Related Experiment Video
Updated: Jul 6, 2026

Continuous Flow Chemistry: Reaction of Diphenyldiazomethane with p-Nitrobenzoic Acid
Published on: November 15, 2017
Controlled flow-through dissolution methodology: a high-performance system
Larry E Stevens1, Paul J Missel, Alan L Weiner
1Alcon Research, Ltd., Fort Worth, TX, USA. larry.stevens@alconlabs.com
Abstract:
Measuring release rates using compendial systems, especially for sparingly soluble compounds, often produces complex results with less than desired precision and lacks relevance to key formulation or biological parameters. A flow-through approach was used by focusing on convective diffusion and controlling certain key physical-chemical factors. Results are presented for an automated multisample flow-through system that displays significant advantages over compendial (1) stirred and (2) flow-through systems. Advantages include precision, physicochemical, and in vivo relevance, along with analytical and formulation sensitivity. The convective diffusion/dissolution process was also simulated by using finite element modeling with predictions agreeing with measurements to within a few percent.
Related Concept Videos
In Vitro Drug Dissolution: Compendial Testing Models II
Theories of Dissolution: Diffusion Layer Model
This process starts with a thin layer, saturated with the drug, forming at the interface between the solid and liquid. The solute then diffuses from this layer into the main solution. The Noyes-Whitney equation suggests that the rate of dissolution relies on the diffusion...
In Vitro Drug Dissolution: Alternative Methods
In Vitro Drug Dissolution: Compendial Testing Models I
Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
Drug Dissolution: Requirements and Profile Comparison
