The effect of carriers--potato starch, sodium carboxymethyl cellulose, sodium alginate, and hydrophilic agents--polyethyleneglycol 1500 (PEG 1500), PEG 4000, glyceryl monostearate (MSG), Tween 65, on bioavailability of papaverine from spheres were studied on rabbits. The data of pharmacokinetics parameters as absorption lag time, maximum plasma concentration (Cmax), time to peak concentration, absorption rate constant, elimination rate constant, bioavailability (F) depend on drug-carrier-hydrophilic agent composition. Potato starch-PEG 4000, potato starch-MSG, NaCMC-PEG 1500 spheres show best F-parameters of papaverine respectively 96%, 89%, 88%, Cmax 19.7, 21.3, 18.6 micrograms/ml reached in about 2 h.