Inhibition Of Isoenzymes Research Articles

Deep Learning Models Compared to Experimental Variability for the Prediction of CYP3A4 Time-Dependent Inhibition.

Most drugs are mainly metabolized by cytochrome P450 (CYP450), which can lead to drug-drug interactions (DDI). Specifically, time-dependent inhibition (TDI) of CYP3A4 isoenzyme has been associated with clinically relevant DDI. To overcome potential DDI issues, high-throughput in vitro assays were established to assess the TDI of CYP3A4 during the discovery and lead optimization phases. However, in silico machine learning models would enable an earlier and larger-scale assessment of TDI potential liabilities. For CYP inhibition, most modeling efforts have focused on highly imbalanced and small data sets. Moreover, assay variability is rarely considered, which is key to understand the model's quality and suitability for decision-making. In this work, machine learning models were built for the prediction of TDI of CYP3A4, evaluated prospectively, and compared to the variability of the experimental assay. Different modeling strategies were investigated to assess their influence on the model's performance. Through multitask learning, additional data sets were leveraged for model building, coming from public databases, in-house CYP-related assays, or other pharmaceutical companies (federated learning). Apart from the numerical prediction of inactivation rates of CYP3A4 TDI, three-class predictions were carried out, giving a negative (inactivation rate kobs < 0.01 min-1), weak positive (0.01 ≤ kobs ≤ 0.025 min-1), or positive (kobs > 0.025 min-1) output. The final multitask graph neural network model achieved misclassification rates of 8 and 7% for positive and negative TDI, respectively. Importantly, the presented deep learning-based predictions had a similar precision to the reproducibility of in vitro experiments and thus offered great opportunities for drug design, early derisk of DDI potential, and selection of experiments. To facilitate CYP inhibition modeling efforts in the public domain, the developed model was used to annotate ∼16 000 publicly available structures, and a surrogate data set is shared as Supporting Information.

In silico Exploration of Pharmacological and Molecular Descriptor Properties of Salacinol and Its Related Analogues

Salacinol and its related analogues have been known for their potent α-glucosidase inhibitor activity and making them interesting candidates for a new type of anti-diabetic agent. Therefore, it is essential to investigate the physicochemical properties, pharmacological parameters, and toxicity profile of these anti-diabetic agents. In this study, a comprehensive in-silico approach was used to explore the absorption, distribution, metabolism, excretion, and toxicity profiles of salacinol and its related analogues. In addition, to gain a better knowledge of structural and electrical characteristics, global and local reactivity descriptors, and molecular electrostatic potential were calculated and discussed by using DFT at the B3LYP/6–311++G (d, p) level of theory. The results explored that all the studied compounds have low GI absorption and are substrates for P-glycoprotein. None of the compounds can cross the BBB, and none of the compounds are inhibitors of cytochrome P450 isoenzymes. We also found that all compounds have various potential to interact with a wide range of biological targets, including GPCRs, enzymes, ion channels, kinases, and nuclear receptors. Additionally, all compounds have low toxicity and are unlikely to cause any major health hazards in terms of hepatotoxicity, mutagenicity, cardiotoxicity, cytotoxicity, and immunotoxicity. The molecular electrostatic potential map shows that the negative potential sites are in electronegative oxygen atoms, while the positive potential sites are around the hydrogen atoms. The present study concludes that salacinol and its analogues might be a promising safe and effective candidate for the development of therapeutic drugs derived from natural sources. However, some of their properties should be considered in the context of drug development and tissue protection strategies.

Selective targeting of human TET1 by cyclic peptide inhibitors: Insights from biochemical profiling

Ten-Eleven Translocation (TET) enzymes are Fe(II)/2OG-dependent oxygenases that play important roles in epigenetic regulation, but selective inhibition of the TETs is an unmet challenge. We describe the profiling of previously identified TET1-binding macrocyclic peptides. TiP1 is established as a potent TET1 inhibitor (IC50 = 0.26 µM) with excellent selectivity over other TETs and 2OG oxygenases. TiP1 alanine scanning reveals the critical roles of Trp10 and Glu11 residues for inhibition of TET isoenzymes. The results highlight the utility of the RaPID method to identify potent enzyme inhibitors with selectivity over closely related paralogues. The structure–activity relationship data generated herein may find utility in the development of chemical probes for the TETs.

Design and synthesis of novel dithiazole carboxylic acid Derivatives: In vivo and in silico investigation of their Anti-Inflammatory and analgesic effects

Inflammation is a complex set of interactions that can occur in tissues as the body's defensive response to infections, trauma, allergens, or toxic compounds. Therefore, in almost all diseases, it can be observed because of primary or secondary reasons.Since it is important to control and even eliminate the symptoms of inflammation in the treatment of many diseases, anti-inflammatory and analgesic drugs are always needed in the clinic. Therefore, the discovery of new anti-inflammatory/analgesic drugs with increased effectiveness and safer side effect profiles is among the popular topics of medicinal chemistry. Therefore, in this study, in order to synthesize and diversify new molecules, we focused on the N,N-dithiazole carboxylic acid core and linked it with the chalcone functional group.The final eleven molecules were analyzed via HRMS, 1H NMR, and 13C NMR. The antinociceptive effects of the test compounds were examined by tail-clip, hot-plate, and formalin methods in mice, while their anti-inflammatory activities were investigated by carrageenan-induced inflammation tests in rats. The motor activities of the experimental animals were evaluated using an activity-meter device. Obtained findings revealed that none of the test compounds (10 mg/kg) were effective in the tail-clip and hot-plate tests. However, compounds 4b, 4c, 4f, 4 h, and 4 k in the serial shortened the paw-licking times of mice in the late phase of the formalin test indicating that these compounds had peripherally-mediated antinociceptive effects. The same compounds, moreover, showed potent anti-inflammatory effects by significantly reducing paw edema of rats in the inflammation tests. To provide an approach to pharmacological findings regarding possible mechanisms of action, the binding modes of the most active compounds were investigated by in silico approaches. The results of molecular docking studies indicated that the anti-inflammatory and analgesic activities of the compounds might be related to the inhibition of both COX-1 and COX-2 isoenzymes. Findings obtained from in silico studies showed that 4 k, which was chosen as a model for its analogs in the series, forms strong bindings to the basic residues (Arg120, Tyr355), side pocket loop area and deep hydrophobic regions of the enzyme. Moreover, results of the molecular dynamics simulation studies revealed that ligand-COX enzyme complexes are quite stable. Obtained results of in vivo and in silico studies are in harmony, and all together point out that compounds 4b, 4c, 4f, 4 h, and 4 k have significant anti-inflammatory and analgesic activities with good ADME profiles.The potential of the derivatives, whose pharmacological activities were revealed for the first time in this study, as anti-inflammatory and analgesic drug candidates, needs to be evaluated through comprehensive clinical studies.

Exploring Astrodaucus orientalis (L.) Drude: Phytochemical Analysis and its Biological Potential Against Alzheimer's and Diabetes.

In current study antioxidant, antidiabetic, antimicrobial, anticholinesterase, and human carbonic anhydrase I, and II (hCA I and II) isoenzymes inhibition activities of Astrodaucus orientalis different parts were investigated. Achetylcholinesterse (AChE) and butyrylcholinesterse (BChE) inhibitory activities of octyl acetate were determined via molecular docking. Quantitative assessment of specific secondary metabolites was conducted using LC-MS/MS. An examination of chemical composition of essential oils was carried out by GC-MS/MS. A thorough exploration of plant's anatomical characteristics was undertaken. The highest phenolics level and DPPH antioxidant capacity were seen in root and fruit. Fruit essential oil demonstrated the highest AChE inhibition (44.13±3.61 %), while root dichloromethane sub-extract had the best inhibition towards BChE (86.13±2.58 %). Cytosolic hCA I, and II isoenzymes were influentially inhibited by root oil with 1.974 and 2.207 μM IC50 values, respectively. The most effective extracts were found to be root all extract/sub-extracts (except water) against C. tropicalis and C. krusei strains with MIC value 160>μg/mL. Sabinene (29.4 %), α-pinene (20.2 %); octyl acetate (54.3 %); myrcene (28.0 %); octyl octanoate (71.3 %) were found principal components of aerial parts, roots, flowers, and fruits, respectively. Flower essential oil, fruit dicloromethane and ethyl acetate exhibited potent α-glucosidase inhibitory activity with 900, 40, and 937 μg/mL IC50 values, respectively.

A study of the interaction space of two lactate dehydrogenase isoforms (LDHA and LDHB) and some of their inhibitors using proteochemometrics modeling

Lactate dehydrogenase (LDH) is a tetramer enzyme that converts pyruvate to lactate reversibly. This enzyme becomes important because it is associated with diseases such as cancers, heart disease, liver problems, and most importantly, corona disease. As a system-based method, proteochemometrics does not require knowledge of the protein's three-dimensional structure, but rather depends on the amino acid sequence and protein descriptors. Here, we applied this methodology to model a set of LDHA and LDHB isoenzyme inhibitors. To implement the proteochemetrics method, the camb package in the R Studio Server programming environment was used. The activity of 312 compounds of LDHA and LDHB isoenzyme inhibitors from the valid Binding DB database was retrieved. The proteochemometrics method was applied to three machine learning algorithms gradient amplification model, random forest, and support vector machine as regression methods to find the best model. Through the combination of different models into an ensemble (greedy and stacking optimization), we explored the possibility of improving the performance of models. For the RF best ensemble model of inhibitors of LDHA and LDHB isoenzymes, and were 0.66 and 0.62, respectively. LDH inhibitory activation is influenced by Morgan fingerprints and topological structure descriptors.

Synthesis, characterization and docking studies of benzenesulfonamide derivatives containing 1,2,3-triazole as potential ınhibitor of carbonic anhydrase I-II enzymes

Carbonic Anhydrases (CAs) are an important family of metalloenzymes that contain zinc (Zn2+) ions in their active site and catalyze the conversion of carbon dioxide to bicarbonate and proton and found in all living organisms. Sulfonamides are well-known inhibitors of CAs isoenzymes. In this study, a series of benzenesulfonamide derivatives (9a–h) containing 1,2,3-triazole-moiety were designed, synthesized and their structures were characterized by spectroscopic methods. In addition, molecular structures of compounds 5a, 5 b, 9e and 9f were elucidated by X-ray diffraction technique. To investigate drug similarity of 9a–h compounds, Lipinski’s five rules (ADMET: absorption, distribution, metabolism, excretion and toxicity) were carried out by in silico studies. According to results, the compounds showed drug-like properties. Docking studies were applied to determine the scores, interactions and binding modes of compounds 9a–h against hCA I and hCA II enzymes. Compound 9c (-5.13 kcal/mol docking score) against hCA I enzyme and 9 h (-5.32 kcal/mol docking score) against hCA II enzyme showed potent inhibitory properties. The binding interactions of the compounds with the carbonic anhydrases were examined by docking studies. Communicated by Ramaswamy H. Sarma

The synthesis, biological evaluation and in silico studies of asymmetric 3,5-diaryl-rhodanines as novel inhibitors of human carbonic anhydrase isoenzymes

The synthesis of rhodanine core, which forms the main skeleton of organics used as a large number of drugs, is obtained with more green approaches is very significant. Additionally, asymmetrical functionalization from C5 and N(3) positions of 3-NH2-Rh (1) via a green approach is representing a challenge. In this connect, the primary goal of this study is to obtain novel asymmetric 3,5-diarylRhs by an effective green synthetic approach. For this, initially, the reactions of the variety of aromatic aldehydes with 5-Ar-Rhs 2a and 2b were investigated by changing parameters such as catalyst, solvent, and temperature. As a result of the studies, novel asymmetric 3,5-diarylRhs were obtained as the main product of acetic acid catalyst reactions carried out at reflux temperatures of ethanol. Moreover, the site-selective reduction of the imine group in the structure of the asymmetric 3,5-diarylRhs was also carried out within the scope of this study. Following synthesis, we also carried out inhibition studies of novel 3,5-diarylRhs against cytosolic human carbonic anhydrase I, and II (hCA I and II) isoforms. As a result of these inhibition studies, inhibition constants (Ki) for hCA I and hCA II were found in the range of 107.26 ± 31.18 to 601.97 ± 46.44 nM, and 127.72 ± 15.75 to 480.13 ± 47.24 nM, respectively. In order to support the results obtained as a result of the inhibition studies, molecular docking studies of the asymmetrical 3,5-diarylRhs 4i and 4l showing the best activity for hCA I and hCA II were also carried out, and the morphology of the binding was examined. Furthermore, the organics comply with Lipinski's and Jorgensen's rules of all compounds were determined by calculated ADME and drug-likeness parameters. That is, the ADME and drug-likeness parameters of the new 3,5-diarylRhs showed that they are not only with hCA I and hCA II inhibitory activities but also with appropriate drug-likeness properties and physicochemical parameters.

Examination of the pharmacokinetics and differential inhibition of cyclooxygenase isoenzymes in New Zealand white rabbits (Oryctolagus cuniculus) by the Non-Steroidal anti-inflammatory Robenacoxib.

Effective rabbit analgesia is challenging, and there are few studies available on the newer COX-2 selective NSAIDs, such as robenacoxib. This study aimed to establish the pharmacokinetics of oral and subcutaneous robenacoxib, describe its inhibitory actions on COX enzymes, and develop dosing, using six healthy New Zealand white rabbits. Pharmacokinetics were determined from plasma concentrations after oral administration of robenacoxib (0.83-0.96 mg/kg) and also after subcutaneous administration (2mg/kg). The inhibitory actions of robenacoxib were evaluated by measuring plasma concentrations of thromboxane B2 (TBX2 ) and prostaglandin E2 (PGE2 ) as surrogate markers of cyclooxygenase enzyme isoform inhibition. The mean maximum concentration for oral and subcutaneous administration was 0.23 μg/ml and 5.82 μg/ml, respectively. Oral robenacoxib administration did not demonstrate a significant difference between any time point for PGE2 or TBX2 , though subcutaneous administration did for both. There was no significant difference in PGE2 or TBX2 concentrations at any time point when comparing subcutaneous versus oral routes. Although the results support that plasma robenacoxib exceeds the therapeutic levels compared to dogs and cats, there was little significance in the difference in the changes associated with COX-1 and COX-2 inhibition. Further studies are warranted to determine appropriate dosing, safety, and efficacy in rabbits.

Biological activity and molecular docking studies of some N-phenylsulfonamides against cholinesterases and carbonic anhydrase isoenzymes.

In this research, a series of N-phenylsulfonamide derivatives (1-12) were designed, synthesized, and investigated for their inhibitory potencies against carbonic anhydrase isoenzymes I, II, and IX (hCA I, hCA II, and hCA IX) and cholinesterases (ChE), namely, acetylcholinesterase and butyrylcholinesterase. These compounds, whose inhibition potentials were evaluated for the first time, were characterized by spectroscopic techniques (1 H- and 13 C-NMR and FT-IR). CA isoenzyme inhibitors are significant therapeutic targets, especially owing to their preventive/activation potential in the therapy processes of some diseases such as cancer, osteoporosis, and glaucoma. On the other hand, Cholinesterase inhibitors are valuable molecules with biological importance that can be employed in the therapy process of Alzheimer's patients. The results showed that the tested molecules had enzyme inhibition activities ranging from 9.7 to 93.7nM against these five metabolic enzymes. Among the tested molecules, the methoxy and the hydroxyl group-containing compounds 10, 11, and 12 exhibited more enzyme inhibition activities when compared to standard compounds acetazolamide, sulfapyridine, and sulfadiazine for CA isoenzymes and neostigmine for ChE, respectively. Of these three molecules, compound 12, which had a hydroxyl group in the para position in the aromatic ring, was determined to be the most active molecule against all enzymes. In silico work, molecular docking has also shown similar results and is consistent with the experimental data in the study. As a result, we can say that some of the tested molecules might be used as promising inhibitor candidates for further studies on this topic.

Contribution of HIF-P4H isoenzyme inhibition to metabolism indicates major beneficial effects being conveyed by HIF-P4H-2 antagonism

Hypoxia-inducible factor (HIF) prolyl 4-hydroxylases (HIF-P4Hs 1–3) are druggable targets in renal anemia, where pan-HIF-P4H inhibitors induce an erythropoietic response. Preclinical data suggest that HIF-P4Hs could also be therapeutic targets for treating metabolic dysfunction, although the contributions of HIF-P4H isoenzymes in various tissues to the metabolic phenotype are inadequately understood. Here, we used mouse lines that were gene-deficient for HIF-P4Hs 1 to 3 and two preclinical pan-HIF-P4H inhibitors to study the contributions of these isoenzymes to the anthropometric and metabolic outcome and HIF response. We show both inhibitors induced a HIF response in wildtype white adipose tissue (WAT), liver, and skeletal muscle and alleviated metabolic dysfunction during a 6-week treatment period, but they did not alter healthy metabolism. Our data indicate that HIF-P4H-1 contributed especially to skeletal muscle and WAT metabolism and that its loss lowered body weight and serum cholesterol levels upon aging. In addition, we found HIF-P4H-3 had effects on the liver and WAT and its loss increased body weight, adiposity, liver weight and triglyceride levels, WAT inflammation, and cholesterol levels and resulted in hyperglycemia and insulin resistance, especially during aging. Finally, we demonstrate HIF-P4H-2 affected all tissues studied; its inhibition lowered body and liver weight and serum cholesterol levels and improved glucose tolerance. We found very few HIF target metabolic mRNAs were regulated by the inhibition of three isoenzymes, thus suggesting a potential for selective therapeutic tractability. Altogether, these data provide specifications for the future development of HIF-P4H inhibitors for the treatment of metabolic diseases.

Problems of the thin endometrium. New possibilities of FDE-5 inhibitors

The article is devoted to a review of the literature about the thin endometrium and its correction today. The problem of thin endometrium is very significant in cases of unsuccessful embryo implantation. There is no generally accepted approach to the definition of “thin endometrium” and ways of its correction in the literature. Phosphodiesterase type 5 (PDE5) inhibitors are considered to play a role in increasing endometrial thickness and improving pregnancy outcomes. Their action consists of various mechanisms, in particular, such as the induction of vasodilating effect through the effect on signaling to vascular smooth muscle, through the regulation of cell proliferation and induction of angiogenesis by increasing the expression of tumor suppressor factor (p53) and vascular endothelial growth factor A, the inhibition of inflammation by reducing the regulation of proinflammatory cytokines. Although PDE5 inhibitors increase the endometrial thickness through the various mechanisms, especially in women with thin endometrium, it does not necessarily mean that they have a positive effect in all clinical situations. Meanwhile, the successful outcome may be affected by the time of use of the drug, the type of infertility treatment, the main diseases such as pelvic disorders and inflammation. Therefore, there are ambiguous issues that need further research in this problem. Oral PDE5 inhibitors are also used as first-line therapy for the treatment of erectile dysfunction (ED), they have proven effectiveness, tolerability, action and couple satisfaction. Avanafil is the only selective inhibitor of the PDE5 isoenzyme with a low frequency of side effects compared to other drugs in this group. The high tolerability of these drugs has made them an attractive tool for the study of further physiological functions outside the ED with benefits for many non-sexual consequences.

Design, development, and evaluation of polymer-coated delayed-release dosage form of Duloxetine hydrochloride

Medication are vital for life many medications, as tablets, suspensions, and capsules, are taken by the oral route, which has a systematic effect as it reaches different body sections via the bloodstream. Suspension is the best formulation for the treatment of various diseases such as depression for better patient compliance. Many types of drugs are there on the market for the treatment of depression-like fluoxetine, atypical antipsychotic, norepinephrine, monoamine oxidase inhibitors, a potent inhibitor of cytochrome P-450 isoenzymes, and serotonin reuptake inhibitors are also used. There are some drawbacks such as dry mouth, constipation, sedation, insomnia, tachycardia, sweating, less patient compliance, etc. Duloxetine HCl is a BCS class 2 drug that is selective serotonin and norepinephrine inhibitor. It helps to stop the pain signals in the brain by maintaining the normal levels of serotonin and norepinephrine in the brain. To overcome the drawback of patient compliance, the present study is to develop and optimize polymer-coated delayed-release suspension of Duloxetine HCl and opens a new window for researchers to develop a suspension for the treatment of depression.

Alisertib shows negligible potential for perpetrating pharmacokinetic drug-drug interactions on ABCB1, ABCG2 and cytochromes P450, but acts as dual-activity resistance modulator through the inhibition of ABCC1 transporter

Alisertib (MLN8237), a novel Aurora A kinase inhibitor, is currently being clinically tested in late-phase trials for the therapy of various malignancies. In the present work, we describe alisertib's potential to perpetrate pharmacokinetic drug-drug interactions (DDIs) and/or to act as an antagonist of multidrug resistance (MDR). In accumulation assays, alisertib potently inhibited ABCC1 transporter, but not ABCB1 or ABCG2. The results of molecular modeling suggested a bifunctional mechanism for interaction on ABCC1. In addition, alisertib was characterized as a low- to moderate-affinity inhibitor of recombinant CYP3A4, CYP2C8, CYP2C9, CYP2C19, and CYP2D6 isoenzymes, but without potential clinical relevance. Drug combination studies revealed the capability of alisertib to synergistically antagonize ABCC1-mediated resistance to daunorubicin. Although alisertib exhibited substrate characteristics toward ABCB1 transporter in monolayer transport assays, comparative proliferation studies showed lack of its MDR-victim behavior in cells overexpressing ABCB1 as well as ABCG2 and ABCC1. Lastly, alisertib did not affect the expression of ABCC1, ABCG2, ABCB1 transporters and CYP1A2, CYP3A4, CYP2B6 isozymes on mRNA level in various systemic and tumoral models. In conclusion, our study suggests that alisertib is a drug candidate with negligible potential for perpetrating systemic pharmacokinetic DDIs on ABCB1, ABCG2 and cytochromes P450. In addition, we introduce alisertib as an effective dual-activity chemosensitizer whose MDR-antagonistic capacities are not impaired by efflux or effect on MDR phenotype. Our in vitro findings provide important pieces of information for clinicians when introducing alisertib into the clinical area.

Formulation Development and Characterization of Darunavir and Ritonavir Sustained Release Tablets Using Quality by Design Approach

Darunavir is a nonpeptidic inhibitor of protease and is primarily metabolized by cytochrome P450 3A (CYP3A) isoenzymes. It is usually coadministered with low-dose ritonavir (Darunavir/r). Ritonavir is an inhibitor of CYP3A isoenzymes and pharmacologically enhances Darunavir which leads to increased plasma concentrations of darunavir and allows for daily lower dose. Here, we have developed combination SR formulation of Darunavir and Ritonavir and evaluated. In vitro drug release of all formulations was carried out in dissolution medium 900ml of pH 3.0, 0.05 M Sodium Phosphate Buffer + 2% Tween 20 for 75 RPM USP II apparatus (paddle). The results shown that, all the formulations of matrix tablets shown the good release of drug from trialed formulations however all formulations were not releasing the drug in enough amount. In matrix tablets F6, the release of drug shows NLT 80%. So, the formulation F6 have been considered as suitable for the SR tablet of Darunavir and Ritonavir. Tablets were also evaluated though Quality by Design (QbD) method.

Abstract 10372: A Clinical Drug-Drug Interaction Study of Imb-1018972, a Novel Investigational Cardiac Mitotrope in Phase 2 Development for the Treatment of Myocardial Ischemia and Hypertrophic Cardiomyopathy

Background: IMB-1018972 (IMB-101) is a novel mitotropic agent designed to increase myocardial metabolic efficiency by shifting substrate utilization towards glucose through reducing fatty acid oxidation (inhibiting 3-ketoacyl CoA thiolase), thereby generating more ATP per unit of oxygen consumed. IMB-101 is hydrolyzed to IMB-1028814 (IMB-102, the active moiety) which is further metabolized with ~60% forming trimetazidine (TMZ). In vitro cytochrome P450 (CYP) studies reveal IMB-102 to be metabolized by multiple CYPs with CYP2C19 and CYP2D6 potentially comprising a major portion of its clearance and formation of TMZ. IMB-101 is under evaluation in Phase 2 studies in stable CAD, non-obstructive HCM &amp; T2DM, indications for which patients often take multiple medications concurrently. Aim: To evaluate the drug-drug interaction (DDI) potential of IMB-101 in healthy subjects. Methods: A fixed sequence crossover study conducted in 3 parts evaluating the effect of: 1) multiple dose oral (PO) IMB-101 on the single dose PK of PO CYP3A4 (midazolam) and CYP2C8 (repaglinide) substrates (n=23); multiple doses of strong inhibitors of 2) CYP2D6 (paroxetine) or 3) CYP2C19 (fluvoxamine) on the single dose PK of PO IMB-101 (n=14 each). Results: 1) Weak inhibition of CYP2C8 by IMB-101 based on AUC of repaglinide but none based on its Cmax. Weak inhibition of CYP3A4 by IMB-101 based on AUC and Cmax of midazolam. 2) Limited involvement of CYP2D6 in the metabolism of IMB-102 to metabolites other than TMZ based on IMB-102 AUC and Cmax when given with paroxetine. 3) A major role for CYP2C19 in the metabolism of IMB-102 to TMZ in vivo evidenced by increased IMB-102 exposure and reduced TMZ exposure when given with fluvoxamine. Based on the summation of AUCs for the active entities (IMB-102 and TMZ), exposure is unchanged with co-administration of fluvoxamine suggesting no IMB-101 dose adjustment is needed with concurrent strong CYP2C19 inhibition. Conclusions: IMB-101 does not result in clinically significant inhibition of CYP3A4 or 2C8 isoenzymes and its metabolites are not clinically relevant CYP2D6 substrates. These findings support the administration of IMB-101 with commonly used cardiovascular medications without a significant risk of DDI or requirement for dose alterations.

Bempedoic acid: A nonstatin drug for the management of hypercholesterolemia.

Bempedoic acid: A nonstatin drug for the management of hypercholesterolemia.

Formulation Development and Characterization of Darunavir and Ritonavir Sustained Release Tablets using Quality by Design Approach

Darunavir is a nonpeptidic inhibitor of protease and is primarily metabolized by cytochrome P450 3A (CYP3A) isoenzymes. It is usually coadministered with low-dose ritonavir (Darunavir/r). Ritonavir is an inhibitor of CYP3A isoenzymes and pharmacologically enhances Darunavir which leads to increased plasma concentrations of darunavir and allows for daily lower dose. Here, we have developed combination SR formulation of Darunavir and Ritonavir and evaluated. In vitro drug release of all formulations was carried out in dissolution medium 900ml of pH 3.0, 0.05 M Sodium Phosphate Buffer + 2% Tween 20 for 75 RPM USP II apparatus (paddle). The results shown that, all the formulations of matrix tablets shown the good release of drug from trialed formulations however all formulations were not releasing the drug in enough amount. In matrix tablets F6, the release of drug shows NLT 80%. So, the formulation F6 have been considered as suitable for the SR tablet of Darunavir and Ritonavir. Tablets were also evaluated though Quality by Design (QbD) method.

Formulation Development and Characterization of Darunavir and Ritonavir Immediate Release Tablets using Quality by Design approach

Darunavir is a nonpeptidic inhibitor of protease and is primarily metabolized by cytochrome P450 3A (CYP3A) isoenzymes. It is usually Coad ministered with low-dose ritonavir (Darunavir/r). Ritonavir is an inhibitor of CYP3A isoenzymes and pharmacologically enhances Darunavir which leads to increased plasma concentrations of darunavir and allows for daily lower dose. Here, we have developed combination IR formulation of Darunavir and Ritonavir and evaluated. In vitro drug release of all formulations was carried out in dissolution medium 900ml of pH 3.0 0.05 M Sodium Phosphate Buffer + 2% Tween 20 for 75 Min USP II apparatus (paddle). The results shown that, all the formulations of matrix tablets shown the good release of drug from trialed formulations however all formulations were not releasing the drug in enough amount. In matrix tablets F8, the release of drug shows 99%. So, the formulation F8 has been considered as suitable for the immediate release of Darunavir and Ritonavir. Tablets were also evaluated for physic chemical properties, dissolution studies and though Quality by Design (QbD) method.

Papaverine, a Phosphodiesterase 10A Inhibitor, Ameliorates Quinolinic Acid-Induced Synaptotoxicity in Human Cortical Neurons.

Phosphodiesterase-10A (PDE10A) hydrolyse the secondary messengers cGMP and cAMP, two molecules playing important roles in neurodevelopment and brain functions. PDE10A is associated to progression of neurodegenerative diseases like Alzheimer's, Parkinson's, Huntington's diseases, and a critical role in cognitive functions. The present study was undertaken to determine the possible neuroprotective effects and the associated mechanism of papaverine (PAP), a PDE10A isoenzyme inhibitor, against quinolinic acid (QUIN)-induced excitotoxicity using human primary cortical neurons. Cytotoxicity potential of PAP was analysed using MTS assay. Reactive oxygen species (ROS) and mitochondrial membrane potential were measured by DCF-DA and JC10 staining, respectively. Caspase 3/7 and cAMP levels were measured using ELISA kits. Effect of PAP on the CREB, BNDF and synaptic proteins such as SAP-97, synaptophysin, synapsin-I, and PSD-95 expression was analysed by Western blot. Pre-treatment with PAP increased intracellular cAMP and nicotinamide adenine dinucleotide (NAD+) levels, restored mitochondrial membrane potential (ΔΨm), and decreased ROS and caspase 3/7 content in QUIN exposed neurons. PAP up-regulated CREB and BDNF, and synaptic protein expression. In summary, these data indicate that PDE10A is involved in QUIN-mediated synaptotoxicity and its inhibition elicit neuroprotection by reducing the oxidative stress and protecting synaptic proteins via up-regulation of cAMP signalling cascade.