Developmental Changes in the Processes Governing Oral Drug Absorption

Pharmacokinetic and pharmacodynamic principles: unique considerations for optimal design of neonatal clinical trials

Core clinical pharmacology principles must be considered when designing and executing neonatal clinical trials. In this review, the authors discuss important aspects of drug dose selection, pharmacokinetics, pharmacogenetics and pharmacodynamics that stakeholders may consider when undertaking a neonatal or infant clinical trial.

Biopharmaceutical considerations in paediatrics with a view to the evaluation of orally administered drug products - a PEARRL review

OBJECTIVES

In this review, the current biopharmaceutical approaches for evaluation of oral formulation performance in paediatrics are discussed.

KEY FINDINGS

The paediatric gastrointestinal (GI) tract undergoes numerous morphological and physiological changes throughout its development and growth. Some physiological parameters are yet to be investigated, limiting the use of the existing in vitro biopharmaceutical tools to predict the in vivo performance of paediatric formulations. Meals and frequencies of their administration evolve during childhood and affect oral drug absorption. Furthermore, the establishment of a paediatric Biopharmaceutics Classification System (pBCS), based on the adult Biopharmaceutics Classification System (BCS), requires criteria adjustments. The usefulness of computational simulation and modeling for extrapolation of adult data to paediatrics has been confirmed as a tool for predicting drug formulation performance. Despite the great number of successful physiologically based pharmacokinetic models to simulate drug disposition, the simulation of drug absorption from the GI tract is a complicating issue in paediatric populations.

SUMMARY

The biopharmaceutics tools for investigation of oral drug absorption in paediatrics need further development, refinement and validation. A combination of in vitro and in silico methods could compensate for the uncertainties accompanying each method on its own.

Similarities and differences in gastrointestinal physiology between neonates and adults: a physiologically based pharmacokinetic modeling perspective

Physiologically based pharmacokinetic (PBPK) modeling holds great promise for anticipating the quantitative changes of pharmacokinetics in pediatric populations relative to adults, which has served as a useful tool in regulatory reviews. Although the availability of specialized software for PBPK modeling has facilitated the widespread applications of this approach in regulatory submissions, challenges in the implementation and interpretation of pediatric PBPK models remain great, for which controversies and knowledge gaps remain regarding neonatal development of the gastrointestinal tract. The commentary highlights the similarities and differences in the gastrointestinal pH and transit time between neonates and adults from a PBPK modeling prospective. Understanding the similarities and differences in these physiological parameters governing oral absorption would promote good practice in the use of pediatric PBPK modeling to assess oral exposure and pharmacokinetics in neonates.