Prostaglandin F2α isopropyl ester

PGF2α isopropyl ester is an ester prodrug of PGF2α with enhanced lipid solubility. Due to better membrane penetration, PGF2α isopropyl ester is more suitable than PGF2α or PGF2α tromethamine salt for topical application in studies on intraocular pressure. The ester functionality is readily hydrolyzed in vivo to release the active compound PGF2α. When administered topically to the eyes of cynomolgus monkeys, a 5 μg dose reduces intraocular pressure by 68% after the fourth day of treatment.

15(S)-15-methyl Prostaglandin F2α (15(S)-15-methyl PGF2α) has been shown to have potent uterine stimulant and abortifacient properties when administered intramuscularly to induce labor. 15(S)-15-methyl PGF2α isopropyl ester is a lipophilic analog of 15(S)-15-methyl PGF2α methyl ester, which may be hydrolyzed in vivo to the fully active free acid.

17-phenyl trinor PGF2α N-ethyl amide is an F-series prostaglandin analog which has been approved for use as an ocular hypotensive drug, sold under the Allergan trade name Bimatoprost. The N-ethyl amide prostaglandin prodrugs are converted to the active free acid more slowly than the analogous prostaglandin ester prodrugs such as latanoprost. This product is the isopropyl ester of the free acid prostaglandin which corresponds to Bimatoprost. The free acid, 17-phenyl trinor PGF2α, is a potent FP receptor agonist. In human and animal models of glaucoma, FP receptor agonist activity corresponds very closely with intraocular hypotensive activity. The 17-phenyl trinor PGF2α isopropyl ester derivative was examined for IOP-lowering activity during the development of latanoprost. At the dose of 3 μg eye in the monkey, 17-phenyl trinor PGF2α isopropyl ester was the most potent analog tested in reducing IOP, lowering the IOP 1.3 mm Hg below the level achieved by latanoprost. However, this derivative was also significantly more irritating to the eye than latanoprost.

Prostaglandin F2α (PGF2α) drives luteolysis and smooth muscle contraction by activating the FP receptor. Stable, lipophilic analogs of PGF2α are used to modulate luteolysis and treat glaucoma. 16-phenoxy tetranor Prostaglandin F2α isopropyl ester (16-phenoxy tetranor PGF2α isopropyl ester) is a lipophilic analog of 16-phenoxy tetranor PGF2α. Isopropyl esters of PGs serve as prodrugs, as they are efficiently hydrolyzed in certain tissues to generate the bioactive free acid.

Latanoprost, the isopropyl ester of 17-phenyl-13,14-dihydro prostaglandin F2α, serves as a prodrug for the free acid form, a potent FP receptor agonist in the eye. Isopropyl 5-(diphenylphosphoryl)pentanoate may exist as a potential trace impurity in commercial latanoprost preparations.

Cloprostenol isopropyl ester is a PGF2α agonist and a similar synthetic prostaglandin F2α (PGF2α), which can induce luteal dissolution in mares during the luteal phase without causing clinical side effects or stress responses.

A number of 17-phenyl trinor prostaglandin F2α (17-phenyl trinor PGF2α) derivatives have been approved for the treatment of glaucoma. Of these, the unsubstituted or meta-substituted aromatic derivatives are the most potent FP receptor agonists. 17-trifluoromethylphenyl trinor PGF2α bears an aromatic ring which is reminiscent of the trifluoromethyl-phenoxy ring of travoprost ((+)-fluprostenol isopropyl ester). As an ocular hypotensive agent, it would be expected that 17-trifluoromethylphenyl trinor PGF2α would act very much like the free acid of travoprost. 17-phenyl trinor PGF2α is a potent luteolytic and abortifacient, with a potency equal to or greater than fluprostenol and cloprostenol.

15(S)-Fluprostenol isopropyl ester, an isomer of the prostaglandin F2α analog, fluprostenol isopropyl ester, serves as a possible prodrug to 15(S)-fluprostenol. It has the potential to act as an agonist at FP receptors, albeit with lower potency compared to the 15(R) epimer and the FP receptor agonist, fluprostenol. Additionally, it may be present as a potential impurity in commercial formulations of fluprostenol isopropyl ester.

A number of 17-phenyl trinor prostaglandin F2α(17-phenyl trinor PGF2α) derivatives have been approved for the treatment of glaucoma.1,2,3Of these, the ones wherein the 13,14-double bond has been hydrogenated retain relatively good potency, but show a significantly reduced incidence of local irritant side effects.417-trifluoromethylphenyl-13,14-dihydro trinor PGF2αbears an aromatic ring which is reminiscent of the trifluoromethyl-phenoxy ring of travoprost ((+)-fluprostenol isopropyl ester). As an ocular hypotensive agent, it would be expected that 17-trifluoromethylphenyl-13,14-dihydro trinor PGF2αwould act very much like the free acid of latanoprost.