Enteric Solid Dispersion of Cyclosporin A (CyA) Having Potential to Improve Availability of CyA in Rabbit

Abstract

The availability of cyclosporin A (CyA) administered as an enteric solid dispersion preparation of which the composition is CyA : HCO-60^[○!R] : HP-55^[○!R]=1 : 2 : 8 was evaluated in rabbits. The additives are surfactant (polyoxyethy-lated, 60μmol, castor oil derivative, HCO-60^[○!R]) and enteric coating material (hydroxypropylmethyl cellulose phthalate, HP-55^[○!R]), which are generally used as pharmaceutical additives. Both the systemic and lymphatic availabilities of CyA from this solid preparation were measured in rabbits after intrastomach administration, 7mg CyA/kg, and were compared with those from conventional oily solution, Sandimmun^[○!R]. The mean systemic availability of CyA from the solid preparation was 57% which is about 1.5 times greater than that obtained from Sandimmun. THe amounts of CyA transferred into the thoracic lymphatics within 12h from solid dosage form and Sandimmun are 0.62±0.16(S.D.)% and 0.13±0.05% of the administered CyA dose. These results support the usefulness of the new solid dosage form of CyA.