A physiologically based pharmacokinetic (PBPK) model of selegiline (SEL), and its metabolites, was developed in silico to evaluate the disposition differences between healthy and special populations. SEL is metabolized to methamphetamine (MAP) and desmethyl selegiline (DMS) by several CYP enzymes. CYP2D6 metabolizes the conversion of MAP to amphetamine (AMP), while CYP2B6 and CYP3A4 predominantly mediate the conversion of DMS to AMP. The overall prediction error in simulated PK, using the developed PBPK model, was within 0.5–1.5-fold after intravenous and transdermal dosing in healthy and elderly populations. Simulation results generated in the special populations demonstrated that a decrease in cardiac output is a potential covariate that affects the SEL exposure in renally impaired (RI) and hepatic impaired (HI) subjects. A decrease in CYP2D6 levels increased the systemic exposure of MAP. DMS exposure increased due to a reduction in the abundance of CYP2B6 and CYP3A4 in RI and HI subjects. In addition, an increase in the exposure of the primary metabolites decreased the exposure of AMP. No significant difference between the adult and adolescent populations, in terms of PK, were observed. The current PBPK model predictions indicate that subjects with HI or RI may require closer clinical monitoring to identify any untoward effects associated with the administration of transdermal SEL patch.

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Taken together, CPMD-6d dihydrochloride exhibits all properties to be positioned as a novel molecule of interest for treatment of tuberculosis. Graphical abstract: [Formula: see text].

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The present study was designed to investigate the oral bioavailability, metabolism, tissue disposition and excretion of 16α-hydroxycleroda-3, 13(14) Z -dien-15, 16-olide (4655K-09), a novel HMG-CoA reductase inhibitor in male Sprague Dawley (SD) rats. Tissue distribution, oral bioavailability and excretion studies of 4655K-09 were carried out in male SD rats through oral administration at active dose of 25 mg/kg. In vitro metabolism studies were carried out in different rat tissues S9 fractions to evaluate primary organs responsible for conversion of parent 4655K-09 to its major active metabolite K-9T. The quantification of both parent and metabolite in different biological matrices was performed using LC-MS/MS method. The oral bioavailability of 4655K-09 was found to be 30% in male SD rats. The biodistribution study was illustrated in terms of tissue to plasma area under curve (AUC) ratio (K) revealed the preferential distribution of 4655K-09 and K-9T to target site, i.e. liver. In vitro tissue S9 fraction stability assay demonstrated the rapid and extensive metabolic conversion of 4655K-09 to K-9T, primarily through liver and kidney. Very low amount of parent and metabolite were excreted unchanged in urine and faeces. The present studies established 4655K-09 bioavailability, tissue disposition, excretion and tissue-specific metabolic conversion to K-9T which could assist in its further development as antihyperlipidemic drug.

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