An effective prodrug strategy to selectively enhance ocular exposure of a cannabinoid receptor (CB1/2) agonist

J Med Chem. 2013 Jul 11;56(13):5464-72. doi: 10.1021/jm4004939. Epub 2013 Jun 19.

Abstract

Glaucoma is a leading cause of vision loss and blindness, with increased intraocular pressure (IOP) a prominent risk factor. IOP can be efficaciously reduced by administration of topical agents. However, the repertoire of approved IOP-lowering drug classes is limited, and effective new alternatives are needed. Agonism of the cannabinoid receptors CB1/2 significantly reduces IOP clinically and experimentally. However, development of CB1/2 agonists has been complicated by the need to avoid cardiovascular and psychotropic side effects. 1 is a potent CB1/2 agonist that is highly excluded from the brain. In a phase I study, compound 1 eyedrops were well tolerated and generated an IOP-lowering trend but were limited in dose and exposure due to poor solubility and ocular absorption. Here we present an innovative strategy to rapidly identify compound 1 prodrugs that are efficiently metabolized to the parent compound for improved solubility and ocular permeability while maintaining low systemic exposures.

MeSH terms

  • Animals
  • Area Under Curve
  • Eye / metabolism
  • Eye / physiopathology
  • Glaucoma / metabolism
  • Glaucoma / physiopathology
  • Glaucoma / prevention & control
  • Humans
  • Intraocular Pressure / drug effects
  • Male
  • Metabolic Clearance Rate
  • Models, Chemical
  • Molecular Structure
  • Ophthalmic Solutions / chemical synthesis
  • Ophthalmic Solutions / pharmacokinetics
  • Ophthalmic Solutions / pharmacology*
  • Permeability
  • Prodrugs / chemical synthesis
  • Prodrugs / pharmacokinetics
  • Prodrugs / pharmacology*
  • Rats
  • Receptor, Cannabinoid, CB1 / agonists*
  • Receptor, Cannabinoid, CB1 / metabolism
  • Receptor, Cannabinoid, CB2 / agonists*
  • Receptor, Cannabinoid, CB2 / metabolism

Substances

  • Ophthalmic Solutions
  • Prodrugs
  • Receptor, Cannabinoid, CB1
  • Receptor, Cannabinoid, CB2