Validated LC–MS/MS method for the determination of some prescribed CNS drugs: Application to an in vivo pharmacokinetic study of drug-herb metabolic interaction potential of khat

Bioanalytical LC-MS/MS method for simultaneous estimation of atorvastatin, its major active metabolites and ezetimibe

Background: Hyperlipidemia is one of the most common chronic diseases encountered globally, and atorvastatin (ATV) is mainly metabolized into two major active metabolites. Methodology: Hence, we aimed to estimate ATV and ezetimibe (EZE) simultaneously in the presence of ATV major and active metabolites using a validated LC-MS/MS method. Conclusion: The proposed method was linear (r² >0.99), accurate (92.02-109.94%) and precise (CV% ≤14) over the concentration range of 0.50-120 ng/ml, 0.20-48 ng/ml, 0.50-120 ng/ml and 0.20-48 ng/ml for ATV, EZE, 2-hydroxy ATV and 4-hydroxy ATV, respectively. The applied liquid-liquid extraction gave rise to reliable extraction recoveries of 84.91 ± 1.14%, 85.20 ± 1.62%, 85.46 ± 0.41% and 105.46 ± 2.35% for ATV, EZE, 2-hydroxy ATV and 4-hydroxy ATV, respectively.

Synthesis, biological evaluation, pharmacokinetic studies and molecular docking of 4'''-acetyl-delicaflavone as antitumor agents

Structural modification of natural products is the effective option to improve their pharmacological effects and drug properties. DLF is a lead compound of antitumor drug, which is a broad-spectrum, low toxic and high-efficient component isolated from Selaginella doederleinii Hieron by our research group. Here, we report the structural modification method of this component, and find that the acetylated product of C4'''- OH (C4'''-acetyl-delicaflavone, 4'''ADLF) has better inhibitory effect on the selected cancer cell lines, including, lung, liver, colon and cervical cancer cell lines. Since the increased water solubility of 4'''ADLF may lead to higher absorption rate and activity, we evaluate the pharmacodynamics in vitro and in vivo, and the pharmacokinetic of 4'''ADLF. It shows that 4'''ADLF inhibit the proliferation and induce cycle arrest in tumor cells, and had better anticancer activity and bioavailability than DLF.

The impact of catha edulis (vahl) forssk. ex endl. (celestraceae) (khat) on pharmacokinetics of clinically used drugs

INTRODUCTION

Catha edulis (Vahl) Forssk. ex Endl. (Celestraceae) is used as a recreational drug on daily basis for its euphoric and psychostimulant effects. It is also chewed by individuals who are on medications, raising the possibility of drug-khat interaction. However, limited data are available in the literature, although clinically significant interactions are expected, as khat contains a complex mixture of pharmacologically active constituents.

AREAS COVERED

It provides an overview of the phytochemistry, pharmacokinetics, pharmacodynamics, and pharmacogenetics of khat based on the literature mined from PubMed, Google Scholar, and Cochrane databases. It also presents a detailed account of drug-khat interactions with specific examples and their clinical significance. The interactions mainly occur at the pharmacokinetics level and particular attention is paid for the phases of absorption and cytochrome P450 enzyme-mediated metabolism.

EXPERT OPINION

Despite the increasing trend of khat chewing with medications among the populace and the potential risk for the occurrence of clinically significant interactions, there is paucity of data in the literature demonstrating the magnitude of the risk. The available data, however, clearly demonstrate that the consequence of drug-khat interaction is dependent on genotype. Genotyping, where feasible, could be used to improve clinical outcome and minimize adverse reactions.

In vitro effects of 95% khat ethanol extract (KEE) on human recombinant cytochrome P450 (CYP)1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2 and CYP3A5

OBJECTIVES

Khat, a natural amphetamine-like psychostimulant plant, are widely consumed globally. Concurrent intake of khat and xenobiotics may lead to herb-drug interactions and adverse drug reactions (ADRs). This study is a continuation of our previous study, targeted to evaluate the in vitro inhibitory effects of khat ethanol extract (KEE) on human cytochrome (CYP) 1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2, and CYP3A5, major human drug metabolizing enzymes.

METHODS

In vitro fluorescence enzyme assays were employed to assess CYPs inhibition with the presence and absence of various KEE concentrations.

RESULTS

KEE reversibly inhibited CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2 and CYP3A5 but not CYP1A2 with IC₅₀ values of 25.5, 99, 4.5, 21, 27, 17, and 10 μg/mL respectively. No irreversible inhibition of KEE on all the eight CYPs were identified. The K_i values of CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2 and CYP3A5 were 20.9, 85, 4.8, 18.3, 59.3, 3, and 21.7 μg/mL, respectively. KEE inhibited CYP2B6 via competitive or mixed inhibition; CYP2E1 via un-competitive or mixed inhibition; while CYP2A6, CYP2C8, CYP2C19, CYP2J2 and CYP3A5 via non-competitive or mixed inhibition.

CONCLUSIONS

Caution should be taken by khat users who are on medications metabolized by CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2, and CYP3A5.

Non-extractive spectrophotometric determination of memantine HCl, clomipramine HCl and fluvoxamine maleate in pure form and in pharmaceutical products by ion-pair complex formation with rose bengal

OBJECTIVES

The objective of this work is to develop a simple, sensitive and non-extractive spectrophotometric method for the determination of memantine HCl (MEM), clomipramine HCl (CLM) and fluvoxamine maleate (FLV).

MATERIAL AND METHODS

The proposed method was based on the formation of colored ion-pair complexes between the basic nitrogen of the target drugs and rose bengal (RB) dye in a weak acidic medium.

RESULTS

The formed complexes were measured at 576nm for MEM, CLM and at 575nm for FLV. The reaction conditions were optimized to obtain the maximum color intensity. Beer's law was obeyed in the range of 2-20, 1-16 and 6-30μg/mL for MEM, CLM and FLV, respectively. The limit of detection (LOD) was 0.476, 0.185, 0.806 and the limit of quantitation (LOQ) was 1.443, 0.559 and 2.443 for MEM, CLM and FLV, respectively. The composition ratio of the ion-pair complexes was found to be 1:1 as determined by Job's method.

CONCLUSION

The proposed method was applied successfully for the analysis of the cited drugs in pure and dosage forms. Results of the proposed method were statistically compared with the reported methods by applying student's t- and F-tests and no significant differences were observed.

Impacts of Drug Interactions on Pharmacokinetics and the Brain Transporters: A Recent Review of Natural Compound-Drug Interactions in Brain Disorders

Natural compounds such as herbal medicines and/or phyto-compounds from foods, have frequently been used to exert synergistic therapeutic effects with anti-brain disorder drugs, supplement the effects of nutrients, and boost the immune system. However, co-administration of natural compounds with the drugs can cause synergistic toxicity or impeditive drug interactions due to changes in pharmacokinetic properties (e.g., absorption, metabolism, and excretion) and various drug transporters, particularly brain transporters. In this review, natural compound–drug interactions (NDIs), which can occur during the treatment of brain disorders, are emphasized from the perspective of pharmacokinetics and cellular transport. In addition, the challenges emanating from NDIs and recent approaches are discussed.