Analytical equivalence between standard and refined lethality neutralization protocols for snake antivenoms

Area of Science:

• Pharmacology
• Toxicology
• Veterinary Medicine

Background:

• Murine lethality neutralization assays are crucial for snake antivenom quality control.
• Current standard protocols raise concerns regarding animal welfare due to prolonged observation periods and lack of analgesia.

Purpose of the Study:

• To evaluate a refined protocol for snake antivenom potency testing that incorporates analgesia and a shortened endpoint.
• To determine if the refined protocol maintains analytical reliability comparable to the standard protocol.

Main Methods:

• Comparison of median lethal dose (LD50) and median effective dose (ED50) determinations between a refined protocol (6-hour endpoint, tramadol analgesia) and the standard protocol (48-hour endpoint, no analgesia).
• Assays involved multiple antivenom batches, venoms, administration routes, and mouse weight ranges.
• Analytical validation included linearity, accuracy, and intermediate precision assessments.

Main Results:

• Median lethal dose (LD50) values at 6 hours were slightly higher than at 48 hours, with one significant difference observed.
• No significant differences in median effective dose (ED50) values were found between the 6-hour and 48-hour endpoints across various conditions.
• The refined protocol demonstrated strong correlation with the standard protocol and met analytical validation criteria (linearity, accuracy, precision).

Conclusions:

• The refined protocol provides equivalent snake antivenom potency estimates to the standard protocol.
• Adoption of the refined protocol can reduce animal pain and distress in routine antivenom quality control.
• The refined protocol supports improved animal welfare without compromising analytical reliability.