Apr. Huybrecht T'JOLLYN
Huybrecht T'Jollyn is doing research at the Laboratory for Medical Biochemistry and Clinical Analysis
Main research interests : Pharmacokinetics and Modelling
In clinical development candidate drugs are usually being tested in healthy volunteers and patients to study the pharmacodynamics and pharmacokinetics after a single dose. Mainly ethical, economical and practical reasons are at the root of the hampered research in pediatric populations. If such PK/PD data in pediatrics are required then first dosage is assessed empirically.
It is known to date that the physiology of children changes vastly per individual child and over time so that the absorption, distribution, metabolism and excretion of drugs differ greatly and are much more variable when compared to adults. Specific argumentation concerning the dosage adjustment for children is frequently missing because pharmacokinetic-mechanistic knowledge is inadequate.
Several ways of predicting the PK/PD in children are being explored. On one hand extrapolation techniques based on body weight (BW) and body surface area (BSA) are used but their poor results ask for better and more complex models to predict drug disposition in children. On the other hand in silico prediction tools (in this context PBPK-models) can be used to make more complex predictions. Although theoretically more designated there is still a lot of validation and optimization to be done to get the predictions as close to the in vivo situation as possible.
This PhD will focus on validating “extrapolation techniques” and “in silico prediction tools” using a top-down as well as a bottom-up approach. To make this validation possible we have a reference data set of pediatric PK data for tramadol and propofol. Through additional in vitro work identification of the differences between observed and predicted values will enable us to mechanistically improve the performance of the predictions.
Laboratory of Medical Biochemistry and Clinical Analysis, Department of Bioanalysis
Campus Heymans
Ghent University
Ottergemsesteenweg 460
B-9000 Ghent
BELGIUM
Tel. : + 32 (0)9 264 81 14
Fax : + 32 (0)9 264 81 97
E-mail : Huybrecht T'Jollyn