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Polyphenolic compounds (including flavonoids, chalcones, phenolic acids, and furanocoumarins) represent a common part of our diet, but are also the active ingredients of several dietary supplements and/or medications. These compounds undergo extensive metabolism by human biotransformation enzymes and the microbial flora of the colon. CYP2D6 enzyme metabolizes approximately 25% of the drugs, some of which has narrow therapeutic window. Therefore, its inhibition can lead to the development of pharmacokinetic interactions and the disruption of drug therapy. In this study, the inhibitory effects of 17 plant-derived compounds and 19 colonic flavonoid metabolites on CYP2D6 were examined, employing two assays with different test substrates. The O-demethylation of dextromethorphan was tested employing CypExpress 2D6 kit coupled to HPLC analysis; while the O-demethylation of another CYP2D6 specific substrate (AMMC) was investigated in a plate reader assay with BioVision Fluorometric CYP2D6 kit. Interestingly, some compounds (e.g., bergamottin) inhibited both dextromethorphan and AMMC demethylation; however, certain substances proved to be inhibitors only in one of the assays applied. Our results demonstrate that some polyphenols and colonic metabolites are inhibitors of CYP2D6-catalyzed reactions. Nevertheless, the inhibitory effects showed strong substrate dependence.

The impact of inhibitor depletion on the determination of shifted IC 50 (IC50 determined after 30 minutes of preincubation with inhibitor) is examined. In addition, IC50-shift data are analyzed using a mechanistic model that incorporates the processes of inhibitor depletion, as well as reversible and time-dependent inhibition. Anomalies such as a smaller-than-expected shift in IC50 and even increases in IC50 with preincubation were explained by the depletion of inhibitor during the preincubation. The IC50-shift assay remains a viable approach to characterizing a wide range of reversible and time-dependent inhibitors. However, as with more traditional time-dependent inactivation methods, it is recommended that IC50-shift experimental data be interpreted with some knowledge of the magnitude of inhibitor depletion. For the most realistic classification of time-dependent inhibitors using IC 50-shift methods, shifted IC50 should be calculated using observed inhibitor concentrations at the end of the incubation rather than nominal inhibitor concentrations. Finally, a mechanistic model that includes key processes, such as competitive inhibition, enzyme inactivation, and inhibitor depletion, can be used to describe accurately the observed IC50 and shifted IC50 curves. For compounds showing an IC50 fold shift >1.5 based on the observed inhibitor concentrations, reanalyzing the IC50-shift data using the mechanistic model appeared to allow for reasonable estimation of Ki, KI, and kinact directly from the IC50 shift experiments.

Curcumin (diferuloylmethane) is a major yellow pigment and dietary component derived from Curcuma longa. It has potent anti-inflammatory, anticarcinogenic, antioxidant and chemoprotective activities among others. We studied the interactions of curcumin, a mixture of its decomposition products, and four of its individually identified decomposition products (vanillin, vanillic acid, ferulic aldehyde and ferulic acid) on five major human drug-metabolizing cytochrome P450s (CYPs). Curcumin inhibited CYP1A2 (IC50, 40.0 μM), CYP3A4 (IC50, 16.3 μM), CYP2D6 (IC50, 50.3 μM), CYP2C9 (IC50, 4.3 μM) and CYP2B6 (IC50, 24.5 μM). Curcumin showed a competitive type of inhibition towards CYP1A2, CYP3A4 and CYP2B6, whereas a non-competitive type of inhibition was observed with respect to CYP2D6 and CYP2C9. The inhibitory activity towards CYP3A4, shown by curcumin may have implications for drug-drug interactions in the intestines, in case of high exposure of the intestines to curcumin upon oral administration. In spite of the significant inhibitory activities shown towards the major CYPs in vitro, it remains to be established, whether curcumin will cause significant drug-drug interactions in the liver, given the reported low systemic exposure of the liver to curcumin. The decomposition products of curcumin showed no significant inhibitory activities towards the CYPs investigated, and therefore, are not likely to cause drug-drug interactions at the level of CYPs.

By mimicking the role of human liver P450 monooxygenases, fungal unspecific peroxygenases (UPOs) can perform a range of highly selective oxyfunctionalization reactions on pharmacological compounds, including O-dealkylations and hydroxylations, thereby simulating drug metabolism. Here we have benchmarked human drug metabolite (HDM) synthesis by several evolved UPO mutants, focusing on dextromethorphan, naproxen and tolbutamide. The HDM from dextromethorphan was prepared at the semi-preparative scale as a proof of production. The structural analysis of mutations involved in the synthesis of HDMs highlights the heme access channel as the main feature on which to focus when designing evolved UPOs. These variants are becoming emergent tools for the cost-effective synthesis of HDMs from next-generation drugs.

The inhibitory effects of dihydroquinidine, quinidine and several quinidine metabolites on cytochrome P450 2D6 (CYP2D6) activity were examined. CYP2D6 heterologously expressed in yeast cells O-demethylated dextromethorphan with a mean K(m) of 5.4 μM and a V(max) of 0.47 nmol/min/nmol. Quinidine and dihydroquinidine both potently inhibited CYP2D6 metabolic activity (mean K(i) = 0.027 and 0.013 μM, respectively) in yeast microsomes and in human liver microsomes. The metabolites, 3-hydroxyquinidine, O-desmethylquinidine and quinidine N-oxide also inhibited CYP2D6, but their K(i) values (0.43 to 2.3 μM) were one to two orders of magnitude weaker than the values for quinidine and dihydroquinidine. There was a trend towards an inverse relationship between K(i) and lipophilicity (r = -0.90, N = 5, P = 0.07), as determined by the retention-time parameter k' using reverse-phase HPLC. Thus, although the metabolites of quinidine have the capacity to inhibit CYP2D6 activity, quinidine and the impurity dihydroquinidine are the important inhibitors of CYP2D6.

1. Recombinant human cytochrome P450 (rhCYP) has become an important screening model in drug metabolism studies due to the high cost of human and animal hepatic tissue. Until now, rhCYPs have been evaluated and used as separate forms, but a mixture of CYP forms comparable with the human liver could be of value in early drug discovery. 2. In the present study, rhCYP2C9, rhCYP2D6 and rhCYP3A4 co-expressed with reductase in Escerichia coli were mixed and evaluated with regards to kinetic properties (Km and Vmax). Furthermore, antioxidant was added to investigate whether a free radical scavenger would affect the kinetic parameters. Results were compared with data obtained in human liver microsomes (HLM). 3. Results showed a good correlation between mixed rhCYP data and HLM data for Km and Vmax. Km varied m for CYP2D6 varied up to 4.5-fold. Vmax differed up to 3-fold between matrices for the CYP forms investigated. However, the discrepancy in Vmax may depend on the anticipated level of each form in HLM. The addition of antioxidant increased Vmax for CYP2C9 and CYP2D6 by 75 and 50%, respectively, whereas Vmax for CYP3A4 was unchanged. 4. In conclusion, the rhCYP mixture shows promising results as a predictor of CYP kinetic parameters. Furthermore, addition of antioxidant can in certain cases increase catalytic activity.

Δ9-Tetrahydrocannabinol, cannabidiol (CBD), and cannabinol are the three major cannabinoids contained in marijuana, which are devoid of nitrogen atoms in their structures. In this study, we investigated the inhibitory effects of the major phytocannabinoids on the catalytic activity of human CYP2D6. These major cannabinoids inhibited the 3-[2-(N,N-diethyl-N- methylammonium)ethyl]-7-methoxy-4-methylcoumarin (AMMC) and dextromethorphan O-demethylase activities of recombinant CYP2D6 and pooled human liver microsomes in a concentration-dependent manner (IC50 =4.01-24.9 μM), indicating the strongest inhibitory potency of CBD. However, these cannabinoids showed no or weak metabolism-dependent inhibition. CBD competitively inhibited the CYP2D6 activities with the apparent Ki values of 1.16 to 2.69 μM. To clarify the structural requirement for CBD-mediated CYP2D6 inhibition, effects of CBD-related compounds on the AMMC O-demethylase activity of recombinant CYP2D6 were examined. Olivetol (IC50 =7.21 μM) inhibited CYP2D6 activity as potently as CBD did (IC50 =6.52 μM), whereas d-limonene did not show any inhibitory effect. Pentylbenzene failed to inhibit CYP2D6 activity. Furthermore, neither monomethyl nor dimethyl ethers of CBD inhibited the activity. Cannabidivarin having a propyl side chain inhibited CYP2D6 activity; its inhibitory effect (IC50 = 10.2 μM) was less potent than that of CBD. On the other hand, orcinol and resorcinol showed lack of inhibition. The inhibitory effect of CBD on CYP2D6 activity was more potent than those of 16 compounds without nitrogen atoms tested, such as progesterone. These results indicated that CBD caused potent direct CYP2D6 inhibition, in which two phenolic hydroxyl groups and the pentyl side chain of CBD may play important roles. Copyright

Treatment of dextromethorphan 1 with various alkylating agents followed by base treatment led to Hoffman-type elimination reactions to produce a series of tricyclic derivatives, 6. These derivatives were characterized in vitro as sigma-1 receptor ligands.

We synthesized a series of compounds that are modified in positions 3 and 17 of the morphinan ring system, with the intention of developing ideal anticonvulsant agents. We examined the effects of these compounds on kainic acid (KA)-induced seizures, and on locomotor patterns in rats. We found that compounds 5, 6, and 8 exhibit novel anticonvulsant effects, with negligible psychotropic effects.

H2O2 can be accepted by several peroxygenases as a clean oxidant, able to supply both the necessary electrons and oxygen atom at the same time. The biocatalysts, in turn, are able to catalyse an array of interesting oxygen insertion reactions at enantio- and regio-selectivities hard to attain with classical chemical methods. The sensitivity of most peroxygenases towards H2O2, however, requires this oxidant to be generated in situ. Here, we suggest the application of (modified) sulfite oxidases to couple the oxidation of sulfites to the reduction of oxygen. This enables us to use calcium sulfite, an industrial waste product from scrubbing flue gases, as an electron donor to reduce oxygen. This will supply the required peroxide in a controlled manner and enables us to perform these challenging reactions at the expense of simple salts.

Substituted analogs of dextromethorphan (DM) are disclosed, which are shown to have substantial binding affinity at both NMDA and sigma-1 receptors, and which are degraded by human liver enzymes more slowly than dextromethorphan. The analogs are useful as alternatives to dextromethorphan, and can provide the same benefits without requiring co-administration of a cytochrome P-450 enzyme inhibitor.

Inter-individual variability in pharmacokinetics and drug response is heavily influenced by single-nucleotide variants (SNVs) and copy-number variations (CNVs) in genes with importance for drug disposition. Nowadays, a plethora of studies implement next generation sequencing to capture rare and novel pharmacogenomic (PGx) variants that influence drug response. To address these issues, we present a comprehensive end-to-end analysis workflow, beginning from targeted PGx panel re-sequencing to in silico analysis pipelines and in vitro validation assays. Specifically, we show that novel pharmacogenetic missense variants that are predicted or putatively predicted to be functionally deleterious, significantly alter protein activity levels of CYP2D6 and CYP2C19 proteins. We further demonstrate that variant priorization pipelines tailored with functional in vitro validation assays provide supporting evidence for the deleterious effect of novel PGx variants. The proposed workflow could provide the basis for integrating next-generation sequencing for PGx testing into routine clinical practice.

A method for producing substantially pure levorphanol and related compounds, when compared to the conventional process, is provided. In particular, a method for producing substantially pure levorphanol tartrate dihydrate is described. Also described are compositions comprising levorphanol and related compounds, particularly compositions comprising levorphanol tartrate dihydrate, levomethorphan, and norlevorphanol in which the levomethorphan and norlevorphanol are present in the composition in reduced levels.

Hydralazine has been reported as a selective mechanism-based inactivator of aldehyde oxidase (AO) and it is widely used in the pharmaceutical industry for reaction phenotyping to estimate fraction metabolized by AO and to identify AO substrates. In this study, however, hydralazine was found to inhibit CYP1A2, 2B6, 2D6, and 3A in human suspension hepatocytes under reaction phenotyping assay conditions, at concentrations that chemically knocked out most of the AO activities (≥50 μM). Furthermore, hydralazine is a time-dependent inhibitor of CYP1A2. Based on these findings, precautions need to be taken when using hydralazine as an AO inhibitor for in vitro studies because fraction metabolized by AO is likely to be overestimated and the likelihood of false positives in identifying AO substrates increases.

Cytochromes P450 are major metabolic enzymes involved in the biotransformation of xenobiotics. The majority of xenobiotics are metabolized in the liver, in which the highest levels of cytochromes P450 are expressed. Flavonoids are natural compounds to which humans are exposed through everyday diet. In the previous study, selected flavonoid aglycones showed inhibition of CYP3A4 enzyme. Thus, the objective of this study was to determine if these flavonoids inhibit metabolic activity of CYP1A2, CYP2A6, CYP2C8, and CYP2D6 enzymes. For this purpose, the O-deethylation reaction of phenacetin was used for monitoring CYP1A2 enzyme activity, coumarin 7-hydroxylation for CYP2A6 enzyme activity, 6-α-hydroxylation of paclitaxel for CYP2C8 enzyme activity, and dextromethorphan O-demethylation for CYP2D6 enzyme activity. The generated metabolites were monitored by high-performance liquid chromatography coupled with diode array detection. Hesperetin, pinocembrin, chrysin, isorhamnetin, and morin inhibited CYP1A2 activity; apigenin, tangeretin, galangin, and isorhamnetin inhibited CYP2A6 activity; and chrysin, chrysin-dimethylether, and galangin inhibited CYP2C8. None of the analyzed flavonoids showed inhibition of CYP2D6. The flavonoids in this study were mainly reversible inhibitors of CYP1A2 and CYP2A6, while the inhibition of CYP2C8 was of mixed type (reversible and irreversible). The most prominent reversible inhibitor of CYP1A2 was chrysin, and this was confirmed by the docking study.

The invention relates to dextrorphan-derivatives, pharmaceutical compositions and pharmaceutical dosage forms containing such dextrorphan-derivatives as well as the use of those dextrorphan-derivatives and/or compositions for treating and preventing diseases and conditions in man and mammals.

Metabolites of new chemical entities can influence safety and efficacy of a molecule and often times need to be quantified in preclinical studies. However, synthetic standards of metabolites are very rarely available in early discovery. Alternate approaches such as biosynthesis need to be explored to generate these metabolites. Assessing the quantity and purity of these small amounts of metabolites with a nondestructive analytical procedure becomes crucial. Quantitative NMR becomes the method of choice for these samples. Recent advances in high-field NMR (>500 MHz) with the use of cryoprobe technology have helped to improve sensitivity for analysis of small microgram quantity of such samples. However, this type of NMR instrumentation is not routinely available in all laboratories. To analyze microgram quantities of metabolites on a routine basis with lower-resolution 400 MHz NMR instrument fitted with a broad band fluorine observe room temperature probe, a novel hybrid capillary tube setup was developed. To quantitate the metabolite in the sample, an artificial signal insertion for calculation of concentration observed (aSICCO) method that introduces an internally calibrated mathematical signal was used after acquiring the NMR spectrum. The linearity of aSICCO signal was established using ibuprofen as a model analyte. The limit of quantification of this procedure was 0.8 mM with 10 K scans that could be improved further with the increase in the number of scans. This procedure was used to quantify three metabolites—phenytoin from fosphenytoin, dextrophan from dextromethorphan, and 4-OH-diclofenac from diclofenac—and is suitable for minibiosynthesis of metabolites from in vitro systems.

Acetylshikonin is a biologically active compound with anti-cancer and anti-inflammatory activity, which is isolated from the roots of Lithospermum erythrorhizoma. An inhibitory effect of acetylshikonin against CYP2J2 activity was discovered recently. Based on this result, this study was expanded to evaluate the inhibitory effects of acetylshikonin against nine different cytochrome P450 (P450) isoforms in human liver microsomes (HLMs) using substrate cocktails incubation assay. Acetylshikonin showed a strong inhibitory effect against all P450s tested with IC50 values of 1.4–4.0 μ m. Pre-incubation of acetylshikonin with HLMs and NADPH did not alter the inhibition potency, indicating that acetylshikonin is not a mechanism-based inhibitor. SKF-525A, a widely used non-specific P450 inhibitor, had no inhibitory activity against CYP1A2, 2A6, 2E1 and 2J2, while it showed an inhibitory effect against CYP2B6, CYP2C19 and 2D6 with IC50 values of 2.5, 3.6 and 0.5 μ m, respectively. Our findings indicate that acetylshikonin may be a novel general P450 inhibitor, which could replace SKF-525A.

Bupropion is a widely used antidepressant and the recommended CYP2B6 probe drug. However, current understanding of bupropion elimination pathways is limited. Bupropion has three active circulating metabolites, OH-bupropion, threohydrobupropion, and erythrohydrobupropion, but together with bupropion these metabolites and their conjugates in urine represent only 23% of the dose, and the majority of the elimination pathways of bupropion result in uncharacterized metabolites. The aim of this study was to determine the structures of the uncharacterized bupropion metabolites using human clinical samples and in vitro incubations. Three new metabolites, 4′-OH-bupropion, erythro-4′-OH-hydrobupropion, and threo-4′-OH-hydrobupropion, were detected in human liver microsome incubations and were isolated from human urine. The structures of the metabolites were confirmed via comparison of UV absorbance, NMR spectra, and mass spectral data to those of the synthesized standards. In total, these metabolites represented 24% of the drug related material excreted in urine.

The invention relates to a method for the treatment of neuropsychiatric behavioral symptoms in patients with Alzheimer's Disease wherein the symptoms are selected from the group consisting of anxiety, agitation, aggression, depression, hallucination, memory loss, confusion, repetition, sleep issues, sun downing, suspicion, delusions, and wandering, comprising the step of administering to the patient an effective amount of a compound of Formula I, IA, IB, Table 1, preferably Compound-1, or a pharmaceutically acceptable salt thereof.

Nitrogen heterocycles are ubiquitous in natural products and pharmaceuticals. Herein, we disclose a nitrogen complexation strategy that employs a strong Bronsted acid (HBF4) or an azaphilic Lewis acid (BF3) to enable remote, non-directed C(sp3)-H oxidations of tertiary, secondary, and primary amine- and pyridine-containing molecules with tunable iron catalysts. Imides resist oxidation and promote remote functionalization.

1. Cytochrome P450 enzyme system is the most important contributor to oxidative metabolism of drugs. Modification, and more specifically inhibition, of this system is an important determinant of several drug-drug interactions (DDIs). 2. Effects of the antimalarial agent artemisinin and its structural analogues, artemether, artesunate and dihydroartemisinin, on seven of the major human liver CYP isoforms (CYP1A2, 2A6, 2B6, 2C9, 2C19, 2D6 and 3A4) were evaluated using recombinant enzymes (fluorometric assay) and human liver microsomes (LC-MS/MS analysis). Inhibitory potency (IC50) and mechanisms of inhibition were evaluated using nonlinear regression analysis. In vitro-in vivo extrapolation using the [I]/Ki ratio was applied to predict the risk of DDI in vivo. 3. All compounds tested inhibited the enzymatic activity of CYPs, mostly through a mixed type of inhibition, with CYP1A2, 2B6, 2C19 and 3A4 being affected. A high risk of interaction in vivo was predicted if artemisinin is coadministrated with CYP1A2 or 2C19 substrates. 4. With respect to CYP1A2 inhibition in vivo by artemisinin compounds, our findings are in line with previously published data. However, reported risks of interaction may be overpredicted and should be interpreted with caution.

CYP2D6 is responsible for the oxidative metabolism of 20-25 % of clinical drugs and its genetic polymorphisms can significantly influence the drug metabolism. In this study, we analyzed the functional activities of four nonsynonymous single nucleotide polymorphisms from CYP2D652 allele, which were recently found, and one found frequently in CYP2D6 alleles. Recombinant variant enzymes of E418K, S486T, and R296C were successfully expressed in Escherichia coli and purified. However, a CYP holoenzyme spectrum of P34S variant was not detected in E. coli whole cell level. Structural analysis indicated that P34S mutation seemed to perturb a highly conserved proline-rich N-terminus of CYP2D6. Steady state kinetic analyses showed the significant reductions of enzymatic activities in E418K and R296C variants. In the case of bufuralol 1'-hydroxylation, a novel mutant, E418K, showed 32 % decrease in catalytic efficiency (k cat/K m) mainly due to the decrease of k cat value. R296C showed much greater reduction in the catalytic efficiency (9 % of wild-type) due to both of a decrease of k cat value and an increase of K m value. In the case of dextromethorphan O-demethylation, E418K showed both of a decrease of k cat value and an increase K m value to result in ～43 % reduction of catalytic efficiency. A highly decreased catalytic efficiency (～6 % of wild-type) in the mutant of R296C also was observed mainly due to the dramatic change of k cat value of dextromethorphan O-demethylation. These results suggested that individuals carrying these allelic variants are likely to have the altered metabolic abilities of many clinical drugs therefore, these polymorphisms of CYP2D6 should be much concerned for reliable drug treatment.

The synthesis of hydroxylated and O- or N-dealkylated human drug metabolites (HDMs) via selective monooxygenation remains a challenging task for synthetic organic chemists. Here we report that aromatic peroxygenases (APOs; EC 1.11.2.1) secreted by the agaric fungi Agrocybe aegerita and Coprinellus radians catalyzed the H2O2-dependent selective monooxygenation of diverse drugs, including acetanilide, dextrorphan, ibuprofen, naproxen, phenacetin, sildenafil and tolbutamide. Reactions included the hydroxylation of aromatic rings and aliphatic side chains, as well as O- and N-dealkylations and exhibited different regioselectivities depending on the particular APO used. At best, desired HDMs were obtained in yields greater than 80% and with isomeric purities up to 99%. Oxidations of tolbutamide, acetanilide and carbamazepine in the presence of H218O2 resulted in almost complete incorporation of 18O into the corresponding products, thus establishing that these reactions are peroxygenations. The deethylation of phenacetin-d1 showed an observed intramolecular deuterium isotope effect [(kH/kD) obs] of 3.1 ± 0.2, which is consistent with the existence of a cytochrome P450-like intermediate in the reaction cycle of APOs. Our results indicate that fungal peroxygenases may be useful biocatalytic tools to prepare pharmacologically relevant drug metabolites.

Retrorsine (RTS) and monocrotaline (MCT) cause severe toxicities via P450-mediated metabolic activation. The screening of mechanism-based inhibitors showed RTS inactivated 3A4 in the presence of NADPH. Unlike RTS, MCT failed to inhibit P450 3A4 and other enzymes tested. Further studies showed the loss of P450 3A4 activity occurred in a time- and concentration-dependent way, which was not recovered after dialysis. Dextromethorphan, a P450 3A4 substrate, protected the enzyme from the inactivation. Exogenous nucleophile glutathione (GSH) and reactive oxygen species scavengers catalase and superoxide dismutase did not protect P450 3A4 from the inactivation. GSH trapping experiments showed both P450 3A4 and 2C19 converted RTS and MCT to the corresponding electrophilic metabolites which could be trapped by GSH to form 7-GSH-DHP conjugate. We conclude that RTS and MCT are metabolically activated by P450 3A4 and 2C19, and that RTS, but not MCT, is a mechanism-based inactivator of P450 3A4.

Members of the CYP2D family constitute only about 2-4% of total hepatic CYP450s, however, they are responsible for the metabolism of 20-25% of commonly prescribed therapeutic compounds. CYP2D enzymes have been identified in a number of different species. However, vast differences in the metabolic activity of these enzymes have been well documented. In the horse, the presence of a member of the CYP2D family has been suggested from studies with equine liver microsomes, however its presence has not been definitively proven. In this study a cDNA encoding a novel CYP2D enzyme (CYP2D50) was cloned from equine liver and expressed in a baculovirus expression system. The nucleotide sequence of CYP2D50 was highly homologous to that of human CYP2D6 and therefore the activity of the enzyme was characterized using dextromethorphan and debrisoquine, two isoform selective substrates for the human orthologue. CYP2D50 displayed optimal catalytic activity with dextromethorphan using molar ratios of CYP2D50 to NADPH CYP450 reductase of 1:15. Although CYP2D50 and CYP2D6 shared significant sequence homology, there were striking differences in the catalytic activity between the two enzymes. CYP2D50 dextromethorphan-O-demethylase activity was nearly 180-fold slower than the human counterpart, CYP2D6. Similarly, rates of formation of 4-hydroxydebrisoquine activity were 50-fold slower for CYP2D50 compared to CYP2D6. The results of this study demonstrate substantial interspecies variability in metabolism of substrates by CYP2D orthologues in the horse and human and support the need to fully characterize this enzyme system in equids.

Pharmaceutical compositions and methods for treating neurological disorders by administering same are provided. The compositions comprise dextromethorphan analogs.

Prodrugs of parent drugs and methods of making and using the same are described. The prodrugs comprise an amine-containing parent drug moiety and a prodrug moiety, such as methoxyphosphonic acid or ethoxyphosphonic acid. The prodrugs may be employed in therapy for the treatment of various indications, such as pain, and in methods of decreasing the abuse potential of abuse-prone drugs and/or delaying the onset of parent drug activity and/or prolonging parent drug activity as compared to administration of a parent drug.

The present invention relates to novel crystalline polymorphic forms of levorphanol including hydrated, solvated, and non-hydrated (non-solvated) forms. The invention also describes methods of preparing the various polymorphic forms. The present invention also relates to pharmaceutical compositions containing crystalline polymorphs of levorphanol, as well as methods of relieving pain by administering the pharmaceutical compositions.

The present invention provides novel methods for monitoring subject adherence in taking prescribed drugs by detecting markers in exhaled breath after a subject takes the prescribed drug. In particular, the present invention provides novel methods for making additives that are combined with the drug(s). Upon biological breakdown of the drug/additive formulation in a subject's body, markers resulting directly from the biological breakdown of the additives are detected in exhaled breath using sensor technology. In certain embodiments of the invention, the drug adherence monitoring systems and methods include a reporting system capable of tracking subject compliance (either remotely or proximately) and of providing necessary alerts to the subject, caregiver, healthcare provider, and the like.

A process for the production of morphinans with higher purity and yield, when compared to the conventional process, is described. Specifically, the process may be used to prepare levorphanol, levorphanol tartrate, and levorphanol tartrate dihydrate in high yields and substantially free from several process impurities.

Active compound combinations of compounds of group A, particularly opioids, and compounds of group B, particularly anti-muscarine agents and other substances suitable for treatment of an increased urge to urinate or urinary incontinence. Related pharmaceutical formulations and methods of treatment of an increased urge to urinate or urinary incontinence are also provided.

Objective: Knowledge about the metabolism of anti-parasitic drugs (APDs) will be helpful in ongoing efforts to optimise dosage recommendations in clinical practise. This study was performed to further identify the cytochrome P450 (CYP) enzymes that metabolise major APDs and evaluate the possibility of predicting in vivo drug clearances from in vitro data. Methods: In vitro systems, rat and human liver microsomes (RLM, HLM) and recombinant cytochrome P450 (rCYP), were used to determine the intrinsic clearance (CLint) and identify responsible CYPs and their relative contribution in the metabolism of 15 commonly used APDs. Results and discussion: CLint determined in RLM and HLM showed low (r2=0.50) but significant (Pint values were scaled to predict in vivo hepatic clearance (CLH) using the 'venous equilibrium model'. The number of compounds with in vivo human CL data after intravenous administration was low (n=8), and the range of CL values covered by these compounds was not appropriate for a reasonable quantitative in vitro-in vivo correlation analysis. Using the CLH predicted from the in vitro data, the compounds could be classified into three different categories: high-clearance drugs (> 70% liver blood flow; amodiaquine, praziquantel, albendazole, thiabendazole), low-clearance drugs (int drug categories. The identified CYPs for some of the drugs provide a basis for how these drugs are expected to behave pharmacokinetically and help in predicting drug-drug interactions in vivo.

In this study, the basis for the diminished capacity of CYP2D6.17 to metabolise CYP2D6 substrate drugs and the possible implications this might have for CYP2D6 phenotyping studies and clinical use of substrate drugs were investigated in vitro. Enzyme kinetic analyses were performed with recombinant CYP2D6.1, CYP2D6.2, CYP2D6.17 and CYP2D6.T107I using bufuralol, debrisoquine, metoprolol and dextromethorphan as substrates. In addition, the intrinsic clearance of 10 CYP2D6 substrate drugs by CYP2D6.1 and CYP2D6.17 was determined by monitoring substrate disappearance. CYP2D6.17 exhibited generally higher Km values compared to CYP2D6.1. The Vmax values were generally not different except for metoprolol α-hydroxylation with the Vmax value for CYP2D6.17 being half that of CYP2D6.1. CYP2D6.1 and CYP2D6.2 displayed similar kinetics with all probe drugs except for dextromethorphan O-demethylation with the intrinsic clearance value of CYP2D6.2 being half that of CYP2D6.1. CYP2D6.17 exhibited substrate-dependent reduced clearances for the 10 substrates studied. In a clinical setting, the clearance of some drugs could be affected more than others in individuals with the CYP2D6* 17 variant. The CYP2D6* 17 allele might, therefore, contribute towards the poor correlation of phenotyping results when using different probe drugs in African populations. To investigate effects of CYP2D6* 17 mutations on the structure of the enzyme, a homology model of CYP2D6 was built using the CYP2C5 crystal structure as a template. The results suggest an alteration in position of active-site residues in CYP2D6.17 as a possible explanation for the reduced activity of the enzyme.

We recently reported on the design, synthesis and characterisation of a novel and selective substrate of human cytochrome P450 2D6 (CYP2D6), 7-methoxy-4-(aminomethyl)-coumarin (MAMC). Here, we describe a high-throughput microplate reader assay, which makes use of MAMC as a fluorescent probe for determining the inhibition and activity of CYP2D6 in heterologously expressed systems and human liver microsomes. The high-throughput screening (HTS) assay can be used both in an end-point and real-time configuration, and is easy to use, rapid and sensitive. In addition, end-point measurements by means of flow injection analysis have also successfully been performed. The HTS-assay was validated by performing inhibition experiments for several low- and high-affinity ligands (n=6) of CYP2D6, and comparing the findings to those obtained with the standard O-demethylation assay of dextromethorphan. The results indicate that all compounds tested display competitive inhibition in both the MAMC and dextromethorphan assay, and the K(i) values reveal a very good correlation (R2=0.984) between the two assays. To further demonstrate the usefulness of the HTS-assay, IC50 values of a series of five N-substituted analogs of 3,4-methylenedioxyamphetamine for CYP2D6 have been determined. The results obtained demonstrate that the current HTS-assay represents a significant improvement over previous assays, with a higher turnover of MAMC and a higher selectivity for CYP2D6. Copyright (C) 2000 Elsevier Science B.V.

Preparation of destrorphan citrate, a very soluble salt in water, in described. This salt may be used in oral composition with anti-tussive activity. Structural date are reported about 1H-NMR, 13C-NMR, COSY.

Dextromethorphan (1, (+)-3-methoxy-17-methylmorphinan) demonstrates anticonvulsant activity in a variety of in vitro and in vivo models of convulsive action.It is well known that 1 is metabolized to its phenolic derivative dextrorphan (2) and this metabolite is also a potent anticonvulsant.A series of (+)-3-substituted-17-methylmorphinans, which are structurally similar to 1 but are either not expected to be metabolized to 2 or might do so at a reduced rate, as compared to 1, were prepared.Three analogs, 5 ((+)-3-amino-17-methylmorphinan), 14 ((+)-3-ethoxy-17-methylmorphinan), and 15 ((+)-3-(2-propoxy)-17-methylmorphinan were found to possess potent anticonvulsant activity with full efficacy (ED50 25, 5.6, and 3.9 mg/kg, sc, respectively) in the rat supramaximal electroshock (MES) test.Binding potencies of these compounds to receptor sites labeled with 3H>dextromethorphan (3H>1), in rat brain and guinea pig brain subcellular fractions, and 3H>thienylcyclohexylpiperidine (TCP) and 3H>glycine in rat brain, were determined.Most of the analogs displaced 3H>1 from its binding sites, with compounds 14 (IC50 0.42 μM) and 15 (IC50 0.88 μM having equivalent potencies to 1 (IC50 0.59 μM), in rat brain, and no appreciable activity at the 3H>TCP or 3H>glycine-labeled sites.Compound 5 did not bind with appreciable activity to the 3H>1 site, in rat brain, but did bind to the 3H>TCP site with lower potency than the parent 1 (IC50 7.8 and 2.0 μM, respectively).The mechanism of anticonvulsant action of these agents is not clear although it appears that interaction at the 3H>1 sites may be involved.

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