A vaccine preparation consisting of tetanus toroid (TT) encapsulated i
n biodegradable poly (D,L-Lactide) glycolide polymer has been develope
d. The toxicity of the preparation was evaluated in adult male and fem
ale Wistar rats injected IM with 20, 100 and 200 Lf tetanus toroid, in
polymer in 0.5 ml vehicle. No adverse effect of the vaccine could be
seen, except for a granulomatous reaction at the site of injection. Th
e vaccine was considered safe based on the findings in rats of both se
xes.