Progesterone-loaded chitosan microspheres: a long acting biodegradable controlled delivery system

Smooth, highly spherical, crosslinked chitosan microspheres in the size range of 45–300 μm loaded with progesterone were prepared by glutaraldehyde crosslinking of an aqueous acetic acid dispersion of chitosan containing progesterone in a non-aqueous dispersion medium consisting of liquid paraffin and petroleum ether stabilized using sorbitan sesquioleate. In vitro release of the drug into phosphate buffer at 37°C was determined as a function of...