Using Physiologically Based Pharmacokinetic (PBPK) Modelling to Gain Insights into the Effect of Physiological Factors on Oral Absorption in Paediatric Populations.

Paediatric pharmaceutics has become an important topic, but currently, there is an incomplete knowledge of paediatric gastrointestinal physiology and adequate biopharmaceutical tools still have to be developed. The present study aimed to increase the understanding of oral drug absorption in paediatric populations by using physiologically based pharmacokinetic (PBPK) modelling and in vitro dissolution testing. The oral absorption of two model compounds, sotalol and paracetamol, was studied by collection of reported pharmacokinetic profiles from adult and paediatric subjects. A PBPK model based on input parameters collected from the literature was first developed and validated in adults before being extrapolated to paediatric age groups. The accuracy of the model simulations was assessed by comparison to the observed pharmacokinetic profiles, and in the case of discrepancy, further investigations were made via parameter sensitivity analysis and in vitro dissolution testing. The PBPK models accurately predicted sotalol and paracetamol exposure in adult populations. An accurate simulation was also obtained after model extrapolation to children older than 2 years of age. However, the simulation in infants and newborns resulted in a discrepancy, which was further analysed. Dissolution testing suggested no significant difference in the drug release rate between paediatric and adult age groups. In contrast, mean gastric emptying time seemed to be underestimated in infants and newborns, and optimisation of this input parameter improved the prediction of the model. Considering age-specific differences in gastrointestinal tract physiology should improve prediction of drug absorption in paediatric patients.

In vitro inhibitory potential of Cynara scolymus, Silybum marianum, Taraxacum officinale, and Peumus boldus on key enzymes relevant to metabolic syndrome.

Boldocynara®, a proprietary dietary supplement product consisting of the plants Cynara scolymus, Silybum marianum, Taraxacum officinale, and Peumus boldus, used to promote functions of the liver and the gallbladder. It was the aim of the present study to look from a different perspective at the product by investigating the in vitro potential of Boldocynara® as a combination product and its individual extracts on key enzymes relevant to metabolic syndrome. Peumus boldus extract exhibited pronounced inhibitory activities on α-glucosidase (80% inhibition at 100 µg/ml, IC50: 17.56 µg/ml). Silybum marianum had moderate pancreatic lipase (PL) inhibitory activities (30% at 100 µg/ml) whereas Cynara scolymus showed moderate ACE inhibitory activity (31% at 100 µg/ml). The combination had moderate to weak effects on the tested enzymes. In conclusion, our results indicate some moderate potential of the dietary supplement Boldocynara® and its single ingredients for the prevention of metabolic disorders.