Prednisolone-21-acetate

Absorption

Prednisolone acetate oral suspension given at a dose equivalent to 15mg prednisolone has a Cmax of 321.1ng/hr, a Tmaxof 1-2 hours, and an AUC of 1999.4ng*hr/mL. The absorption pharmacokinetics of prednisolone acetate are not significantly different from a comparable dose of prednisolone.

Toxicity

The oral LD50 of prednisolone acetate in mice is 1680 mg/kg. Patients experiencing an overdose of oral prednisolone acetate may experience an increased severity in the adverse effects of corticosteroids. Overdose of oral prednisolone acetate may be treated by gastric lavage or inducing vomiting if the overdose was recent, as well as supportive and symptomatic therapy. Chronic overdosage may be treated by dose reduction or treating patients on alternate days. An overdose by the ophthalmic route is not expected to cause problems.

Chemical properties

White or almost white, crystalline powder.

Originator

Sterane, Phipharmex ,US ,1955

The Uses of Prednisolone-21-acetate

Synthetic corticosteroid; metabolically interconvertible with prednisone.

The Uses of Prednisolone-21-acetate

glucocorticoid

Background

Prednisolone acetate is a prednisolone molecule bound to an acetate functional group by an ester bond.
Prednisolone acetate was granted FDA approval in 1955.

Indications

Prednisolone acetate is indicated as an anti-inflammatory or immunosuppressive agent for allergic, dermatologic, gastrointestinal, hematologic, ophthalmologic, nervous system, renal, respiratory, rheumatologic, or infectious conditions. Prednisolone acetate is also indicated in organ transplant patients, as well as endocrine or neoplastic conditions.

What are the applications of Application

Prednisolone 21-acetate is corticosteroid that is metabolically interconvertible with prednisone

Definition

ChEBI: Prednisolone acetate is a corticosteroid hormone.

Manufacturing Process

To a solution of 0.85 gram of 1,4-pregnadiene-11β,17α,21-triol-3,20-dione (prednisolone) in 5 ml of pyridine are added 3 ml of acetic anhydride. The reaction mixture is allowed to stand at room temperature overnight and is then diluted with ice water. The resulting precipitate is filtered from the mixture and recrystallized from acetone-hexane. There is recovered 0.45 gram of 1,4-pregnadiene-11β,17α,21-triol-3,20-dione 21-acetate, MP 235°239°C. On recrystallization, the MP rose to 237°-239°C.

brand name

Econopred (Alcon); Meticortelone (Schering); Omnipred (Alcon); Sterane (Pfizer).

Therapeutic Function

Glucocorticoid

Biological Activity

Prednisolone Acetate (Omnipred) is a synthetic corticosteroid that is a particularly potent immunosuppressant.

Pharmacokinetics

Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. Prednisolone acetate has a short duration of action as the half life is 2-3 hours. Corticosteroids have a wide therapeutic window as patients make require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections.

Clinical Use

For rheumatoid arthritis, rheumatic fever, lupus erythematosus, scleroderma, dermatomyositis, acute lymphoblastic leukemia, etc.

Metabolism

Prednisolone acetate undergoes ester hydrolysis to prednisolone. After this step, the drug undergoes the normal metabolism of prednisolone.
Prednisolone can be reversibly metabolized to prednisone which is then metabolized to 17α,21-dihydroxy-pregnan-1,4,6-trien-3,11,30-trione (M-XVII), 20α-dihydro-prednisone (M-V), 6βhydroxy-prednisone (M-XII), 6α-hydroxy-prednisone (M-XIII), or 20β-dihydro-prednisone (M-IV). 20β-dihydro-prednisone is metabolized to 17α,20ξ,21-trihydroxy-5ξ-pregn-1-en-3,11-dione(M-XVIII). Prednisolone is metabolized to Δ6-prednisolone (M-XI), 20α-dihydro-prednisolone (M-III), 20β-dihydro-prednisolone (M-II), 6αhydroxy-prednisolone (M-VII), or 6βhydroxy-prednisolone(M-VI). 6αhydroxy-prednisolone is metabolized to 6α,11β,17α,20β,21-pentahydroxypregnan-1,4-diene-3-one (M-X). 6βhydroxy-prednisolone is metabolized to 6β,11β,17α,20β,21-pentahydroxypregnan-1,4-diene-3-one (M-VIII), 6β,11β,17α,20α,21-pentahydroxypregnan-1,4-diene-3-one (M-IX), and 6β,11β,17α,21-tetrahydroxy-5ξ-pregn-1-en-3,20-dione (M-XIV). MVIII is metabolized to 6β,11β,17α,20β,21-pentahydroxy-5ξ-pregn-1-en-3-one (M-XV) and then to MXIV, while MIX is metabolized to 6β,11β,17α,20α,21-pentahydroxy-5ξ-pregn-1-en-3-one (M-XVI) and then to MXIV. These metabolites and their glucuronide conjugates are excreted predominantly in the urine.

Purification Methods

Recrystallise prednisolone acetate from EtOH, Me2CO, Me2CO/hexane, and it has UV with max at 243nm in EtOH. [Joly et al. Bull Soc Chim Fr 366 1958; Herzog et al. J Am Chem Soc 77 4781 1955, Beilstein 8 IV 3468.]