Bentonite-induced rat paw oedema as a tool for simultaneous testing of prophylactic and therapeutic effects of anti-inflammatory and other drugs.

The possibility of screening simultaneously the prophylactic and therapeutic effects of a single dose of anti-inflammatory drugs was further tested. Bentonite oedema was induced in the left paw (0.05 ml of 5% bentonite gel subcutaneously). After the measurement of its size in the 23rd h, the rats were given the test drugs (i.m. or p.o.) and 1 h thereafter, bentonite oedema was induced in the right paw. Some of the drugs suppressed the oedema both prophylactically and therapeutically (steroidal and some nonsteroidal anti-inflammatory drugs, sodium aurothiomalate etc.), some others suppressed it only prophylactically (some derivatives of pyrazolone etc.) and some of the remaining drugs tested had no effect at all on the oedema after a single administration. Advantages and limitations of this method are discussed.