Latanoprost (free acid) (L-arginine salt)

Latanoprost (free acid) (L-arginine salt) is a salt form of latanoprost (free acid) that results in a crystalline solid. This solid form of latanoprost improves ease of handling, making it ideal for use as a synthetic intermediate and for compounding it into mixtures with other components. Latanoprost (free acid) is a derivative of prostaglandin F2α , an FP receptor agonist, and an active metabolite of the prodrug latanoprost . It selectively binds to the FP receptor (Ki = 0.098 µM) over the EP1, EP1, EP3, and EP4 receptors (Kis = 2.06, 39.667, 7.519, and 75 µM, respectively), as well as the DP, IP, and TP receptors (Kis = ≥20, ≥90, and ≥60 µM, respectively). It induces phosphoinositide turnover in isolated human ciliary muscle and human trabecular meshwork cells, mouse NIH3T3 fibroblasts, and rat A7r5 vascular smooth muscle cells, which all endogenously express FP receptors (EC50s = 124, 35, 32, and 35 nM, respectively), as well as HEK293 cells expressing human ocular FP receptors (EC50 = 45.7 nM). It also increases intracellular calcium levels in hEP1-5/293-AEQ17 cells expressing EP1 receptors in an aequorin-based calcium assay (EC50 = 119 nM). Latanoprost (free acid) induces contraction of isolated cat iris sphincter smooth muscle (EC50 = 29.9 nM).