The active ingredient in RAYOS is prednisone (a corticosteroid). Corticosteroids are adrenocortical steroids, both naturally occurring and synthetic. The molecular formula for prednisone is C₂₁H₂₆O₅. The chemical name for prednisone is 17,21-dihydroxypregna-1,4diene-3,11,20-trione, and the structural formula is:

Prednisone is a white to practically white, odorless, crystalline powder and has a molecular weight of 358.43. Prednisone is very slightly soluble in water; slightly soluble in alcohol, chloroform, dioxane, and methanol.

RAYOS is a delayed-release prednisone tablet. It consists of a prednisone-containing core tablet in an inactive shell, which delays the onset of in vitro drug dissolution by approximately 4 hours. Each tablet contains 1 mg, 2 mg, or 5 mg of prednisone, with the following inactive ingredients: dibasic calcium phosphate dihydrate, colloidal silicon dioxide, croscarmellose sodium, glycerol dibehenate, lactose monohydrate, magnesium stearate, povidone, yellow ferric oxide, and red ferric oxide.

Last reviewed on RxList: 9/4/2012
This monograph has been modified to include the generic and brand name in many instances.