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Spectinamides 1599 and 1810 are lead spectinamide compounds currently under preclinical development to treat multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis. These compounds have previously been tested at various combinations of dose level, dosing frequency, and route of administration in mouse models of Mycobacterium tuberculosis (Mtb) infection and in healthy animals. Physiologically based pharmacokinetic (PBPK) modeling allows the prediction of the pharmacokinetics of candidate drugs in organs/tissues of interest and extrapolation of their disposition across different species. Here, we have built, qualified, and refined a minimalistic PBPK model that can describe and predict the pharmacokinetics of spectinamides in various tissues, especially those relevant to Mtb infection. The model was expanded and qualified for multiple dose levels, dosing regimens, routes of administration, and various species. The model predictions in mice (healthy and infected) and rats were in reasonable agreement with experimental data, and all predicted AUCs in plasma and tissues met the two-fold acceptance criteria relative to observations. To further explore the distribution of spectinamide 1599 within granuloma substructures as encountered in tuberculosis, we utilized the Simcyp granuloma model combined with model predictions in our PBPK model. Simulation results suggest substantial exposure in all lesion substructures, with particularly high exposure in the rim area and macrophages. The developed model may be leveraged as an effective tool in identifying optimal dose levels and dosing regimens of spectinamides for further preclinical and clinical development.

Recent mouse knockout studies identified adapter protein-2-associated kinase 1 (AAK1) as a viable target for treating neuropathic pain. BMS-986176/LX-9211 (

Globally, water and energy demands are increasing continuously, while the storage capacity of structures like dams and reservoirs is reducing due to sediment-induced problems. Study of the reservoir sedimentation is essential for restoring the storage capacities to ensure the increasing water and energy demands. This study suggested the methodology for preparing the revised elevation–area–capacity curve for a reservoir for its efficient use. Also, it focused on two important issues through an example—estimation of the loss of the live storage capacity of the reservoir due to sedimentation and remedial measures to regain the lost capacity. In the present study, reservoir sedimentation is estimated using satellite remote sensing technique (SRS) considering a case of the Ujjani reservoir located in Maharashtra State, India. The modified normalized difference water index (MNDWI) is employed to determine the water surface area using ERDAS Imagine software. The loss in live capacity because of deposition of sedimentation over 41 years is determined and estimated to be 174.592 Mm3 showing the rate of capacity loss as 4.26 Mm3/year, which is 11.23% loss of the original capacity under study zone. To regain the storage capacity of the reservoir, it is proposed to adopt manual and or mechanical dredging with flushing for desilting the deposited sediment in the reservoir.

Recent mouse knockout studies identified adapter protein-2 associated kinase 1 (AAK1) as a viable target for treating neuropathic pain. Potent small-molecule inhibitors of AAK1 have been identified and show efficacy in various rodent pain models. (

Soil erosion, if remain non attentive, will increase the sediment load of the river and also affecting the life of the hydraulic structures constructed across it. Hence, proper investigations related to the soil erosion is very much essential for watershed planners and designers. In the present study, morphometric analysis is carried out for basic, linear, areal, shape and landscape aspects using 28 morphometric parameters for Bhima river watershed to prioritize and categorized it based on its erosive potential. Total 48 toposheet of Survey of India of the scale 1:50,000 are used to delineate the watersheds for the preparation of base map containing information about drainage, contours, etc. so as to ensure accuracy and quality of the work. The All India Soil and Land Use Survey (AISLUS) codification is adopted for the study area. According to AISLUS, the study area falls under region 4, covered in 19 watersheds. Morphometric parameters in Arc-GIS software and compound factor method is employed to identify the sub-watersheds which are susceptible to soil erosion. Final Priority Ranking (FPR) based category map of watersheds is reported in this study by categorized it under five categories indicating % area of each category (very high category: 15.94%; high category: 23.50%; medium category: 12.73%; low category: 23.90%; and very low category: 23.93%). Based on the findings, this study is suggesting suitable sites soil conservation practices for reducing the sediment load in Bhima river watersheds as well as Ujjani reservoir, which will be useful to the concerning authorities for better management.

Despite decades of research, tuberculosis remains a leading cause of death from a single infectious agent. Spectinamides are a promising novel class of antituberculosis agents, and the lead spectinamide 1810 has demonstrated excellent efficacy, safety, and drug-like properties in numerous in vitro and in vivo assessments in mouse models of tuberculosis. In the current dose ranging and dose fractionation study, we used 29 different combinations of dose level and dosing frequency to characterize the exposure-response relationship for spectinamide 1810 in a mouse model of Mycobacterium tuberculosis infection and in healthy animals. The obtained data on 1810 plasma concentrations and counts of CFU in lungs were analyzed using a population pharmacokinetic/pharmacodynamic (PK/PD) approach as well as classical anti-infective PK/PD indices. The analysis results indicate that there was no difference in the PK of 1810 in infected compared to healthy, uninfected animals. The PK/PD index analysis showed that bacterial killing of 1810 in mice was best predicted by the ratio of maximum free drug concentration to MIC (fC(max)/MIC) and the ratio of the area under the free concentration-time curve to the MIC (fAUC/MIC) rather than the cumulative percentage of time that the free drug concentration is above the MIC (f%T(MIC)). A novel PK/PD model with consideration of postantibiotic effect could adequately describe the exposure-response relationship for 1810 and supports the notion that the in vitro observed postantibiotic effect of this spectinamide also translates to the in vivo situation in mice. The obtained results and pharmacometric model for the exposure-response relationship of 1810 provide a rational basis for dose selection in future efficacy studies of this compound against M. tuberculosis.

Cellular senescence is one of the prevailing issues in cancer therapeutics that promotes cancer relapse, chemoresistance, and recurrence. Patients undergoing persistent chemotherapy often develop drug-induced senescence. Docetaxel, an FDA-approved treatment for prostate cancer, is known to induce cellular senescence which often limits the overall survival of patients. Strategic therapies that counter the cellular and drug-induced senescence are an unmet clinical need. Towards this an effort was made to develop a novel therapeutic strategy that targets and removes senescent cells from the tumors, we developed a nanoformulation of tannic acid−docetaxel self-assemblies (DSAs). The construction of DSAs was confirmed through particle size measurements, spectroscopy, thermal, and biocompatibility studies. This formulation exhibited enhanced in vitro therapeutic activity in various biological functional assays with respect to native docetaxel treatments. Microarray and immunoblot analysis results demonstrated that DSAs exposure selectively deregulated senescence associated TGFβR1/FOXO1/p21 signaling. Decrease in β-galactosidase staining further suggested reversion of drug-induced senescence after DSAs exposure. Additionally, DSAs induced profound cell death by activation of apoptotic signaling through bypassing senescence. Furthermore, in vivo and ex vivo imaging analysis demonstrated the tumor targeting behavior of DSAs in mice bearing PC-3 xenograft tumors. The antisenescence and anticancer activity of DSAs was further shown in vivo by inhibiting TGFβR1 proteins and regressing tumor growth through apoptotic induction in the PC-3 xenograft mouse model. Overall, DSAs exhibited such advanced features due to a natural compound in the formulation as a matrix/binder for docetaxel. Overall, DSAs showed superior tumor targeting and improved cellular internalization, promoting docetaxel efficacy. These findings may have great implications in prostate cancer therapy.

Paclitaxel (PTX) is a gold standard chemotherapeutic agent for breast, ovarian, pancreatic and non-small cell lung carcinoma. However, in clinical use PTX can have adverse side effects or inadequate pharmacodynamic parameters, limiting its use. Nanotechnology is often employed to reduce the therapeutic dosage required for effective therapy, while also minimizing the systemic side effects of chemotherapy drugs. However, there is no nano formulation of paclitaxel with chemosensitization motifs built in. With this objective, we screened eleven pharmaceutical excipients to develop an alternative paclitaxel nanoformulation using a self-assembly method. Based on the screening results, we observed tannic acid possesses unique properties to produce a paclitaxel nanoformulation, i.e., tannic acid-paclitaxel (TAP). This stable TAP nanoformulation, referred to as TAP nanoparticles (TAP NPs), showed a spherical shape of 102.22±14.05 nm and negative zeta potential of −8.85±0.44 mV. The presence of PTX in TAP NPs was confirmed by Fourier Transform Infrared (FTIR) spectra, thermogravimetric analyzer (TGA) scans, and X-ray diffraction (XRD). Encapsulation efficiency of PTX in TAP NPs was determined to be > 96.49±0.43 %. Intracellular drug uptake of plain drug PTX on breast cancer cells (MDA-MB-231) shows more or less constant drug concentration from 2–6 hours, suggesting drug efflux by the P-gp transporters, over TAP NPs, in which PTX uptake was more than 95.52+11.01% in 6 hours, as analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Various biological assays such as proliferation, clonogenic formation, invasion, and migration confirm superior anticancer effects of TAP NPs over plain PTX at all tested concentrations. P-gp expression Rhodamine-123 (RH123), beta-tubulin stabilization, Western blot, and microarray analysis further confirm the improved therapeutic potential of TAP NPs. These results suggest that the TAP nanoformulation provides an important reference for developing a therapeutic nanoformulation affording pronounced, enhanced effects in breast cancer therapy.

Despite decades of research, tuberculosis remains the oldest pathogen-based disease that is the leading cause of death from a single infectious agent. Among many anti-tubercular therapies under investigation, the semisynthetic compounds spectinamides are a promising novel class of anti-tuberculosis agents. One such lead candidate, spectinamide 1810, and backup spectinamide 1599 have demonstrated excellent efficacy, safety, and drug-like properties in various in vitro and in vivo assessments. The dose-ranging and dose fractionation studies were designed to characterize the dose-exposure-response relationship for lead and backup spectinamide in a mouse model of Mycobacterium tuberculosis infection. In this current study, we used 26 and 23 combinations of dose level and dosing frequency for the lead and backup spectinamide, respectively. The dedicated pharmacokinetic studies with a collection of series of blood samples were conducted in healthy animals. Population pharmacokinetic analysis was performed using non-linear mixed effect modeling to estimate pharmacokinetic parameters in healthy animals. The Bayesian principles were applied for reliable pharmacokinetic estimation in infected animals by using informed priors obtained from healthy animals. The individual pharmacokinetic parameters were obtained for infected animals through post-hoc estimation and subsequently used for pharmacokinetic/-pharmacodynamic (PK/PD) indices and mechanism-based PK/PD modeling. The obtained data on spectinamides’ plasma concentrations and counts of colony-forming units were analyzed using a PK/PD approach as well as classical anti-infective PK/PD indices. The population pharmacokinetic analysis results suggest that there is no difference in the pharmacokinetic parameters of lead and backup spectinamide in infected animals as compared to healthy animals. The PK/PD index analysis showed that the efficacy of spectinamide 1810 is largely driven by concentration (Cmax/MIC) and exposure (AUC/MIC) rather than a threshold minimum inhibitory level (T>MIC). Although similar results were obtained for spectinamide 1599 in previously performed in vitro experiments, in the present in vivo studies, spectinamide 1599 did not demonstrate the expected correlation between efficacy and PK/PD indices. Therefore, we could not identify major drivers for the efficacy of this compound. Additionally, a novel mechanism-based PK/PD model with consideration to post-antibiotic effect could adequately describe the exposure-response relationship for lead and backup spectinamide. This supports the idea that the in vitro observed post-antibiotic effect of these spectinamides can translate to the in vivo situation, as well. Altogether we suggest, the obtained results and pharmacometric model for the exposure-response relationship of lead and backup spectinamides provide a rational basis for dose selection for future efficacy studies of these compounds against Mycobacterium tuberculosis in mice and other animal species.

Background: Clindamycin’s bitter taste and odor is known to affect treatment adherence in children. Recently, a formulation of clindamycin HCl complexed with ion exchange resin IRP 69 was shown to ...

Spectinamides are a novel series of spectinomycin analogs being developed for the treatment of tuberculosis. Intrapulmonary aerosol (IPA) administration of lead spectinamide 1599 has previously been shown to be more efficacious than subcutaneous (SC) administration at comparable doses. The objective of the current study was to characterize the disposition of 1599 in plasma and lungs in mice in order to provide a potential rationale for the observed efficacy differences. 200 mg/kg of 1599 was administered to healthy BALB/c mice by SC injection or by IPA delivery. Plasma and major organs were collected at specified time points until 8 h after dosing. Drug concentrations were measured by LC-MS/MS and analyzed by noncompartmental pharmacokinetic analysis. 1599 demonstrated rapid absorption into plasma after IPA and SC administration, resulting in very similar plasma exposure for both routes. In contrast, drug exposure in the lungs was 48 times higher following IPA as compared to SC administration, which is highly desirable as the lungs are the main site of infection in pulmonary TB. The higher local exposure in the lungs is likely the basis for the increased efficacy after IPA compared to SC administration. Overall, this study supports the pulmonary route as a potential pathway for the treatment of tuberculosis with 1599.

Certain aromatic nitriles are well-known inhibitors of cysteine proteases. The mode of action of these compounds involves the formation of a reversible or irreversible covalent bond between the nitrile and a thiol group in the active site of the enzyme. However, the reactivity of these aromatic nitrile-substituted heterocycles may lead inadvertently to nonspecific interactions with DNA, protein, glutathione, and other endogenous components, resulting in toxicity and complicating the use of these compounds as therapeutic agents. In the present study, the intrinsic reactivity and associated structure-property relationships of cathepsin K inhibitors featuring substituted pyridazines [6-phenylpyridazine-3-carbonitrile, 6-(4-fluorophenyl)pyridazine-3-carbonitrile, 6-(4-methoxyphenyl)pyridazine-3-carbonitrile, 6-p-tolylpyridazine-3-carbonitrile], pyrimidines [5-p-tolylpyrimidine-2-carbonitrile, 5-(4-fluorophenyl)pyrimidine-2-carbonitrile], and pyridines [5-p-tolylpicolinonitrile and 5-(4-fluorophenyl)picolinonitrile] were evaluated using a combination of computational and analytical approaches to establish correlations between electrophilicity and levels of metabolites that were formed in glutathione- and N-acetylcysteine-supplemented human liver microsomes. Metabolites that were characterized in this study featured substituted thiazolines that were formed following rearrangements of transient glutathione and N-acetylcysteine conjugates. Peptidases including γ-glutamyltranspeptidase were shown to catalyze the formation of these products, which were formed to lesser extents in the presence of the selective γ-glutamyltranspeptidase inhibitor acivicin and the nonspecific peptidase inhibitors phenylmethylsulfonyl fluoride and aprotinin. Of the chemical series mentioned above, the pyrimidine series was the most susceptible to metabolism to thiazoline-containing products, followed, in order, by the pyridazine and pyridine series. This trend was in keeping with the diminishing electrophilicity across these series, as demonstrated by in silico modeling. Hence, mechanistic insights gained from this study could be used to assist a medicinal chemistry campaign to design cysteine protease inhibitors that were less prone to the formation of covalent adducts.

A flexure based compliant parallel (4-bar) mechanism for linear translational motion actuated via a precision slide has been proposed. Due to the flexures a miniaturised mechanism is possible overcoming the limitations of rigid link mechanisms. In addition since a compliant mechanism has a monolithic structure no assembly is required. The compliant mechanism is designed using Pseudo Rigid Body Model (PRBM) approach and results obtained are compared with finite element analysis. An experimental setup is developed incorporating a microslide as an actuator for 4-bar compliant mechanism and displacement is measured using 3D optical profilometer. The performance of the compliant parallel mechanism demonstrated by experiments validates the simulation results and hence PRBM results. The effect of point of motion actuation on performance of mechanism is also investigated.

Structural elucidation is an integral part of drug discovery and development. In recent years, due to acceleration of the drug discovery and development process, there is a significant need for highly efficient methodologies for structural elucidation. In this work, we devised and standardized a simple and economical online hydrogen-deuterium exchange methodology, which can be used for structure elucidation purposes. Deuterium oxide (D2O) was infused as a postcolumn addition using the syringe pump at the time of elution of the analyte. The obtained hydrogen/deuterium (H/D) exchange spectrum of the unknown analyte was compared with the nonexchanged spectrum, and the extent of deuterium incorporation was delineated by using an algorithm to deconvolute partial H/D exchange, which confirmed the number of labile hydrogen(s) in the analyte. The procedure was standardized by optimizing flow rates of LC output, D2O infusion, sheath gas, and auxiliary gas using the model compound sulfasalazine. The robustness of the methodology was demonstrated by performing sensitivity analysis of various parameters such as concentrations of analyte, effect of matrices, concentrations of aqueous mobile phase, and types of LC modifiers. The optimized technique was also applied to chemically diverse analytes and tested on various mass spectrometers. Moreover, utility of the technique was demonstrated in the areas of impurity profiling and metabolite identification, taking pravastatin-lactone and N-oxide desloratidine, as examples.