In Vivo Predictive Dissolution and Simulation Workshop Report: Facilitating the Development of Oral Drug Formulation and the Prediction of Oral Bioperformance

Quantification of Fluid Volume and Distribution in the Paediatric Colon via Magnetic Resonance Imaging

Previous studies have used magnetic resonance imaging (MRI) to quantify the fluid in the stomach and small intestine of children, and the stomach, small intestine and colon of adults. This is the first study to quantify fluid volumes and distribution using MRI in the paediatric colon. MRI datasets from 28 fasted (aged 0-15 years) and 18 fluid-fed (aged 10-16 years) paediatric participants were acquired during routine clinical care. A series of 2D- and 3D-based software protocols were used to measure colonic fluid volume and localisation. The paediatric colon contained a mean volume of 22.5 mL ± 41.3 mL fluid, (range 0-167.5 mL, median volume 0.80 mL) in 15.5 ± 17.5 discreet fluid pockets (median 12). The proportion of the fluid pockets larger than 1 mL was 9.6%, which contributed to 94.5% of the total fluid volume observed. No correlation was detected between all-ages and colonic fluid volume, nor was a difference in colonic fluid volumes observed based on sex, fed state or age group based on ICH-classifications. This study quantified fluid volumes within the paediatric colon, and these data will aid and accelerate the development of biorelevant tools to progress paediatric drug development for colon-targeting formulations.

Utilization of Diluted Compendial Media as Dissolution Test Solutions with Low Buffer Capacity for the Investigation of Dissolution Rate of Highly Soluble Immediate Release Drug Products

Research from the past decade has shown that the buffer capacities of intestinal fluids are much lower than those in the media used for dissolution test of many solid formulations. The purpose of this study was to elucidate the effect of buffer capacity on the dissolution profiles of highly soluble drug products, using metoclopramide (a biopharmaceutics classification system [BCS] class III drug) tablets as a model. The dissolution profiles of three metoclopramide products were obtained in Japanese pharmacopeia dissolution medium (pH 1.2 and 6.8), diluted medium with low buffer capacity comparable to that of gastrointestinal fluid, and other biorelevant media. One product showed slower dissolution in the medium with lower buffer capacity (bio-relevant, diluted compendial solution), but substantially similar dissolution in the compendial test solutions. Disintegration difference was implied to be involved in the different dissolution profiles depending on the medium buffer capacity. This study indicated the importance of media buffer capacity as a factor inducing different dissolution between products of highly soluble active pharmaceutical ingredients. The diluted compendial media would be a useful alternative to biorelevant media for the detection of the different formulation performances depending on the buffer capacities.

Current trends in drug metabolism and pharmacokinetics

Pharmacokinetics (PK) is the study of the absorption, distribution, metabolism, and excretion (ADME) processes of a drug. Understanding PK properties is essential for drug development and precision medication. In this review we provided an overview of recent research on PK with focus on the following aspects: (1) an update on drug-metabolizing enzymes and transporters in the determination of PK, as well as advances in xenobiotic receptors and noncoding RNAs (ncRNAs) in the modulation of PK, providing new understanding of the transcriptional and posttranscriptional regulatory mechanisms that result in inter-individual variations in pharmacotherapy; (2) current status and trends in assessing drug-drug interactions, especially interactions between drugs and herbs, between drugs and therapeutic biologics, and microbiota-mediated interactions; (3) advances in understanding the effects of diseases on PK, particularly changes in metabolizing enzymes and transporters with disease progression; (4) trends in mathematical modeling including physiologically-based PK modeling and novel animal models such as CRISPR/Cas9-based animal models for DMPK studies; (5) emerging non-classical xenobiotic metabolic pathways and the involvement of novel metabolic enzymes, especially non-P450s. Existing challenges and perspectives on future directions are discussed, and may stimulate the development of new research models, technologies, and strategies towards the development of better drugs and improved clinical practice.