Abstract
A rotating diffusion cell has been used to determine the kinetics and thermodynamics associated with the transport of methyl nicotinate (3-pyridine-carboxylic acid, methyl ester) across an aqueous phase/n-octanol liquid-liquid interface. The selection of the organic phase reflects the frequent successful use of octanol to simulate the properties of biomembranes and biophases in general. Hence the experiments are designed to probe, under carefully controlled conditions in the laboratory, a physicochemical event common to passive membrane transport and other pharmaceutically relevant partitioning processes. The results demonstrate that a significant free energy input is required for interfacial transfer and that the enthalpic and entropic contributions to the barrier depend upon the direction of partitioning. The kinetics of the liquid-liquid transfer process imply that interfacial transport has the potential to be rate-limiting in many biological and pharmaceutical systems.
| Original language | English |
|---|---|
| Pages (from-to) | 129-137 |
| Number of pages | 9 |
| Journal | International Journal of Pharmaceutics |
| Volume | 19 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Apr 1984 |
Bibliographical note
Funding Information:The authorst hank Dr. Robert Him for assistancea nd Dr. Jonathan Hadgraft for his helpful commentsa nd advice. Financial support for this work was provided by grants to R.H.G. from the Academic Senateo f the University of California, San Francisco, from the National Institutes of Health (AA05781-01) and from the Donors of the Petroleum ResearchF und administeredb y the American Chemical Society( PRFI 3860-G5j.
ASJC Scopus subject areas
- Pharmaceutical Science