AbstractThe impact of nanoemulsification on the antinociceptive effect of benzopyran HP1 in a mice hot plate test was investigated. For comparison, the same experiments were performed with HP1-free form. The durability of the antinociceptive effect was analyzed at 60, 120 and 180 min. The results revealed that HP1 was successfully incorporated into a nanoemulsion system, given its high solubility in the oil phase. Regarding the pharmacological effect, HP1 (15, 30, 45, and 60 mg/kg, p.o.), both forms, displayed the pattern of a bell-shaped dose-response curve. HP1-loaded nanoemulsion displayed the maximal antinociceptive effect at a lower dose than the HP1-free form. The highest effect of the free compound was observed at 45 mg/kg, while the HP1-loaded nanoemulsion displayed the same effect at 30 mg/kg. These results suggest that the observed effect might be attributable to an increase in solubility and, thus, the enhancement of compound absorption. Regarding the durability of the antinociceptive effect, the outcomes demonstrated that the HP1-free form lost its antinociceptive effect at 120 min, while the HP1-loaded nanoemulsion kept its effect until 180 min. These findings corroborate literature data, where studies have demonstrated absorption enhancement when a compound was loaded in a nanoemulsion system.