What is the optimum concentration of m-cresol in antivenoms?

Abd-Elsalam MA (1), Abdoon N (1), Al-Ahaidib MS (1)

(1) National Antivenom and Vaccine Production Center, King Abdulaziz Medical City, King Fahad National Guard Hospital, Riyadh, Kingdom of Saudi Arabia

Abstract: Antivenoms against snake and scorpion envenomations are usually equine in nature and composed mostly of F(ab`)2; additionally, phenol and m-cresol are mainly employed for their preservation. Although there is no study on this subject, m-cresol is utilized by most manufacturers in a concentration that ranges from 0.15 to 0.35 g%. Decreasing the concentration of m-cresol to its minimal effective level may protect victims from its toxic effects and keep the antivenom stable during its shelf life without forming any aggregates. In the present work, different concentrations of m-cresol, ranging from 0.1 to 0.35 g%, were used with some selected batches of snake and scorpion antivenoms. A low concentration of 0.15 g% showed an acceptable preserving result that complies perfectly with antimicrobial specifications stated by the British Pharmacopoeia. Tested antivenoms (in 12 batches), when kept in a cold room for 39 months (more than their shelf life), retained their physical, chemical and microbiological activities according to the specifications of pharmacopeias. The present data demonstrated that reduction of m-cresol concentration to 0.15 g% in case of equine F(ab`)2 antivenoms will improve safety of such preparations and preserve their stability during their shelf life.

Key words: antivenoms, preservative, m-cresol, stability

ACKNOWLEDGEMENTS

The authors thank professor Mohammad Shohayeb, University of Tanta, Egypt, for his valuable suggestions and comments on this work.

COPYRIGHT

© CEVAP 2011

SUBMISSION STATUS

Received: April 24, 2010.

Accepted: October 26, 2010.

Abstract published online: November 5, 2010.

Full paper published online: February 28, 2011.

CONFLICTS OF INTEREST

There is no conflict.

ETHICS COMMITTEE APPROVAL

The tests performed in this research are under the guidelines of the Ethics Committee for Safe Animal Handling of the Kingdom of Saudi Arabia.

CORRESPONDENCE TO

MOHAMMAD A. ABD-ELSALAM, National Antivenom and Vaccine Production Center, King Abdulaziz Medical City, King Fahad National Guard Hospital, P.O. Box 22490, Riyadh, 11426, Kingdom of Saudi Arabia. Email: atefabuzeid@yahoo.com or abuzeidm@hotmail.com.