Publications by authors named "Chongwoo Yu"

The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) adopted Guideline M10 entitled "Bioanalytical Method Validation and Study Sample Analysis" in May 2022. In October 2023, approximately one year after the adoption of the ICH M10 guideline, a "Hot Topic" session was held during the AAPS PharmSci 360 meeting to discuss the implementation of the guideline. The session focused on items the bioanalytical community felt were challenging to implement or ambiguous within the guideline.

View Article and Find Full Text PDF

Endogenous therapeutic analytes include hormones, neurotransmitters, vitamins, fatty acids and inorganic elements that are naturally present in the body because either the body produces them or they are present in the normal diet. The accurate measurement of endogenous therapeutic analytes poses a challenge when the administered exogenous therapeutic analyte and its endogenous counterpart cannot be distinguished. In this article, real case examples with endogenous therapeutic analyte bioanalysis during drug development in support of regulatory submissions are collected and presented.

View Article and Find Full Text PDF

Potential drug interactions with hormonal contraceptives are an important public health concern. A public meeting on "Drug Interactions With Hormonal Contraceptives: Public Health and Drug Development Implication" was hosted by the United States Food and Drug Administration (FDA). The meeting endeavored to provide an opportunity for the FDA to seek input from experts on the public health concerns associated with the use of hormonal contraceptives and interacting drugs that might affect efficacy and safety, including pharmacokinetic/pharmacodynamic considerations, in the design of drug interaction studies of hormonal contraceptives for drug development and approaches to translating the results of drug interaction information into informative labeling and communication.

View Article and Find Full Text PDF

Objective: The objective of this investigation was to assess the potential effect of obesity on the effectiveness of hormonal contraceptives (HCs).

Study Design: A meta-analysis was conducted using individual participant data directly from the Phase 3 clinical trials of combination oral contraceptives (COCs) rather than extracting summary data from literature. Trials selected were reviewed by the US Food and Drug Administration (FDA) between 2000 and 2012, conducted in North America, had more than six 28-day cycle equivalents of exposure, and had readily retrievable participant-level data.

View Article and Find Full Text PDF

Clinical pharmacology plays an important role in drug development, including the evaluation of the drug's pharmacokinetics, pharmacodynamics, drug-interaction potential, exposure-response relationship and safety considerations when being used in specific populations. Clinical pharmacology data is pivotal in ensuring the delivery of the right drug, in the right dose, at the right time, to each particular patient and it has significantly influenced the risk/benefit assessment and labeling recommendations. Consequently, the reliability of the bioanalytical methods and data are of considerable importance, and the solid footing in drug development.

View Article and Find Full Text PDF

The electronic common technical document (eCTD) format is frequently used in submitting bioanalytical information as part of a new drug application (NDA) or biologics license application (BLA). While the use of the eCTD format has many advantages, the potential for further improvement exists. This review highlights issues that are commonly encountered in reviewing bioanalytical information during the review process.

View Article and Find Full Text PDF

Gemfibrozil coadministration generally results in plasma statin area under the curve (AUC) increases, ranging from moderate (2- to 3-fold) with simvastatin, lovastatin, and pravastatin to most significant with cerivastatin (5.6-fold). Inhibition of statin glucuronidation has been postulated as a potential mechanism of interaction (Drug Metab Dispos 30:1280-1287, 2002).

View Article and Find Full Text PDF

Objectives: Our objectives were to evaluate the contribution of bergamottin to the grapefruit juice-felodipine interaction and to characterize bergamottin disposition.

Methods: In this study 250 mL grapefruit juice; 2-, 6-, or 12-mg capsules of bergamottin plus water; or water was administered with 5 mg extended-release felodipine to 11 volunteers in a partially randomized, 5-way crossover study. Plasma concentrations of felodipine, its primary metabolite (dehydrofelodipine), bergamottin, and 6',7'-dihydroxybergamottin were determined.

View Article and Find Full Text PDF

Compound extraction from biological tissue often presents a challenge for the bioanalytical chemist. Labor-intensive homogenization or sonication of whole or powdered tissue is performed before compounds can be extracted and analyzed. Enzymatic digestion is commonly used for tissue dissociation and cell harvesting and offers the advantages of unattended sample preparation, potential automation, and low cost.

View Article and Find Full Text PDF

The Caco-2 cell monolayer permeability assay has become a standard model of human intestinal absorption and transport. This paper reviews recent progress in increasing the throughput of Caco-2 cell monolayer assays and in expanding the scope of this assay to include modeling intestinal drug metabolism. The state-of-the-art in Caco-2 cell monolayer permeability assays combines multi-well plates fitted with semi-permeable inserts on which Caco-2 cells have been cultured with liquid chromatography-mass spectrometry (LC-MS) or LC-tandem mass spectrometry (LC-MS-MS) for the quantitative analysis of test compounds and the identification of their intestinal metabolites.

View Article and Find Full Text PDF

Resveratrol in the fruits of bilberry (Vaccinium myrtillus L.), the lowbush "wild" blueberry (Vaccinium angustifolium Aiton), the rabbiteye blueberry (Vaccinium ashei Reade), and the highbush blueberry (Vaccinium corymbosum L.) were measured using a new assay based on high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS).

View Article and Find Full Text PDF

trans-Resveratrol, a phenolic phytoalexin occurring in grapes, wine, peanuts, and cranberries, has been reported to both have anticarcinogenic, antioxidative, phytoestrogenic, and cardioprotective activities, and to be a weak inhibitor of cytochrome P450 (CYP)3A4, which might have significance for drug-drug interactions. Since trans-resveratrol is rapidly converted in vivo to primarily trans-resveratrol-3-sulfate, a rapid, selective, and sensitive method using liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed to investigate human cytochrome P450 inhibition by trans-resveratrol-3-sulfate. Effects of trans-resveratrol and trans-resveratrol-3-sulfate on the metabolism of selective cytochrome P450 substrates (CYP1A2/ethoxyresorufin, CYP2C9/diclofenac, CYP2C19/(S)-mephenytoin, CYP2D6/bufuralol, CYP3A4/testosterone) were monitored using cDNA-expressed human recombinant isozymes.

View Article and Find Full Text PDF

Purpose: Resveratrol, a phenolic phytoalexin occurring in grapes, wine, peanuts, and cranberries, has been reported to have anticarcinogenic, antioxidative, phytoestrogenic, and cardioprotective activities. Because little is known about the metabolism of this potentially important compound, the in vitro and in vivo metabolism of trans-resveratrol were investigated.

Methods: The in vitro experiments included incubation with human liver microsomes, human hepatocytes, and rat hepatocytes and the in vivo studies included oral or intraperitoneal administration of resveratrol to rats and mice.

View Article and Find Full Text PDF