International Journal of Pharmacy and Pharmacology

ISSN 2326-7267

International Journal of Pharmacy and Pharmacology ISSN: 2326-7267 Vol. 2 (6), pp. 001-005, June, 2011. © International Scholars Journals

Full Length Research Paper

Comparison of the physical and chemical changes of magistral suspension with anesthesin and aethenamine after date of expiration

Rade Injac

Faculty of Pharmacy, Institute of Pharmaceutical Biology, University of Ljubljana, Askerceva 7, 1000 Ljubljana, Slovenia. E-mail: [email protected]. Tel: +386 41 964462. Fax: + 386 1 4258031.

Accepted 13 April, 2011

Abstract

This study reports the differences in physical and chemical stability of suspension with dissolved and non dissolved main active compound. In the first case it is methenamine and the other one is anesthesin. At the same time we analyzed two fresh and two 18-months old formulations of both magistral preparations. Anesthesin suspensions did not show any significant physical or chemical changes in 18 months except changes in appearance. On the other hand suspension with methenamine showed as very unstable system. Methenamine was hydrolyzed in water and ammonia and formaldehyde were determined as degradation products. Level of methenamine in preparations after 18 months was 84.6 ± 1.1%. Also the value of water was slightly decreased in old formulation with methanamine, which indicates a physical unstable system.

Key words: Methenamine, anesthesin, suspensions, magistral preparation stability.