Description
Halobetasol propionate is a new ultra-potent topical corticosteroid exhibiting both
antiinflammatory and antihyperplasia properties. The compound is recommended for
the treatment of moderate to severe corticosteroid-responsive dermatoses and appears
to be particularly effective in patients with plaque psoriasis. It inhibits dermatitis induced by ultraviolet light in guinea pigs (ED50 = 1.45 μg/animal) and by oxazolone in mice (ED50 = 0.8 μg/animal). Halobetasol propionate also has anti-inflammatory effects on croton oil-induced ear edema in rats (ED50s = 10 μg/ml and 0.5 μg/ear) and mice (ED50s = 1.2 and <0.32 μg/ear after 6 and 24 hours of treatment, respectively). Topical formulations containing halobetasol propionate have been used for inflammatory and pruritic dermatitis.
Chemical Properties
White Solid
Originator
Ciba-Geigy (Switzerland)
Uses
Halobetasol propionate is a corticosteroid (cortisone-like medicine or steroid). As an anti-inflammatory drug, halobetasol topical is used to help relieve redness, itching, swelling, or other discomfort caused by certain skin conditions. It is also used to treat plaque psoriasis.This medicine is available only with doctor's prescription.
Definition
ChEBI: Ulobetasol propionate is a corticosteroid hormone.
brand name
Ultravate (Westwood-Squibb).
Synthesis
Halobetasol propionate is synthesized from 17-hydroxy-9,11-epoxy-16-methylpregna-1,4-diene-3,20-dione-21-acetate in multiple steps. Key steps include: 1) Introduction of a double bond using conc. H2SO4 in isopropylidene acetate. 2) 6-Fluorination using F-TEDA. 3) 9,11-Ring-opening fluorination with 70% HF to give difluprednate 21-acetate. 4) Basic hydrolysis to remove the 21-acetate group, yielding difluprednisolone. 5) Reaction with an orthoester to protect the 17-hydroxy group. 6) Mesylation of the 21-hydroxy group. 7) Heating with LiCl in DMA for 21-chloro substitution, yielding halobetasol propionate.
