Screening, production, and characterization of biologically active secondary metabolite(s) from marine Streptomyces sp. PA9 for antimicrobial, antioxidant, and mosquito larvicidal activity

1319-1326Bioprospecting of actinobacteria from understudied ecosystems is a promising source for extracting novel bioactive metabolites. A study was undertaken to characterize and analyze the bio-efficacy of actinobacterial extract for antimicrobial, larvicidal, and antioxidant activities. Seven morphologically different actinobacterial cultures isolated from mangrove rhizosphere sediment near Parangipettai, South India, were tested for antimicrobial activity. Bioactive metabolites from one potential strain PA9 were produced by submerged fermentation. The selected Streptomyces sp. PA9 was subjected to the production of crude extract for antimicrobial, larvicidal, and antioxidant activity. The actinobacterial compound was characterized by Fourier transform infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC), and gas chromatography–mass spectrometry (GC–MS). The PA9 actinobacterial crude extract showed best antimicrobial activity against clinical bacteria, Salmonella typhi (21.6 ± 0.88 mm) and fungi, Candida albicans (26.6 ± 0.88 mm). The PA9 extract showed significant larvicidal activity against Culex quinquefasciatus with LC50=173.21 µg/ml and r2=0.841. The PA9 extract also exhibited antioxidant activity from DPPH (72%) and nitric oxide free radicals (85%). The characterization of the PA9 extract by FTIR analysis showed the presence of possible functional groups. Active compounds were isolated by HPLC and GC–MS with major and minor peaks observed on the basis of retention time. The bio-efficacy of PA9 has warranted further studies to develop a baseline for the drug development

Validated stability-indicating RP-HPLC method for simultaneous estimation of candesartan and pioglitazone in human plasma

Objective: The focus of this study was to establish a simple, robust, and validated RP-column approach to analyze Candesartan and Pioglitazone in a bilayer tablet dosage form. To broaden patient compliance in conditions such as diabetes and hypertension, a combination of drugs is often prescribed. As a result, a bilayer tablet containing a fixed-dose combination of 8 mg of Candesartan and 15 mg of Pioglitazone was developed. Both drugs were analyzed and chromatographically separated using the liquid chromatography technique. Methodology: waters 2695 with a quaternary pump and Inertsil C18 column mobile phase as buffer: acetonitrile (60:40) and flow rate of 1ml per minute and detection at 220nm was used for performing Chromatography. Results: Internal standard, Candesartan, and Pioglitazone eluted with retention times of 2.208, 2.569, and 3.553 minutes, respectively. There was no interference found between the peaks. With a correlation value of 0.999, the approach is verified across a linear range of 0.5 µg/ml – 20.0µg/ml for Candesartan and 0.08 µg/ml – 3.2 µg/ml for Pioglitazone. 6 samples at LLOQ level were analyzed for accuracy and precision and found to be in limit and all the analytes were stable at 28 °C and  -80 °C in human plasma.&nbsp

Optimization of variance reduction techniques used in EGSnrc Monte Carlo Codes

Monte Carlo (MC) simulations are often used in calculations of radiation transport to enable accurate prediction of radiation-dose, even though the computation is relatively time-consuming. In a typical MC simulation, significant computation time is allocated to following non-important events. To address this issue, variance reduction techniques (VRTs) have been suggested for reducing the statistical variance for the same computation time. Among the available MC simulation codes, electron gamma shower (National Research Council of Canada) (EGSnrc) is a general-purpose coupled electron-photon transport code that also features an even-handed, rich set of VRTs. The most well-known VRTs are the photon splitting, Russian roulette (RR), and photon cross-section enhancement (XCSE) techniques. The objective of this work was to determine the optimal combination of VRTs that increases the simulation speed and the efficiency of simulation, without compromising its accuracy. Selection of VRTs was performed using EGSnrc MC User codes, such as cavity and egs_chamber, for simulating various ion chamber geometries using 6 MV photon beams and 1.25 MeV60Co photon beams. The results show that the combination of XCSE and RR yields the highest efficiency for ion-chamber dose calculations inside a 30 cm × 30 cm × 30 cm water phantom. Hence, properly selecting a different VRT without altering the underlying physics increases the efficiency of MC simulations for ion-chamber dose calculation

Analytical quality by design-based RP-HPLC method for quantification of pioglitazone and candesartan cilexetil in bilayer tablet and its forced degradation studies

Aim: The current project involves developing an RP-HPLC method for simultaneous quantification of Candesartan Cilexetil and Pioglitazone based on analytical quality by design (AQbD). Materials and methods: When analysed in the Design Expert application, the critical method parameters were systematically refined using Central Composite Design and contours were derived for significant variables. A contour plot has been used to discover the technique operable design region that governs response variation, which is then empirically tested. Results: Successful chromatographic separation of title analytes was achieved on kromasil C18 (150 × 4.6 mm, 5 µm) column at 30 °C with mobile phase comprising 60% 20 Mm Potassium dihydrogen orthophosphate and 40% acetonitrile (v/v), isocratic elution pattern, 0.9 mL/min flow rate, and UV detection at 220 nm. The linear model for Candesartan Cilexetil was from 4 to 24 µg/ mL and Pioglitazone at 7.5–45 µg/ mL, respectively. Conclusion: The method met all the ICH Q2 (R1) validation criteria. The current approach aided for analysing simultaneous drugs can be expanded into quantifying drugs in biological matrix predominance with maximum recovery

Formulation of Sodium Alginate Nanospheres Containing Amphotericin B for the Treatment of Systemic Candidiasis

Purpose: The aim of this work was to formulate sodium alginate nanospheres of amphotericin B by controlled gellification method and to evaluate the role of the nanospheres as a "passive carrier" in targeted antifungal therapy. Methods: Sodium alginate nanospheres of amphotericin B were prepared by controlled gellification method, and the particle size analysis was carried out by scanning electron microscopy. The carrier capacity of sodium alginate was evaluated in terms of drug to polymer ratio. In vitro release study was carried out on all drug loaded nanospheres by the dialysis method. Release kinetics of drug from different drug loaded nanospheres was also determined. The in vivo antifungal efficacy of nanospheres bound drug vis-à-vis the free drug was evaluated in candidiasis- induced mice models. Results: Preparation of nanospheres through controlled gellification method yielded particles with a size range of 419.6 ± 0.28 nm. Studies on drug to polymer ratio showed a linear relationship between concentration of drug and drug loading capacity. In vitro release kinetic study revealed that the release of drug from the nanospheres followed Fickian diffusion. In vivo studies showed that the nanospherebound drug produced a higher antifungal efficacy than the free drug. Conclusion: The formulated sodium alginate nanospheres containing amphotericin B was found to have better antifungal activity when compared to the free drug and also yielded sustained in vitro release

Determination and estimation of pharmacokinetic profile of caffeine in form of extract of green tea leaves and its analogy with synthetic form

The aim of the study was to formulate and investigate the pharmacokinetic parameters for the tablets of herbal extract of caffeine with comparison to synthetic formulation. The tablets of the aqueous herbal extract of leaves of Camellia sinensis and synthetic caffeine were formulated by wet granulation technique. The HPLC and HPTLC were applied as analytical tools for estimation of caffeine. The batches of formulation (B1 to B7) were subjected for various pre and post-formulation studies. The pharmacokinetic of the batch B5 was assessed in rabbits, and the results were compared to synthetic batch B7. With the suitable pre and post-formulation results, the B5 showed in vitro release of 90.54% of caffeine at the end of 60 min. The release followed first order kinetics and the plot of Higuchi and Peppas confirms anomalous diffusion as the basic mechanism behind the release. B5 revealed non-significant mean C max, t 1/2, and AUC of 1.88 μg/ml, 5.52 h and 9.67 μg.h/ml respectively compared to B7. The study highlights; no significant difference in the pharmacological effect of caffeine when administered in the form of extract. The administration of herbal extract can further provide the other health benefits lacked by synthetic caffeine

Outcomes of Patients with Atrial Fibrillation Undergoing Percutaneous Coronary Intervention Analysis of National Inpatient Sample

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia with a prevalence of 15% of patients over 80 years. Coronary artery disease co-exists in 20–30% of patients with atrial fibrillation. The need for triple anticoagulation therapy makes the management of these patients challenging following PCI. Methods: Nationwide inpatient sample which is a set of longitudinal hospital inpatient databases was used to evaluate the outcome of patients with AF who underwent PCI. All patients undergoing PCI between 2002 and 2011 were included in the study. Specific ICD-9-CM codes were used to identify the study patients and their outcomes. Results: There were 3,226,405 PCIs during the time period of the study of which 472,609 (14.6%) patients had AF. AF patients were older and predominantly male (60%). The number of PCIs had a declining trend from 2002 to 2011. Age adjusted inpatient mortality was significantly higher in PCI AF group compared to the PCI non-AF group (100.82 ± 9.03 vs 54.07 ± 8.96 per 100,000; P \u3c 0.01). Post PCI predictors of mortality were AF (OR 1.56, CI 1.53–1.59), CKD (OR 1.41, CI 1.37–1.46), PAD (OR 1.20, CI 1.15–1.24), acute myocardial infarction (OR 2.42 CI 2.37–2.46 and cardiogenic shock (OR 13.92 CI 13.60–14.24) P \u3c 0.001. Conclusion: AF is common in patients undergoing PCI and those AF patients have a higher age-adjusted all cause inpatient mortality. There is a decline in total number of PCIs over time in US. Atrial fibrillation, chronic kidney disease, peripheral artery disease, MI and cardiogenic shock were associated with increased mortality following PCI