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.
Highlights
Antivenoms are refined and concentrated preparations of equine serum globulins – mostly F(ab)2 – obtained by fractionating blood from healthy horses that were previously immunized with different type of venoms [1, 2]
The strains of challenge organisms used for testing the antimicrobial efficacy of the preservative (m-cresol) were: Pseudomonas aeruginosa ATCC 9027, Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633, Candida albicans ATCC 10231 and Aspergilus niger ATCC 16404
M-cresol is employed by many antivenom manufacturers as preservative in their preparations, no clear recommendation was found in North American or British pharmacopoeias regarding the actual concentration that should be used to keep the product sterile and stable over the period of its shelf life
Summary
Antivenoms are refined and concentrated preparations of equine serum globulins – mostly F(ab)2 – obtained by fractionating blood from healthy horses that were previously immunized with different type of venoms [1, 2]. M-cresol, a phenol derivative, is frequently utilized as preservative in numerous antivenom preparations in concentrations that range between 0.15 and 0.35 g% [4, 7, 13]. Despite their efficacy as additive, the use of these agents involves the possibility of some adverse effects. It is quite curious that such a wide range of preservatives employed in different concentrations in antivenoms was not tested to find the minimum concentration of phenols that may be utilized to restore maximum preserving activity and to maintain stability over the shelf life. Improvements in antivenom quality will be focused on the obtainment of a more stable product in compliance with good manufacturing practices and at an affordable quality
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
