DESCRIPTION SECTION
Budesonide, the active ingredient of ENTOCORT® EC capsules, is a synthetic corticosteroid. It is designated chemically as (RS)-11β, 16α, 17,21-tetrahydroxypregna-1,4-diene-3,20-dione cyclic 16,17-acetal with butyraldehyde. Budesonide is provided as a mixture of two epimers (22R and 22S). The empirical formula of budesonide is C25H34O6 and its molecular weight is 430.5. Its structural formula is:
Budesonide is a white to off-white, tasteless, odorless powder that is practically insoluble in water and heptane, sparingly soluble in ethanol, and freely soluble in chloroform. Its partition coefficient between octanol and water at pH 5 is 1.6 x 103 ionic strength 0.01.
Each capsule contains 3 mg of micronized budesonide with the following inactive ingredients: ethylcellulose, acetyltributyl citrate, methacrylic acid copolymer type C, triethyl citrate, antifoam M, polysorbate 80, talc, and sugar spheres. The capsule shells have the following inactive ingredients: gelatin, iron oxide, and titanium dioxide.
CLINICAL PHARMACOLOGY
Budesonide has a high topical glucocorticosteroid (GCS) activity and a su