Search of anti-allodynic compounds from Plantaginis Semen,a crude drug ingredient of Kampo formula “Goshajinkigan”

Journal of Natural Medicines - Chemotherapy-induced peripheral neuropathy (CIPN) is one of the dose-limiting side effects of cancer chemotherapy. Although the control of CIPN is important, it is...     

Identification and differentiation of major components in three different “Sheng-ma” crude drug species by UPLC/Q-TOF-MS

Cimicifugae Rhizoma (Sheng ma) is a Ranunculaceae herb belonging to a composite family and well known in China. has been widely used in traditional Chinese medicine. The Pharmacopoeia of the People׳s Republic of China contains three varieties (Cimicifuga dahurica (Turcz.), Cimicifuga foetida L. and Cimicifuga heracleifolia Kom.) which have been used clinically as “Sheng-ma”. However, the chemical constituents of three components of “Sheng-ma” have never been documented. In this study, a rapid method for the analysis of the main components of “Sheng-ma” was developed using ultra-high performance liquid chromatography with quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS). The present study reveals the major common and distinct chemical constituents of C. dahurica, C. foetida and C. heracleifolia and also reports principal component and statistical analyses of these results. The components were identified by comparing the retention time, accurate mass, mass spectrometric fragmentation characteristic ions and matching empirical molecular formula with that of the published compounds. A total of 32 common components and 8 markers for different “Sheng-ma” components were identified. These findings provide an important basis for the further study and clinical utilities of the three “Sheng-ma” varieties.     

Edoxaban drug–drug interactions with ketoconazole,erythromycin, and cyclosporine

AimsEdoxaban, a novel factor Xa inhibitor, is a substrate of cytochrome P450 3 A4 (CYP3A4) and the efflux transporter P‐glycoprotein (P‐gp). Three edoxaban drug–drug interaction studies examined the effects of P‐gp inhibitors with varying degrees of CYP3A4 inhibition.MethodsIn each study, healthy subjects received a single oral dose of 60 mg edoxaban with or without an oral dual P‐gp/CYP3A4 inhibitor as follows: ketoconazole 400 mg once daily for 7 days, edoxaban on day 4; erythromycin 500 mg four times daily for 8 days, edoxaban on day 7; or single dose of cyclosporine 500 mg with edoxaban. Serial plasma samples were obtained for pharmacokinetics and pharmacodynamics. Safety was assessed throughout the study.ResultsCoadministration of ketoconazole, erythromycin, or cyclosporine increased edoxaban total exposure by 87%, 85%, and 73%, respectively, and the peak concentration by 89%, 68%, and 74%, respectively, compared with edoxaban alone. The half‐life did not change appreciably. Exposure of M4, the major active edoxaban metabolite, was consistent when edoxaban was administered alone or with ketoconazole and erythromycin. With cyclosporine, M4 total exposure increased by 6.9‐fold and peak exposure by 8.7‐fold, suggesting an additional interaction. Pharmacodynamic effects were reflective of increased edoxaban exposure. No clinically significant adverse events were observed.ConclusionsAdministration of dual inhibitors of P‐gp and CYP3A4 increased edoxaban exposure by less than two‐fold. This effect appears to be primarily due to inhibition of P‐gp. The impact of CYP3A4 inhibition appears to be less pronounced, and its contribution to total clearance appears limited in healthy subjects.     

The “iatrogenic triad”: polypharmacy,drug–drug interactions,and potentially inappropriate medications in older adults

International Journal of Clinical Pharmacy - Background The elderly population is often in continuous use of several medications and is more subject to the “iatrogenic triad” of...     

Correction to: Search of anti-allodynic compounds from Plantaginis Semen,a crude drug ingredient of Kampo formula “Goshajinkigan”

Journal of Natural Medicines - The article Search of anti-allodynic compounds from Plantaginis Semen, a crude drug ingredient of Kampo formula “Goshajinkigan”.     

Bio-relevant media to assess drug permeability: sodium taurocholate and lecithin combination or crude bile?

The assessment of in vivo drug absorption with in vitro permeability models demands the use of transport media with surface acting compounds. With the aim to establish their influence on in vitro permeability of 30 drugs through Caco-2 monolayers, cell vitality/integrity and micellar drug entrapment, taurocholate/lecithin (NaTC/Leci) and pig crude bile were applied. Drug permeabilities were correlated to fraction of drugs absorbed and appropriate NaTC/Leci and bile concentrations were proposed to simulate fasted/fed conditions in vitro (bile in the concentration range 1-5 v/v% or 0.2/0.05mM NaTC/Leci for fasted; 10 v/v% bile or 3/0.75mM NaTC/Leci for fed conditions) without detrimental effects on monolayer integrity/vitality (NaTC/Leci was more toxic than bile). Surfactants exerted different affinities for drugs; free drug concentration (c(free)) of some was significantly lowered only by bile, while for the others NaTC/Leci and bile significantly diminished c(free). For some substances NaTC/Leci and bile significantly increased their permeabilities (i.e. more than 3-times) in spite of profound c(free) decrease indicating the existence of an alternative absorption mechanism. Based on these data, the impact of bile on in vitro drug permeability and micellar drug entrapment cannot be adequately simulated by NaTC/Leci, because their effects on drug absorption differ.     

Can formulation and drug delivery reduce attrition during drug discovery and development—review of feasibility,benefits and challenges

Drug discovery and development has become longer and costlier process. The fear of failure and stringent regulatory review process is driving pharmaceutical companies towards “me too” drugs and improved generics (505(b) (2)) fillings. The discontinuance of molecules at late stage clinical trials is common these years. The molecules are withdrawn at various stages of discovery and development process for reasons such as poor ADME properties, lack of efficacy and safety reasons. Hence this review focuses on possible applications of formulation and drug delivery to salvage molecules and improve the drugability. The formulation and drug delivery technologies are suitable for addressing various issues contributing to attrition are discussed in detail.KEY WORDS: Drug discovery and development, Drugability, Formulation, Drug delivery technology     

Clinical disposition,metabolism and in vitro drug–drug interaction properties of omadacycline

1.?Absorption, distribution, metabolism, transport and elimination properties of omadacycline, an aminomethylcycline antibiotic, were investigated in vitro and in a study in healthy male subjects.

2.?Omadacycline was metabolically stable in human liver microsomes and hepatocytes and did not inhibit or induce any of the nine cytochrome P450 or five transporters tested. Omadacycline was a substrate of P-glycoprotein, but not of the other transporters.

3.?Omadacycline metabolic stability was confirmed in six healthy male subjects who received a single 300?mg oral dose of [¹⁴C]-omadacycline (36.6 μCi). Absorption was rapid with peak radioactivity (～610 ngEq/mL) between 1–4?h in plasma or blood. The AUC_last of plasma radioactivity (only quantifiable to 8?h due to low radioactivity) was 3096 ngEq?h/mL and apparent terminal half-life was 11.1?h. Unchanged omadacycline reached peak plasma concentrations (～563?ng/mL) between 1–4?h. Apparent plasma half-life was 17.6?h with biphasic elimination. Plasma exposure (AUC_inf) averaged 9418?ng?h/mL, with high clearance (CL/F, 32.8?L/h) and volume of distribution (Vz/F 828?L). No plasma metabolites were observed.

4.?Radioactivity recovery of the administered dose in excreta was complete (>95%); renal and fecal elimination were 14.4% and 81.1%, respectively. No metabolites were observed in urine or feces, only the omadacycline C4-epimer.     

Non-alcoholic fatty liver disease (NAFLD) – pathogenesis,classification, and effect on drug metabolizing enzymes and transporters

Non-alcoholic fatty liver disease (NAFLD) is a spectrum of liver disorders. It is defined by the presence of steatosis in more than 5% of hepatocytes with little or no alcohol consumption. Insulin resistance, the metabolic syndrome or type 2 diabetes and genetic variants of PNPLA3 or TM6SF2 seem to play a role in the pathogenesis of NAFLD. The pathological progression of NAFLD follows tentatively a “three-hit” process namely steatosis, lipotoxicity and inflammation. The presence of steatosis, oxidative stress and inflammatory mediators like TNF-α and IL-6 has been implicated in the alterations of nuclear factors such as CAR, PXR, PPAR-α in NAFLD. These factors may result in altered expression and activity of drug metabolizing enzymes (DMEs) or transporters.

Existing evidence suggests that the effect of NAFLD on CYP3A4, CYP2E1 and MRP3 is more consistent across rodent and human studies. CYP3A4 activity is down-regulated in NASH whereas the activity of CYP2E1 and the efflux transporter MRP3 is up-regulated. However, it is not clear how the majority of CYPs, UGTs, SULTs and transporters are influenced by NAFLD either in vivo or in vitro. The alterations associated with NAFLD could be a potential source of drug variability in patients and could have serious implications for the safety and efficacy of xenobiotics. In this review, we summarize the effects of NAFLD on the regulation, expression and activity of major DMEs and transporters. We also discuss the potential mechanisms underlying these alterations.     

Has molecular and cellular imaging enhanced drug discovery and drug development?

A great many efforts have been made to accelerate the drug discovery and development process, which is extremely time and money consuming. Recently developed molecular imaging has many significant advantages over conventional methods for examining molecular pathways and obtaining pharmacokinetic, pharmacodynamic and mechanistic information. This review briefly summarizes various molecular and cellular imaging techniques and discusses several important applications of molecular and cellular imaging in drug discovery and development, which include: (i) measurement of pharmacodynamic endpoints by imaging metabolism and proliferation, imaging angiogenic parameters, and imaging a particular pathway or downstream target; (ii) evaluation of pharmacokinetics; and (iii) imaging therapeutic gene expression with relevance to gene therapy. Molecular imaging is becoming more widely used as a non-invasive tool for drug discovery and drug screening. Further refinements in imaging techniques, optimization of imaging probes and collaborative efforts will be needed to fully realise the vast potential of molecular imaging techniques in discovering and developing new drugs.     

Biotransformation and in vitro assessment of metabolism-associated drug–drug interaction for CRx-102, a novel combination drug candidate

CRx-102 is an oral synergistic combination drug which contains the cardiovascular agent, dipyridamole (DP) and a very low dose of the glucocorticoid, prednisolone (PRED). CRx-102 works through a novel mechanism of action in which DP selectively amplifies the anti-inflammatory activity of PRED without replicating its side effects. CRx-102 is in clinical trials for the treatment of osteoarthritis. Here we delineate the in vitro metabolism and explore the potential for a drug–drug interaction between the active agents in CRx-102. Our study using human hepatocyte suspensions showed that both DP and PRED were metabolized by CYP3A4 isozymes, resulting in the formation of diverse arrays of both oxidative and oxidative-reduced metabolites. Within phase 1 biotransformation, CYP3A4 was one of the pathways responsible for the metabolism of PRED, while phase 2 biotransformation played a significant role in the metabolism of DP. Glucuronidation of DP was substantial and was catalyzed by many UGT members, specifically those in the UGT1A subfamily. Based on the tandem mass (MS/MS) product ion spectra (PIS) acquired, the major metabolites of both agents, namely, monooxygenated, mono-N-deethanolaminated, dehydrogenated and O-glucuronidated metabolites of DP and the monooxygenated (e.g., 6-hydroxyl), dehydrogenated (prednisone) and reduced (20-hydroxyl) metabolites of PRED, were identified and elucidated. The affinities for DP biotransformation, including CYP3A4-mediated oxidative pathways and UGT-mediated O-glucuronidation, appeared high (K_m < 10 μM), as compared with the modest affinities of PRED biotransformation catalyzed by CYP3A4 (K_m ∼ 40–170 μM). DP, but not PRED, exerted a minimal inhibitory effect on the drug-metabolizing CYP isoforms, including CYP3A4, which was determined using a panel of CYP isoform-preferred substrate activities in pooled human liver microsomal (HLM) preparations and microsomal preparations containing the recombinant enzymes (K_i ∼ 2–12 μM). Using the DP maximal plasma concentration (C_max) observed in the clinic and a predictive mathematical model for metabolism-associated drug–drug interaction (DDI), we have demonstrated that there is little likelihood of a pharmacokinetic interaction between the two active agents in CRx-102.     

Epidemiology and characteristics of adverse drug reactions caused by drug–drug interactions

Introduction: Drug–drug interactions (DDIs) arise in numerous different ways, involving pharmacokinetic or pharmacodynamic mechanisms. Adverse drug reactions are a possible consequence of DDIs and health operators are often unaware of the clinical risks of certain drug combinations. Many papers on drug interactions have been published in recent years, but most of them focused on potential DDIs while few studies have been conducted on actual interactions.

Areas covered: This paper reviews the epidemiology of actual DDIs in outpatients as well as in hospital settings and in spontaneous reporting databases. The incidence of actual DDIs is consistently lower than that of potential DDIs. However, the absolute number of patients involved is high, representing a significant proportion of adverse drug reactions. The importance of risk factors such as age, polypharmacy and genetic polymorphisms is also evaluated. The relevance and efficacy of tools for recognizing and preventing DDIs are discussed.

Expert opinion: Potential DDIs far outnumber actual drug interactions. The potential for an adverse interaction to occur is often theoretical, and clinically important adverse effects occur only in the presence of specific risk factors. Several studies have shown the efficacy of computers in early detection of DDIs. However, a correct risk–benefit evaluation by the prescribing physician, together with a careful clinical, physiological and biochemical monitoring of patients, is essential. Future directions of drug interaction research include the increasing importance of pharmacogenetics in preventing DDIs and the evaluation of interactions with biological drugs.     

Population pharmacokinetic analysis of drug–drug interactions among risperidone,bupropion, and sertraline in CF1 mice

Rationale Accumulating evidence indicates that modulation of the activity of cytochrome P450 (CYP) enzymes and the multidrug resistance transporter P-glycoprotein (P-gp) is responsible for many drug–drug interactions. Objectives The potential interaction of risperidone (RISP), which is metabolized by 2D6 and transported across the blood brain barrier (BBB) by P-gp, was studied in combination with bupropion (BUP) and also with sertraline (SERT). Methods BUP, SERT, and RISP were administered intraperitoneally into CF1 mice at doses of 100, 10, and 1 μg/g mouse, respectively. Plasma and brain samples were collected at timed intervals from 0.5 to 6 h. A pharmacokinetic analysis was performed using both traditional compartmental modeling and a population pharmacokinetic approach. Results BUP increased the RISP plasma (5.9-fold, P<0.01) and brain (2.2-fold, P<0.01) area under the drug concentration vs time curve (AUC), but did not alter the brain-to-plasma concentration ratio. SERT did not significantly change the plasma AUC of RISP and 9-hydroxy-RISP, but increased the brain AUC of RISP and 9-hydroxy-RISP 1.5-fold (P<0.05) and 5-fold (P<0.01), respectively. RISP did not produce significant alterations of plasma or brain concentrations of BUP. It increased the plasma AUC and elimination half-life (T _1/2e) of desmethyl-SERT 12.5-fold (P<0.01) and 107-fold (P<0.01), respectively. Conclusions These results suggest that pharmacokinetic interactions exist among these three psychoactive drugs involving inhibition of drug metabolizing enzymes and/or P-gp and other drug transporters present in the BBB. The mechanisms and consequences of these interactions require further study in humans to establish clinical relevance.     

Biomarkers,metabonomics, and drug development: Can inborn errors of metabolism help in understanding drug toxicity?

Application of "omics" technology during drug discovery and development is rapidly evolving. This review evaluates the current status and future role of "metabonomics" as a tool in the drug development process to reduce the safety-related attrition rates and bridge the gaps between preclinical and clinical, and clinical and market. Particularly, the review looks at the knowledge gap between the pharmaceutical industry and pediatric hospitals, where metabonomics has been successfully applied to screen and treat newborn babies with inborn errors of metabolism. An attempt has been made to relate the clinical pathology associated with inborn errors of metabolism with those of drug-induced pathology. It is proposed that extending the metabonomic biomarkers used in pediatric hospitals, as "advanced clinical chemistry" for preclinical and clinical drug development, is immediately warranted for better safety assessment of drug candidates. The latest advances in mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy should help replace the traditional approaches of laboratory clinical chemistry and move the safety evaluation of drug candidates into the new millennium.     

Constituents of the chinese crude drug "Sāng-Bái-Pí" (morus root bark)

From the benzene extract of the Chinese crude drug "Sāng-Bái-Pí" (Japanese name Sōhakuhi), the root barks of MORUS sp. (Moraceae), a novel isoprene substituted flavanone derivative, named sanggenon B, was isolated; its structure was shown to be I on the basis of spectral and chemical data. Sanggenon B (I) is regarded biogenetically as a variation of a Diels-Alder adduct of a chalcone derivative and a dehydroprenylflavanone derivative.     

Constituents of the Chinese crude drug "sāng-bái-pí" (Morus root bark)

From the benzene extract of the Chinese crude drug "Sāng-Bái-Pí" (Japanese name Sōhakuhi), the root bark of MORUS sp. (Moraceae), a novel isoprene substituted flavanone, named sanggenon A, was isolated whose structure was shown to be I on the basis of spectral data. A known isoprene substituted flavone derivative, morusin (II), was also obtained from the extract.