Antinociceptive activity of dalargin (7.5 mg/kg) adsorbed on poly(butyl)cyanoacrylate nanoparticles with different coating was studied on outbred albino mice by the tail-flick test. poly(butyl)cyanoacrylate nanoparticles without coating did not increase the antinociceptive activity of dalargin and hence, did not increase its transport across the blood-brain barrier. poly(butyl)cyanoacrylate nanoparticles coated with apolipoprotein B, apolipoprotein E, and polysorbate 80 increased the transport of dalargin across the blood-brain barrier. Delivery of dalargin to the brain was most effective in case of using poly(butyl)cyanoacrylate nanoparticles with polysorbate 80 coating and subsequent supercoating with apolipoprotein E.