Effect of pH on the release and permeation of diazepam from sustained-release dosage forms

• Type: Article in International Scientific Journal
• Date: 1997

Authors

Ferreira, DC (Author) FFUP; Costa, P (Author) FFUP; Sousa Lobo, JM (Author) Other

Journal

Title: Pharmaceutical Sciences

Vol. 3

Pages: 171-173

ISSN: 1356-6881

Publisher: Royal Pharmaceutical Society of Great Britain

Indexing

ISI Web of Knowledge

Scopus - 0 Citations

Other information

Authenticus ID: P-007-7R3

Abstract (EN): The aim of the present study was to investigate the in-vitro release rate of diazepam from a commercially available sustained-release preparation using the flow-through dissolution apparatus (USP apparatus 4) and a dissolution permeation apparatus developed in these laboratories, and to investigate the in-vitro permeation rate of diazepam using the latter. The release profiles of diazepam at pH 6.9 and 7.2 were very similar for both apparatuses tested. At pH 1.5 the release of diazepam is much lower, and at pH 4.5 the release is the lowest (20-25%). The permeation profiles of diazepam for the dissolution permeation apparatus at pH 6.9 and 7.2 are very similar. At pH 1.5 the permeation of diazepam is much lower and at pH 4.5 the permeation is practically undetectable, presumably because of the very low diazepam concentration in the donor compartment. As the pH of enteric fluids may vary depending on several physiological conditions, diazepam release and absorption must be conditional on previous study of those pH variations. Both apparatuses used showed a similar release profile for the various release conditions, and we can therefore consider them as equivalent for this kind of study.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 3