Calcipotriene

Absorption

Clinical studies with radiolabeled ointment indicate that approximately 6% (+3%, SD) of the applied dose of calcipotriene is absorbed systemically when the ointment is applied topically to psoriasis plaques or 5% (+2.6%, SO) when applied to normal skin.

Toxicity

Topically applied calcipotriene can be absorbed in sufficient amounts to produce systemic effects. Elevated serum calcium has been observed with excessive use of calcipotriene.

Description

Calcipotriene also known as Calcipotriol, is a topical vitaminD3 derivative effective in the treatment of psoriasis vulgaris. The drug acts by binding to vitamin D3 receptors in the skin keratinocytes, producing an elevation in cell differentiation and a reduction in cell proliferation. Although its efficacy is comparable to calcitriol, calcipotriol exhibits at least 100 times less effect on calcium metabolism in rats.

Chemical properties

White Crystalline Solid

Originator

Leo Denmark (Denmark)

The Uses of Calcipotriene

Calcipotriene is an antipsoriatic that is a vitamin D3 analogue with low calcemic activity. It works by regulating the production and growth of skin cells. In the United States, this drug was first marketed under the trade name Dovonex and is used mainly for the treatment of psoriasis. It is one of the most effective non glucocorticoid topical drugs for the treatment of localized psoriasis.This drug has many off-label applications that are alternative therapies for many dermatologic diseases.

Indications

For the treatment of moderate plaque psoriasis in adults.

Background

Calcipotriol (INN) or calcipotriene (USAN) is a sythetic derivative of calcitriol or Vitamin D.

What are the applications of Application

Calcipotriol is vitamin D3 analog

Indications

Calcipotriene (Dovonex), a synthetic vitamin D3 derivative, is indicated for the treatment of moderate plaque psoriasis. Its mechanism of action is unknown, although it competes for calcitriol receptors on keratinocytes and normalizes differentiation. It also has a variety of immunomodulatory effects in the skin. Although the drug can cause local irritation, the most serious toxicities are hypercalciuria and hypercalcemia, which are usually reversible.

Definition

ChEBI: Calcipotriol is a seco-cholestane that is 26,27-cyclo-9,10-secocholesta-5,7,10,22-tetraene carrying additional hydroxy substituents at positions 1, 3 and 24. It is used (as its hydrate) in combination with betamethasone dipropionate, a corticosteroid, for the topical treatment of plaque psoriasis in adult patients. It has a role as a drug allergen and an antipsoriatic. It is a member of cyclopropanes, a secondary alcohol, a triol, a hydroxy seco-steroid and a seco-cholestane.

Preparation

A convergent approach for the total synthesis of calcipotriol (brand name: Dovonex), a proven Vitamin D analog used for the treatment of psoriasis, and medicinally relevant synthetic analogs is described.

A Synthesis of calcipotriol via a Key Electroreductive Cross-coupling Approach
Calcipotriol is currently the most successful VitD analog and is prescribed for the treatment of psoriasis, an autoimmune skin disease.

Manufacturing Process

(1S,3R)-Bis-(t-butyldimethylsilyloxy)-(20S)-formyl-9,10-secopregna(5E,7E,10 (19))triene (Calverley Tetrahedron 43.4609 (1967) and (cyclopropyl)(tri-phenylphoshoranylidene)ketone are stirred in dimethyl sulfoxide under nitrogen. The reaction mixture is then diluted at room temperature with ethyl acetate and washed with common salt solution. The organic phase is dried on sodium sulfate and filtered. After removal of the solvent, the residue is filtered with toluene through silica gel. Evaporation of the solvent and gradient chromatography (toluene/hexane (1:1)-toluene) of the residue on silica gel yield (5E,7E,22E),(1S,3R)-1,3-bis-(t-butyldimethylsilyloxy)-24-cyclopropyl- 9,10-secochola-5,7,10(19),22-tetraene-24-one.
(5E,7E,22E),(1S,3R)-1,3-Bis-(t-butyldimethylsilyloxy)-24-cyclopropyl-9,10- secochola-5,7,10(19),22-tetraene-24-one in tetrahydrofuran and methanol are mixed with a 0.4 M methanol CeCl3·7H2O solution. Sodium borohydride is added by portions under nitrogen with ice cooling. The suspension is stirred with ice cooling and then put into ice/common salt solution. The aqueous phase is extracted with ethyl acetate, the organic phase is washed neutral with water and dried on sodium sulfate. Filtration and removal of the solvent yield oil. By chromatography on silica gel with ethyl acetate/hexane (1:9). The (5E,7E,22E),(1S,3R,24S)-1,3-bis-(t-butyldimethylsilyloxy)-24-cyclopropyl- 9,10-secochola-5,7,10(19),22-tetraene-24-ol is obtained.
(5E,7E,22E),(1S,3R,24S)-1,3-Bis-(t-butyldimethylsilyloxy)-24-cyclopropyl- 9,10-secochola-5,7,10(19),22-tetraene-24-ol is dissolved in toluene and after addition of anthracene and 1 drop of triethylamine it is radiated at room temperature with a high pressure mercury vapor lamp (Heraeus TQ 150) through Pyrex glass. The reaction mixture is concentrated by evaporation and the residue a mixture of (5Z,7E,22E),(1S,3R,24S)-1,3-bis-(t-butyldimethylsilyloxy)-24-cyclopropyl-9,10-secochola-5,7,10(19),22-tetraene- 24-ol and anthracene - is directly reacted with tetrabutylammonium fluoride.
(5Z,7E,22E),(1S,3R,24S)-1,3-Bis-(t-butyldimethylsilyloxy)-24-cyclopropyl- 9,10-secochola-5,7,10(19),22-tetraene-24-ol in tetrahydrofuran is kept with a 1 M solution of tetrabutylammonium fluoride in tetrahydrofuran under nitrogen. For working up, the cooled reaction mixture is poured into cold sodium bicarbonate solution and then extracted with ethyl acetate. After drying of the organic phase on sodium sulfate, filtration and evaporation of the solvent yields a resin-like residue. Chromatography on silica gel with ethyl acetate/hexane (2:1) yields (5Z,7E,22E),(1S,3R,24S)-24-cyclopropyl-9,10- secochola-5,7,10(19),22-tetraene-1,3,24-triol.

brand name

Dovonex (Leo);Daivonex.

Therapeutic Function

Antipsoriatic

Biological Activity

Vitamin D 3 analog that displays minimal effects on calcium homeostasis. Regulates cell differentiation and proliferation; exhibits antiproliferative activity against human HL-60, HL60/MX2, MCF-7, T47D, SCC-25 and mouse WEHI-3 cancer cell lines.

Biochem/physiol Actions

Calcipotriol, a synthetic derivative of calcitriol or Vitamin D, is used in the treatment of psoriasis and marketed under the trade name Dovonex. It has comparable affinity with calcitriol (Vit. D) for the Vitamin D receptor (VDR), while being less than 1% as active as the calcitriol in regulating calcium metabolism. VDR belongs to the steroid/thyroid receptor superfamily, and is found on the cells of many different tissues including the thyroid, bone, kindney, and T cells of the immune system. Binding of calcipotriol to the VDR modulates the T cells gene transcription of cell differentiation and proliferation-related genes.

Pharmacokinetics

Calcipotriene is a synthetic analog of vitamin D. In humans, the natural supply of vitamin D depends mainly on exposure to the ultraviolet rays of the sun for conversion of 7-dehydrocholesterol to vitamin D3 (cholecalciferol) in the skin.

Pharmacology

Calcipotriene (Dovonex) enhances the effectiveness of ultraviolet B (UVB) but also increases photosensitivity in UVB-treated patients. Ultraviolet light, 6% salicylic acid, 12% lactic acid, hydrocortisone valerate 0.2% ointment, and tazarotene (Tazorac) gel degrade calcipotriene (Dovonex). Halobetasol ointment and 5% tar gel are compatible with Calcipotriene (Dovonex). A British study found calcipotriene (Dovonex) to be safe and effective in a pediatric population over the age of 3, although it is not approved by the FDA.

Side Effects

Possible side effects include:
severe burning, stinging, skin rash, or other irritation after applying the medicine;
worsening of your skin condition;
high calcium levels--confusion, tiredness, nausea, vomiting, loss of appetite, constipation, increased thirst or urination, weight loss;
mild skin irritation;
skin rash;
itching.

Metabolism

Hepatic. Calcipotriene metabolism following systemic uptake is rapid, and occurs via a similar pathway to the natural hormone. The primary metabolites are much less potent than the parent compound.

storage

Store at -20°C