INFLUENCE OF DISSOLUTION RATE OF SPARINGLY SOLUBLE DRUGS ON CORNEAL PERMEABILITY INVITRO

The effects of particle size and dissolution rate of sparingly soluble drugs on their permeability coefficients were studied using excised pig cornea. Two wet sieve fractions, ≪ 5 and 10-15 μm, of griseofulvin and prednisolone acetate were tested. The results show that there is no significant difference between the permeability coefficients of the two fractions. The dissolution rates of both sieve fractions were greater than the permeability rates and thus did not represent a rate-limiting step. Prednisolone acetate was fully hydrolyzed during passage through the cornea and only prednisolone was detected in the receiving compartment. The deviation from linear steady-state permeation at around 200 min suggests that the enzymatic process which hydrolyzes prednisolone acetate is saturable. © 1990.