Related Experiment Video
Updated: Oct 1, 2026

Coherent anti-Stokes Raman Scattering (CARS) Microscopy Visualizes Pharmaceutical Tablets During Dissolution
Published on: July 4, 2014
Release and absorption characteristics of novel theophylline sustained-release formulations: in vitro-in vivo
1Department of Pharmacy, School of Pharmacy, Hebrew University, Jerusalem, Israel.
Abstract:
Five new experimental sustained-release (SR) formulations of theophylline, T-1, T-1-A, T-2, T-2-A, and T-2-E, in a matrix tablet form with a protein were developed. The in vitro release of theophylline from these novel experimental formulations and two commercial (Theotrim and Theo-Dur) SR formulations, was studied for 2 hr immersed in simulated gastric fluid TS, followed by an additional 10 hr immersed in simulated intestinal fluid TS. Like Therotrim and Theo-Dur, theophylline release profiles from all the novel experimental formulations were smooth, controlled, and unaffected by changes in the pH and the proteolytic enzyme content of the incubation media. Pharmacokinetic evaluation of T-1, T-1-A, T-2-A. Theotrim, and Theo-Dur was carried out in five dogs and six healthy human volunteers under fasting conditions, using immediate-release aminophylline tablets as controls. Pharmacokinetic analysis by the Wagner-Nelson procedure revealed sustained-release absorption characteristics for all the formulations with the exception of the immediate release aminophylline tablet. For each of the formulations tested, the regression analysis results of the percentage of theophylline absorbed in dogs or humans against the mean percentage released in vitro, at the corresponding times, indicated a high correlation. These data imply that the in vivo release profiles under fasting conditions in the gastrointestinal tract of dogs and humans may be similar to those in the in vitro studies.
More Related Videos
Related Concept Videos
Methods for Studying Drug Absorption: In vitro
The diffusion cell method uses a two-compartment cell, including a donor compartment with the drug solution, which simulates the environment where the drug is applied, and a receptor compartment with a buffer solution, which simulates the environment...
In Vitro Drug Release Testing: Overview, Development and Validation
Drug Product Performance: In Vitro–In Vivo Correlation
IV Infusion to Oral Dosing: Conversion Methods
Modified-Release Drug Delivery Systems: Bioavailability
Modified-Release Drug Delivery Systems: Drug Release Characteristics

