Oil-in-water method for making alpha-2 agonist polymeric drug delivery systems

• US 7,589,057 B2
• Filed: 03/31/2006
• Issued: 09/15/2009
• Est. Priority Date: 04/30/2004
• Status: Active Grant

• Current Assignee: Allergan Incorporated (Abbvie Incorporated)
• Original Assignee: Allergan Incorporated (Abbvie Incorporated)
• Inventors: Chang, James, Hughes, Patrick
• Primary Examiner(s): Hartley; Michael G
• Assistant Examiner(s): SAMALA, JAGADISHWAR RAO
• Application Number:
  US11/395,019
• Publication Number:
  US 20060173060A1
• Time in Patent Office: 1,264 Days
• Field of Search: 424/426, 424/78.04, 514/392, 514/535, 514/536
• US Class Current: 514/1
• CPC Class Codes: A61K 31/4166 having oxo groups directly attached to the heterocyclic ring, e.g. phenytoin

Abstract

Biocompatible microparticles include an ophthalmically active alpha-2 adrenergic receptor agonist and a biodegradable polymer. The microparticles include oil-in-water emulsified microparticles which can be used to treat an ocular condition, such as glaucoma.

Claims

1. A method for making biodegradable polymeric microspheres for treating an ocular condition, the method comprising the steps of:

(a) combining a polylactic acid polyglycolic acid (PLGA) polymer with an alpha-2 adrenergic receptor agonist in an organic solvent to form a first oil phase;

(b) adding an excess amount of the alpha-2 adrenergic receptor agonist to water to form a saturated aqueous phase;

(c) emulsifying the first oil phase in the saturated aqueous phase by mixing the two phases together to form an oil in water emulsion; and

;

(d) removing the organic solvent from the oil phase of the oil in water emulsion using a second oil phase comprising a second organic solvent saturated with the alpha-2 adrenergic receptor agonist, thereby making biodegradable PLGA microspheres comprising the alpha-2 adrenergic receptor agonist, wherein the alpha-2 adrenergic agonist is brimonidine.

2. The method of claim 1, wherein the alpha-2 adrenergic receptor agonist of the microparticles so produced is encapsulated by the biodegradable polymer to preserve therapeutic activity of the alpha-2 adrenergic receptor agonist after a terminal sterilization procedure.