Fig. 1. Antinociceptive activity of paracetamol (APAP) following (A ) oral or (B ) intravenous route of administration on hind paw biting and licking time produced by 2.5% formalin. The two phases of nociceptive behavior were monitored 0 to 5 min (phase 1) and 20 to 40 min (phase 2) after intraplantar formalin injection (50 μL). The results are expressed as mean ± standard error of mean of the cumulative of biting and licking time during each phase. *P < 0.05 compared with the control group using analysis of variance followed by Student-Newman-Keuls test (n = 8).