Microencapsulation of apomorphine HCI with gelatin

Abstract

Microspheres of apomorphine HCI were prepared, with gelatin as polymer coating material, using the emulsification solvent extraction method. The microencapsulation efficiency, particle size and release profile were compared to those of riboflavin sodium phosphate (RSPh). An efficiency of approximately 95% was obtained with RSPh while the quantity of acetone and ether used as preparative solvents resulted in low microencapsulation efficiency for apomorphine HCI. A reduction of the volumes of these solvents improved the efficiency by a factor of more than two but the mean particle size range became slightly higher due to agglomeration as compared to the mean particle size when more solvent was used. A faster release rate was found for RSPh than for apomorphine HCI, according their water solubilities. Crosslinking of gelatin-RSPh microspheres with formaldehyde and glutharaldehyde (10 and 20% v/v for 1, 6, and 24 h) did not extend the duration of release of RSPh and reduced the quantity of drug microencapsulated.