Results from this study in which the impact of various media parameters on drug release of EC aspirin formulations was systematically screened clearly show that when developing predictive dissolution tests, it is important to simulate the ionic composition of intraluminal fluids as closely as possible.

Purpose The objective of the present work was to screen whether a novel pediatric hydrocortisone granule formulation can be co-administered with common food matrices and liquids. Methods Pediatric hydrocortisone granules were studied using a biopredictive in vitro approach. Experiments included an in situ chemical compatibility study of active ingredient and drug product with liquid dosing vehicles and soft foods commonly ingested by infants, pre-school- and school children. Drug solubility and stability experiments in the different vehicle types and, drug release/dissolution experiments mimicking age-related pediatric gastric conditions after administering the hydrocortisone granules together with the dosing vehicles and after different exposure/mixing times were performed. Results In the simulated dosing scenarios applied in dissolution experiments, in vitro dissolution in gastric conditions was rapid and complete. Results of the chemical compatibility/stability studies indicated that mixing with the different dosing vehicles studied should not be an issue regarding drug degradation products. Conclusions A novel in vitro approach ensuring a proper risk assessment of the use of dosing vehicles in the administration of pediatric dosage forms was established and applied to a novel pediatric hydrocortisone drug product. The studied dosing vehicles were shown to not alter performance of the drug product and are thus considered suitable for administration with hydrocortisone granules.

Predictive in vitro test methods addressing the parameters relevant to drug release in the pediatric gastrointestinal tract could be an appropriate means for reducing the number of in vivo studies in children. However, dissolution models addressing the particular features of pediatric gastrointestinal physiology and typical pediatric dosing scenarios have not yet been described. The objective of the present study was to combine the knowledge on common vehicle types and properties and current information on pediatric gastrointestinal physiology to design a dissolution model that enables a biorelevant simulation of the gastrointestinal conditions in young children. The novel dissolution setup consists of a miniaturized dissolution system allowing the use of small fluid volumes, physiological bicarbonate-based test media, and a proper pH control during the experiment using a pHysio-stat® device. Following design and assembly of the novel in vitro setup, a set of experiments screening in vitro drug release from a valproate-extended release formulation under typical dosing conditions in infants was performed. In vitro drug release profiles indicated a controlled drug release of the test product over 12 h and were in good agreement with information given in the Summary of Product Characteristics and the Patient Information Leaflet, as well as with results from an in vivo food effect study performed with the same product and reported in the literature. The new dissolution setup thus represents a promising in vitro screening tool in the development of pediatric dosage forms and may help to reduce the number of pharmacokinetic studies in children.

Drug release and availability at the site of action are the major factors determining the clinical response for locally-acting gastrointestinal (GI) drug products. The present work focused on the prediction of site and extent of in vivo mesalazine release after oral administration to a variety of subjects using individualized in vitro drug release experiments. First, experiments mimicking GI passages in average adult subjects were performed. Then, results from a study screening fasted in vivo pH and transit profiles in individual subjects were translated into a novel in vitro dissolution model enabling to mimic individual GI pH-profiles and transit times with physiologically relevant dissolution media. A selection of monolithic and multiparticulate mesalazine formulations with pH-dependent and pH-independent drug release was screened with the novel dissolution model. Results of the study indicate that dosage form performance can be significantly different in individual subjects and highlight the importance of addressing individual physiological parameters relevant to intraluminal drug release when the aim is to predict the in vivo performance of locally-acting mesalazine formulations in individual patients. The novel in vitro dissolution approach thus represents a valuable tool for both improving individual oral therapy with locally-acting GI drug products and assessing bioequivalence of these formulations.

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