Degradation and drug release characteristics of monosize polyethylcyanoacrylate microspheres.

Monosize, biodegradable poly(ethylcyanoacrylate) (PECA) microspheres with a diameter of 1.3 microns were prepared by a relatively new polymerization method, the so-called phase inversion polymerization. The effects of pH and temperature on the degradation behavior of PECA particles were investigated. PECA microspheres were degraded mainly by surface erosion. The degradation rate increased with increasing pH temperature. A model drug, i.e. 2,4-dinitrophenylhydrazine (DNPH) was loaded into the monosize PECA microspheres during polymerization. The drug incorporation into the PECA microspheres increased with increasing initial drug concentration in the monomer phase. Drug release from the PECA microspheres was investigated at different pH. Higher drug release rates were observed in the neutral and alkaline media as compared with the acidic medium.