Latanoprost (free acid)-d₄(Lat-FA-d₄) contains four deuterium atoms at the 3, 3, 4, and 4 positions. It is intended for use as an internal standard for the quantification of Lat-FA by GC-or LC-mass spectrometry. Latanoprost is an F-series prostaglandin (PG) analog which has been approved for use as an ocular hypotensive drug.¹It is the isopropyl ester of a PGF_2αanalog containing an aromatic group (17-phenyl) in the ω-chain. As an isopropyl ester, latanoprost acts as a prodrug which is converted to Lat-FA by endogenous esterase enzymes. Lat-FA is a potent FP receptor agonist with an EC₅₀value of 3.6 nM for human FP receptors, which is twice the potency of PGF_2αand more than 200 times more potent latanoprost.²The efficacy of PG analog esters for the treatment of glaucoma correlates closely with the FP receptor binding affinity of the free acid.³However, Lat-FA is more irritating and less effective than the prodrug latanoprost when applied directly to the eyes of human glaucoma patients.⁴

1.Stjernschantz, J., and Resul, B.Phenyl substituted prostaglandin analogs for glaucoma treatmentDrugs of the Future17691-704(1992) 2.Abramovitz, M., Adam, M., Boie, Y., et al.The utilization of recombinant prostanoid receptors to determine the affinities and selectivities of prostaglandins and related analogsBiochim. Biophys. Acta1483(2)285-293(2000) 3.Camras, C.B., Alm, A., Watson, P., et al.Latanoprost, a prostaglandin analog, for glaucoma therapy. Efficacy and safety after 1 year of treatment in 198 patientsOphthalmology1031916-1924(1996) 4.Sugamoto, K., Matsushita, Y.i., and Matsui, T.Facile and general method for preparation of (E)-4-hydroxy-2-alkenalsLipids32903-905(1997)