Prostaglandin prodrugs. I: Stabilization of dinoprostone (prostaglandin E2) in solid state through formation of crystalline C1-phenyl esters.

Dinoprostone para-substituted phenyl esters were synthesized in attempt to improve the solid-state stability of the parent prostaglandin. A phenol series covering a wide melting-point range was employed, and a linear relationship was observed between the phenol melting points and the resulting prostaglandin C1-ester melting points. The crystalline esters showed improved solid-state stability over the parent compound, and many esters were biologically active.