancing residence time in the buccal cavity. MATERIALS AND METHODS: The mucilage was isolated from the jackfruit pulp by the aqueous extraction method and characterized for various physiochemical parameters as well as for its adhesive properties. Three batches of tablets were prepared (wet granulation method) and evaluated containing three mucoadhesive components: Methocel K4M, Carbopol 974P, and isolated jackfruit mucilage using chlorpheniramine maleate (CPM) as a model drug and changing the proportion of the mucoadhesive component (1:2:3), resulting in nine different formulations. RESULTS: The results of the study indicate that the isolated mucilage had good physicochemical and morphological characteristics, granules and tablets conformed to the Pharmacopoeial specifications, and in vitro release studies showed the sustained action of drug with increasing concentration of the isolated natural mucoadhesive agent in the formulations. Permeability studies indicated that changing the mucoadhesive component, permeability behavior was not statistically different (P > 0.05). FTIR and UV spectroscopy studies between mucilage and CPM suggested the absence of a chemical interaction between CPM and jackfruit mucilage. CONCLUSION: The developed mucoadhesive tablets for buccal administration containing natural mucilage (MF3) have a potential for the sustained action of drug release. Thus, mucoadhesive tablets for controlled release were successfully developed using natural jackfruit mucilage.

Formulation, evaluation and optimization of sustained release matrix tablets of captopril.

Sustained release matrix tablet is a delivery system by which the drug can be delivered at a controlled rate for long period of time. The present study aims at formulation, evaluation and optimization of captopril matrix tablets. A 3(2) full factorial design was adopted and all 9 batches were prepared by wet granulation method. Prepared granules and tablets were evaluated for precompression and postcompression characteristics respectively. Check point analysis was applied to the observations and the formula of the tablet was optimized. Optimized formula, F6 showed zero order drug release kinetics for the time period of 24 hours i.e. 17.55% release at the end of 2 hours, 53.4% release at the end of 12 hours and 100.24% release at the end of 24 hours. The results revealed that concentration of matrix forming agent and solution of granulating agent significantly affected in vitro drug release profile.

Split calibration curve: an approach to avoid repeat analysis of the samples exceeding ULOQ.

BACKGROUND: The current practice of using calibration curves with narrow concentration ranges during bioanalysis of new chemical entities has some limitations and is time consuming. In the present study we describe a split calibration curve approach, where sample dilution and repeat analysis can be avoided without compromising the quality and integrity of the data obtained. RESULTS: A split calibration curve approach is employed to determine the drug concentration in plasma samples with accuracy and precision over a wide dynamic range of approximately 0.6 to 15,000 ng/ml for dapsone and approximately 1 to 25,000 ng/ml for cyclophosphamide and glipizide. A wide dynamic range of concentrations for these three compounds was used in the current study to construct split calibration curves and was successfully validated for sample analysis in a single run. CONCLUSION: Using this method, repeat analysis of samples can be avoided. This is useful for the bioanalysis of toxicokinetic studies with wide dose ranges and studies where the sample volume is limited.

Validated HPTLC method for quantitative determination of gallic acid in stem bark of Myrica esculenta Buch.-Ham. ex D. Don, myricaceae.

A simple, rapid, and precise HPTLC method was developed for quantitative estimation of gallic acid in stem bark of Myrica esculenta, family Myricaceae. Separation was performed on silica gel 60F254 HPTLC plates using toluene-ethyl acetate-formic acid-methanol (3 + 3 + 0.6 + 0.4, v/v/v/v) mobile phase for separation of the extracted components. The determination was carried out in the UV densitometric absorbance-reflection mode at 280 nm. The amount of gallic acid in free and combined form in the stem bark powder was found to be 0.276 and 0.541%, respectively, on a dry weight basis. The method was validated in terms of linearity, accuracy, precision, and specificity according to International Conference on Harmonization guidelines. Gallic acid response was found to be linear over a broad concentration range of 0.4-2.0 microg/band. LOD and LOQ were 0.103 and 0.312 microg/spot, respectively. The developed method is capable of quantifying amounts of gallic acid in stem bark powder of M. esculenta.

Development of microemulsion for solubility enhancement of clopidogrel.

Clopidogrel, an inhibitor of platelet aggregation, selectively inhibits the binding of adenosine diphosphate (ADP) to its platelet receptor and the subsequent ADP-mediated activation of the glycoprotein GPIIb/IIIa complex, thereby inhibiting platelet aggregation. Oral bioavailability of clopidogrel is very low (less than 50%), due to its poor water solubility. The aim of this investigation was to design and develop a microemulsion formulation of clopidogrel for enhancing its solubility, and hence its oral bioavailability. For this purpose, initially, solubility of clopidogrel was determined in various vehicles. Next, pseudo-ternary phase diagrams were constructed to identify the microemulsion existing zone. Solubility study was also performed for optimization of formulation. The optimized microemulsion formulation was characterized for its transparency, droplet size, zeta potential, viscosity, conductivity, % assay, and phase separation study. Particle size and zeta potential of the optimized microemulsion formulation were found to be 12.3 nm, and -6.34 mV, respectively. The viscosity and conductivity data indicated that the microemulsion was of the o/w type. Solubility of clopidogrel was successfully enhanced by 80.66 times, via capmul microemulsion, compared with distilled water (pH = 7.4). 75.53% and 71.2 % of the drug content were found to be released within 9 h in the in-vitro and ex-vivo studies, respectively. Hence, by formulating into microemulsion, the solubility of clopidogrel was found to be significantly enhanced.

Spectrophotometric Determination of Cefetamet Pivoxil Hydrochloride and Pitavastatin Calcium in Tablet Dosage form.

Two simple, rapid, specific and accurate analytical methods for the estimation of cefetamet pivoxil hydrochloride and pitavastatin calcium in bulk drug and in their tablet formulations are described. These methods are based on difference spectrophotometry, wherein the measurement is done at maximum 221 nm and minimum 275 nm for cefetamet whereas at maximum 240 nm and minimum 259 nm for pitavastatin. The Beer's law was obeyed in the concentration range of 1-35 µg/ml and 1-25 µg/ml and the molar absorptivities were 1.3×10(4) lit mol(-1) cm(-1) and 2.4×10(4) lit mol(-1) cm(-1) for cefetamet pivoxil hydrochloride and pitavastatin calcium, respectively. The proposed methods were validated and successfully applied to the estimation of drugs in tablet formulations.