Drug metabolism letters最新文献

{"title":"The role of plant-based products in the prevention of neurological complications.","authors":"Ankul Singh S, Chitra V","doi":"10.2174/1872312815666220413095159","DOIUrl":"10.2174/1872312815666220413095159","url":null,"abstract":"<p><strong>Background: </strong>Neurological complications are most likely to be fatal and cause loss of ability to function or care for self. These include Alzheimer's disease and cognitive impairment. The main aim of the review is to determine the effects of various drugs and their cognitive risk with the need to opt for herbal therapy as an adjuvant in treating neurological conditions like Alzheimer's disease with lesser-known side effects. The Methodology: Involved a detailed literature survey which was performed through an online database, such as Science Direct, Google Scholar, Scopus, Cochrane, and PubMed. The study included randomized trials and original research conducted by herbal supplements on animal models to assess expression of upregulation of signalling pathways. Various studies involved in treating dementia, neurological disorders, Alzheimer disease, cognitive dysfunction were included.</p><p><strong>Results: </strong>Found that various studies involved plant-based products were showing improvement in prevention of disease and signalling pathways with lesser-known side effects.</p><p><strong>Conclusion: </strong>It was observed that plant-based products play a major role in the prevention of neurological complications. Herbal medicines could most suitably prevent Alzheimer's risk with less known side effects in contrast with the existing treatment patterns. However, to improve the utility of herbal medicines, more evidences from in vitro, in vivo, and clinical trials need to be addressed.</p>","PeriodicalId":11339,"journal":{"name":"Drug metabolism letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42914566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Impact of the Coronavirus (COVID-19) Infection on the Drug-Metabolizing Enzymes Cytochrome P450s.","authors":"Imadeldin Elfaki","doi":"10.2174/1872312815666220331142046","DOIUrl":"10.2174/1872312815666220331142046","url":null,"abstract":"<p><p>Coronaviruses cause disease in human and animals. In 2019 a novel coronavirus was first characterized in Wuhan, China. It causes acute respiratory disease and designated the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or COVID-19. The COVID-19 spread to all cities of China, and in 2020 to the whole world. Patients with COVID-19 may recover without medical treatment. However, some patients need medical care. The Cytochrome p450s (CYP450s) are large superfamily of enzymes catalyze the metabolism of endogenous substrates and xenobiotics. CYP450s catalyze the biotransformation of 80% of the drug in clinical use. The CYP450 present in liver, lungs, intestine and other tissues. COVID-19 has been reported to decrease the activity of certain isoforms of CYP450s in an isoform specific manner. Furthermore, the COVID-19 infection decreases the liver functions including the drug clearance or detoxification medicated by the CYP450s. The healthcare providers should be aware of this disease-drug interaction when prescribing drugs for treatment of COVID-19 and other comorbidities.</p>","PeriodicalId":11339,"journal":{"name":"Drug metabolism letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43011771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ZY12201, A Potent TGR5 Agonist: Identification of a Novel Pan CYP450 Inhibitor Tool Compound for In-Vitro Assessment.","authors":"Poonam Giri, Lakshmikant Gupta, Anil Rathod, Vipul Joshi, Shyamkumar Giri, Nirmal Patel, Sameer Agarwal, Mukul R Jain","doi":"10.2174/1872312815666220315145945","DOIUrl":"10.2174/1872312815666220315145945","url":null,"abstract":"<p><strong>Background: </strong>Identification of clinical drug-drug interaction (DDI) risk is an important aspect of drug discovery and development owing to poly-pharmacy in present-day clinical therapy. Drug metabolizing enzymes (DME) plays important role in the efficacy and safety of drug candidates. Hence evaluation of a New Chemical Entity (NCE) as a victim or perpetrator is very crucial for DDI risk mitigation. ZY12201 (2-((2-(4-(1H-imidazol-1-yl) phenoxy) ethyl) thio)-5-(2-(3, 4- dimethoxy phenyl) propane-2-yl)-1-(4-fluorophenyl)-1H-imidazole) is a novel and potent Takeda-G-protein-receptor-5 (TGR-5) agonist. ZY12201 was evaluated in-vitro to investigate the DDI liabilities.</p><p><strong>Objective: </strong>The key objective was to evaluate the CYP inhibition potential of ZY12201 for an opportunity to use it as a tool compound for pan CYP inhibition activities.</p><p><strong>Method: </strong>In-vitro drug metabolizing enzymes (DME) inhibition potential of ZY12201 was evaluated against major CYP isoforms (1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4/5), aldehyde oxidase (AO), monoamine oxidase (MAO), and flavin-containing monooxygenase (FMO in human liver cytosol/mitochondrial preparation/ microsomes using probe substrates and Liquid Chromatography with tandem mass spectrometry (LC-MS-MS) method.</p><p><strong>Results: </strong>The study conducted on ZY12201 at 100 µM ZY12201 was found to reduce the metabolism of vanillin (AO probe substrate), tryptamine (MAO probe substrate), and benzydamine (FMO probe substrate) by 49.2%, 14.7%, and 34.9%, respectively. ZY12201 Ki values were 0.38, 0.25, 0.07, 0.01, 0.06, 0.02, 7.13, 0.03 and 0.003 μM for CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4/5 (substrate: testosterone) and CYP3A4/5 (substrate: midazolam), respectively. Time-dependant CYP inhibition potential of ZY12201 was assessed against CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4/5 and no apparent IC50 shift was observed.</p><p><strong>Conclusions: </strong>ZY12201, at 100 µM concentration showed low inhibition potential of AO, MAO, and FMO. ZY12201 was found as a potent inhibitor of CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4/5 while moderately inhibits to CYP2E1. Inhibition of CYP1A2, CYP2B6, CYP2C19, and CYP2E1 by ZY12201 was competitive, while inhibition of CYP2C8, CYP2C9, CYP2D6, and CYP3A4/5 was of mixed-mode. ZY12201 is a non-time-dependent inhibitor of CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4/5. In summary, the reported Ki values unequivocally support that ZY12201 has a high potential to inhibit all major CYP isoforms. ZY12201 can be effectively used as a tool compound for in-vitro evaluation of CYP-based metabolic contribution to total drug clearance in the lead optimization stage of Drug Discovery Research.</p>","PeriodicalId":11339,"journal":{"name":"Drug metabolism letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46307719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Meet the Editorial Board Member","authors":"H. Yamazaki","doi":"10.2174/187231281402211122155035","DOIUrl":"https://doi.org/10.2174/187231281402211122155035","url":null,"abstract":"","PeriodicalId":11339,"journal":{"name":"Drug metabolism letters","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45077612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Amorphous Solid Dispersion Based Oral Disintegrating Film of Ezetimibe: Development and Evaluation.","authors":"Preethi Sudheer,&nbsp;Sangam Shrestha,&nbsp;Kavitha A Narayana","doi":"10.2174/1872312814666200901182517","DOIUrl":"https://doi.org/10.2174/1872312814666200901182517","url":null,"abstract":"<p><strong>Background: </strong>Ezetimibe is a cholesterol-lowering agent with an oral bioavailability of 50% by virtue of its poor solubility and extensive hepatic and intestinal metabolism.</p><p><strong>Objective: </strong>The study aimed to overcome low bioavailability issues of ezetimibe by formulating an oral disintegrating film.</p><p><strong>Methods: </strong>The low solubility of ezetimibe was undertaken, preparing solid dispersions using mannitol, β-cyclodextrin, and urea. The mannitol solid dispersion assimilated oral disintegrating film was prepared and optimized using 2³ factorial design, where the concentration of film formers hydroxypropyl methylcellulose (K5& K15) (X1and X2) and super disintegrant, sodium starch glycolate (X3) was used as factors on the response disintegration time (Y). The films were evaluated for physical properties, time of disintegration, and drug release profiles.</p><p><strong>Results: </strong>Mannitol solid dispersion (1:2 ratio) based on the superior drug content, solubility and in vitro release profile was preferred in film formation. The low crystalline nature of the solid dispersion was very evident by the absence of prominent peaks in the X-Ray diffraction pattern and the reduced peak intensity of melting endotherms. The correlation coefficient (R2) and statistical parameter analysis of variance specify the implication of linear factors on responses, which is apparent from confidence intervals (P-values) less than 0.05. The in vitro release profile of all the eight formulations (F1-F8) in a phosphate buffer solution of pH 6.8 revealed a significant increment in comparison to ezetimibe.</p><p><strong>Conclusion: </strong>The study revealed that the formulation approach could overcome the biopharmaceutical challenge of solubility as well as low bioavailability issues of ezetimibe.</p>","PeriodicalId":11339,"journal":{"name":"Drug metabolism letters","volume":"14 1","pages":"66-79"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38336461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative <i>In vitro</i> Metabolism of Enflicoxib in Dogs, Rats, and Humans: Main Metabolites and Proposed Metabolic Pathways.","authors":"Josep Solà,&nbsp;Àngel Menargues,&nbsp;Josep Homedes,&nbsp;Marta Salichs,&nbsp;Maria Teresa Serafini,&nbsp;Gregorio Encina","doi":"10.2174/1872312814666211209161933","DOIUrl":"https://doi.org/10.2174/1872312814666211209161933","url":null,"abstract":"<p><strong>Background: </strong>Enflicoxib is a non-steroidal anti-inflammatory drug of the coxib family characterized by a long-lasting pharmacological activity that has been attributed to its active metabolite E-6132.</p><p><strong>Objectives: </strong>The aim of this work was to explore enflicoxib biotransformation In vitro in humans, rats and dogs, and to determine its metabolic pathways.</p><p><strong>Methods: </strong>Different In vitro test systems were used, including hepatocytes and liver and non-hepatic microsomes. The samples were incubated with enflicoxib and/or any of its metabolites at 37°C for different times depending on the test system. The analyses were performed by liquid chromatography coupled with either radioactivity detection or high-resolution mass spectrometry.</p><p><strong>Results: </strong>Enflicoxib was efficiently metabolized by cytochrome P-450 into three main phase I metabolites: M8, E-6132, and M7. The non-active hydroxy-pyrazoline metabolite M8 accounted for most of the fraction metabolized in all the three species. The active pyrazol metabolite E-6132 showed a slow formation rate, especially in dogs, whereas metabolite M7 was a secondary metabolite formed by oxidation of M8. In hepatocytes, diverse phase II metabolite conjugates were formed, including enflicoxib glucuronide, M8 glucuronide, E-6132 glucuronide, M7 glucuronide, and M7 sulfate. Metabolite E-6132 was most probably eliminated by a unique glucuronidation reaction at a very low rate.</p><p><strong>Conclusion: </strong>The phase I metabolism of enflicoxib was qualitatively very similar among rats, humans and dogs. The low formation and glucuronidation rates of the active enflicoxib metabolite E-6132 in dogs are postulated as key factors underlying the mechanism of its long-lasting pharmacokinetics and enflicoxib's overall sustained efficacy.</p>","PeriodicalId":11339,"journal":{"name":"Drug metabolism letters","volume":"14 3","pages":"206-218"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/77/da/DML-14-206.PMC9175088.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39799404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ameliorative Effect of Acetyl L-carnitine in Alzheimer's Disease via Downregulating of Homocysteine Levels in Hyperhomocysteinemia Induced Cognitive Deficit in Mouse Model.","authors":"Nisha Verma,&nbsp;Jeetendra Kumar Gupta,&nbsp;Krishna Kumar Varshney,&nbsp;Rajnish Srivastava","doi":"10.2174/1872312814666211209102136","DOIUrl":"https://doi.org/10.2174/1872312814666211209102136","url":null,"abstract":"<p><strong>Aims: </strong>The study was aimed at exploring the role of Acetyl L-Carnitine supplementation attenuating dementia and degradation of cognitive abilities in Hyperhomocysteinemia induced AD manifestations in the mouse model.</p><p><strong>Background: </strong>Alzheimer's disease (AD) is a neurological disorder that is marked by dementia, and degradation of cognitive abilities. There is great popularity gained by natural supplements as the treatment for AD, due to the higher toxicities of synthetic drugs. Hyperhomocysteinemia causes excitotoxicity to the cortical neurons, which brought us to the point that amino acids possibly have a role in causing cholinergic deformities, which are an important etiological parameter in AD. Acetyl L-Carnitine a methyl donor with the presence of three chemically reactive methyl groups linked to a nitrogen atom was found to possess neuroprotective activity against experimental models of AD.</p><p><strong>Objective: </strong>The objective of the present investigation was to investigate and evaluate the pharmacological effect of Acetyl L-Carnitine against hyperhomocysteinemia induced Alzheimer's disease (AD) in the mouse model.</p><p><strong>Materials and methods: </strong>The animals were divided into normal control (vehicle-treated), HHcy (dl-Homocysteine thiolactone treated) negative control, test group i.e., low dose (50mg/kg, p.o) of acetyl L-carnitine (L-ALC), high dose (100mg/kg,p.o) of acetyl L-carnitine (H-ALC), L-ALC+ SOV (Sodium orthovanadate) and H-ALC+SOV. HHcy was induced by administration of dl-Homocysteine thiolactone (dl-HCT; 1 g/kg, p.o.) on day-1 to day-15 of experimental schedule to all animals except normal control. The changes in the behaviour pattern of the animals due to neuroinflammation, and cholinergic dysfunction were examined in rotarod, novel objective recognition, passive avoidance, elevated plus maze, and morris water maze analysis. Biochemical investigation includes the estimation of total homocysteine (tHcy), Creatinine Kinase (CK), Acetylcholinesterase (AChE), thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and IL-6 and TNF-α.</p><p><strong>Results: </strong>Supplementation of ALC in mouse considerably lowered the HHcy-induced AD manifestations in the experimental animals. It was found that ALC and SOV successfully diminished the behaviour abnormalities and lessened the Hcy-induced alteration in systemic Hcy levels, CK activity, and cholinergic dysfunction with improved bioenergetics in the Prefrontal cortex of the mice.</p><p><strong>Conclusion: </strong>ALC was found to improve the HHcy-induced cognitive disabilities which was found to be associated with the decreased systemic levels of Hcy, CK, and cholinergic abnormalities. It also combats the oxidative stress-induced neuroinflammation with diminished pro-inflammatory markers in the pre frontal cortex. The outcomes collectively indicate ALC's potential to be used as a supplementation in the ","PeriodicalId":11339,"journal":{"name":"Drug metabolism letters","volume":"14 3","pages":"219-231"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39799405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pharmacokinetics Parameters of Diagoxin among Saudi Patients in Qassim Region, Saudi Arabia.","authors":"Abdulaziz S Allihimy,&nbsp;Ahmad A Almeman,&nbsp;Nassar A Alnassar,&nbsp;Jihad Almadhi","doi":"10.2174/1872312814666210506121637","DOIUrl":"https://doi.org/10.2174/1872312814666210506121637","url":null,"abstract":"<p><strong>Background: </strong>The pharmacodynamic effects of digoxin are susceptible to multiple factors, most notably, heart uptake of the digoxin dose and its concentration in the serum. Another important factor to mention is the renal function state of an individual.</p><p><strong>Objective: </strong>In this study, we aimed to develop a simple algorithm based on subsets of clinically relevant information, which will help to personalize digoxin based on pharmacokinetic (PK) approach which can help in marketing the appropriate utilization of this medication.</p><p><strong>Methods: </strong>This was a retrospective chart review and analysis of 48 patients who were admitted to the Drug and Poison Information center in Buraidah, Saudi Arabia, between January 2016 and April 2019. All pharmacokinetic parameters were added according to the C-peaks and C-troughs. MONOLiX® was used for data pharmacokinetic analysis.</p><p><strong>Results: </strong>Twenty-seven (56%) were males and twenty-one (44%) were females with an average age of 63.6 years across both genders. The mean volume of distribution was 496.6 litres with an average clearance of 6.6 L/h. For females, their average volume of distribution was slightly higher than that for males (526 litres compared to 473 litres). In addition, the clearance rate between both genders showed a 2.1 litre/hour discrepancy (7.8 L/h for females compared to 5.7 L/h for males).</p><p><strong>Conclusion: </strong>In order to individualize the digoxin dosage regimens, this model can be used to predict digoxin serum concentration. Further studies are needed to clarify the effects of nutritional status and co-administration of medications on digoxin pharmacokinetics.</p>","PeriodicalId":11339,"journal":{"name":"Drug metabolism letters","volume":"14 2","pages":"137-140"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38967466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Link Between Conventional and Novel Anti-Cancer Therapeutics with Thrombotic Microangiopathy.","authors":"Carmen E Cervantes,&nbsp;Sam Kant,&nbsp;Mohamed G Atta","doi":"10.2174/1872312814666210716141633","DOIUrl":"https://doi.org/10.2174/1872312814666210716141633","url":null,"abstract":"BACKGROUND\u0000Kidney disease associated with cancer and anti-cancer therapies has been increasingly recognized in the field of Onco-nephrology. In particular, drug-induced nephrotoxicity has necessary implications since most chemotherapeutic agents have nephrotoxic potential. Also, standard creatinine clearance methods used to measure kidney function have been questioned in cancer patients due to factors like low muscle mass and poor nutritional status. Overestimations of the glomerular filtration rate not only increase the nephrotoxic potential of different agents but also can further limit the use of first-line therapies.\u0000\u0000\u0000OBJECTIVE\u0000This review covers drug-induced thrombotic microangiopathy explicitly. It has two pathophysiologic mechanisms, including immune or idiosyncratic reactions and non-immune or dose-dependent ones.\u0000\u0000\u0000CONCLUSION\u0000As novel cancer therapies are developed, it is paramount to understand better conventional and novel chemotherapeutic agents and their role in kidney disease.","PeriodicalId":11339,"journal":{"name":"Drug metabolism letters","volume":"14 2","pages":"97-105"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39198253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pharmacokinetics of Darolutamide, its Diastereomers and Active Metabolite in the Mouse: Response to Saini NK et al. (2020).","authors":"Pirjo Nykänen,&nbsp;Timo Korjamo,&nbsp;Hille Gieschen,&nbsp;Christian Zurth,&nbsp;Mikko Koskinen","doi":"10.2174/1872312814666201112121129","DOIUrl":"https://doi.org/10.2174/1872312814666201112121129","url":null,"abstract":"<p><strong>Background: </strong>Saini et al. recently investigated the pharmacokinetics of darolutamide and its diastereomers in vitro and in vivo in Balb/c mice, reporting higher levels of (S,S)-darolutamide than (S,R)-darolutamide following intravenous or oral dosing, and interconversion of (S,R)-darolutamide to (S,S)-darolutamide.</p><p><strong>Objective: </strong>To present our in vitro and in vivo studies of darolutamide pharmacokinetics in mice, which contrast with the findings of Saini et al. Methods: Nude male Balb/c mice were orally dosed for 7 days with 25, 50, or 100 mg/kg of darolutamide twice daily. Pharmacokinetic parameters in plasma and tissue samples were assessed by liquid chromatography-tandem mass spectrometry. Metabolism and interconversion of darolutamide and its diastereomers were investigated in cryopreserved Balb/c mouse hepatocytes. Protein binding was determined in plasma samples by equilibrium dialysis.</p><p><strong>Results: </strong>On day 7, C_max was reached 30 min after the last dose. Rapid formation and greater exposure of keto-darolutamide versus darolutamide were observed. Plasma exposure of (S,R)-darolutamide was 3-5-fold higher than that of (S,S)-darolutamide. The fraction of unbound keto-darolutamide was almost 6-fold lower than for darolutamide. In mouse hepatocytes, the conversion of (S,S)- to (S,R)-darolutamide was observed, but the conversion of (S,R)- to (S,S)-darolutamide was not detectable. Back-formation of keto-darolutamide to both diastereomers occurred at low levels.</p><p><strong>Conclusion: </strong>The darolutamide diastereomer ratio changes upon administration in mice and other species due to interconversion through keto-darolutamide. This is not considered clinically relevant since both diastereomers and keto- darolutamide are pharmacologically similar in vitro. Based on the high protein binding of keto-darolutamide, its contribution in vivo in humans is considered low.</p>","PeriodicalId":11339,"journal":{"name":"Drug metabolism letters","volume":"14 1","pages":"9-16"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38596460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}