Reaction #1483116

Reaction equation

Oxytocin acetate

→

Oxytocin

Yield 71.5%

Solvents

EtOAc

MeOH

EtOAc

Conditions

Workup

1. 1
   workup.ADDITIONadded to the polymer solution
2. 2
   Otheryielding a milky suspension as the organic phase
3. 3
   Otherto provide an emulsion
4. 4
   OtherThe emulsion was collected directly into a 10 mM sodium phosphate (pH 8, 0° C., 150 mL) solvent extraction solution
5. 5
   Extractionto extract EtOAc
6. 6
   FiltrationHardened microparticles were collected by filtration
7. 7
   Washwashed with water, air
8. 8
   Otherdried
9. 9
   Otherstored at 4° C

Procedure

PLGA polymer (MW 13,000, 180 mg) was dissolved in EtOAc (900 μL). Oxytocin acetate (20 mg) was dissolved in MeOH (100 μL) and added to the polymer solution yielding a milky suspension as the organic phase. The resulting organic phase was combined with a 1% PVA aqueous phase containing 5% EtOAc to provide an emulsion. The emulsion was collected directly into a 10 mM sodium phosphate (pH 8, 0° C., 150 mL) solvent extraction solution and stirred for four hours while warming to room temperature to extract EtOAc. Hardened microparticles were collected by filtration, washed with water, air dried and stored at 4° C. This provided formulation BL (143 mg, 71.5% yield) with a median particle size 44.0 μm. The core load (1.67%), encapsulation efficiency (16.7%) and in vitro burst (46.3%) were determined by RP-HPLC assay.

Source