Novel vaginal delivery systems for calcitonin. II. Preparation and characterization of HYAFF® microspheres containing calcitonin

Microspheres prepared from hyaluronan esters (HYAFF®) have been evaluated as a novel delivery system for the vaginal administration of salmon calcitonin (sCT). HYAFF® microspheres containing sCT were prepared by a solvent extraction method. Spherical microspheres of about 10 mm in diameter with smooth surfaces were obtained. An HPLC method was developed for the determination of sCT incorporated into the microspheres. The efficiency of incorporation was high, with approximately 80 to 90% of the peptide recovered by extraction from the microspheres. Quantification of the extracted peptide in vivo confirmed that the biological activity of sCT was unaffected by the microsphere preparation process.