Andolast (CR 2039) (free base) is an anti-allergic agent. Andolast can inhibit cAMP-phosphodiesterase with an IC 50 value of 50 μM. Andolast can be used for the research of asthma. In Vivo Andolast (CR 2039) (i.v. or i.m.) inhibits rat passive cutaneous anaphylaxis (PCA) with an ED 50 of 0.1 mg/kg . CR 2039 (10-100 mg/kg; i.v. or i.m.) inhibits the microvascular permeability changes in a model of allergic conjunctivitis in sensitized guinea-pigs . CR 2039 (0-1000 μM; i.v.) inhibits dose dependently guinea-pig lung cAMP-phosphodiesterase with an IC 50 value of 50 μM . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: Male Hartley guinea-pigs (300-500 g) Dosage: 10-100 mg/kg Administration: I.M; I.V. Result: Showed dose-related significant protection against lgE-dependent bronchial anaphylaxis induced by aerosolized antigen in anesthetized guinea-pigs. Delayed dose dependently the onset of bronchoconstriction induced by aerosolized antigen. Form:Solid