Search results for "Colonic absorption"
showing 3 items of 3 documents
Preclinical models for colonic absorption, application to controlled release formulation development.
2018
Oral controlled release (CR) formulations have many benefits and have become a valuable resource for the local and systemic administration of drugs. The most important characteristic of these pharmaceutical products is that drug absorption occurs mainly in the colon. Therefore, this review analyses the physiological and physicochemical features that may affect an orally administered CR product, as well as the different strategies to develop a CR dosage form and the methods used to evaluate the formulation efficacy. The models available to study the intestinal permeability and their applicability to colonic permeability determinations are also discussed.
Studies on the reliability of a bihyperbolic functional absorption model. II. Phenylalkylamines
1987
Evidence is given that demonstrates the reliability of the bihyperbolic equation, proposed by Pla-Delfina and Moreno, in fitting the correlation between absorption rate constants (ka) found in the small intestine and in the colon of the living anesthetized rat, and partition constants (1/R.F−1), for a series of phenylalkylamines, a group of compounds which differ largely from others which have been tested. Emphasis is laid on the nonexistence of an optimum of lipophilicity for intestinal absorption/partition correlation: This feature makes inapplicable the probabilistic approaches to the reported data.
IMI – Oral biopharmaceutics tools project – Evaluation of bottom-up PBPK prediction success part 3: Identifying gaps in system parameters by analysin…
2016
Three Physiologically Based Pharmacokinetic software packages (GI-Sim, Simcyp® Simulator, and GastroPlus™) were evaluated as part of the Innovative Medicine Initiative Oral Biopharmaceutics Tools project (OrBiTo) during a blinded “bottom-up” anticipation of human pharmacokinetics. After data analysis of the predicted vs. measured pharmacokinetics parameters, it was found that oral bioavailability (Foral) was underpredicted for compounds with low permeability, suggesting improper estimates of intestinal surface area, colonic absorption and/or lack of intestinal transporter information. Foral was also underpredicted for acidic compounds, suggesting overestimation of impact of ionisation on pe…