Synthesis of poly(p-dioxanone) catalyzed by Zn L-lactate under microwave irradiation and its application in ibuprofen delivery.

Microwave-assisted ring-opening polymerization (ROP) of p-dioxanone (PDO) catalyzed by Zn L-lactate (Znlac(2)) was investigated and the purified product was characterized by (1)H-NMR. When the ROP of PDO was carried out at 100 degrees C for 6.5 h, the viscosity-average molecular weight (M(v)) of poly(p-dioxanone) (PPDO) reached 53.2 kg/mol. The kinetics of ring-opening polymerization of PDO under microwave irradiation were investigated and the polymerization reaction was accurately first-order with respect to monomer concentration. The reaction rate was greatly accelerated by microwave irradiation, compared with conventional heating. The resultant PPDO was used as carrier and drug-release systems were prepared using ibuprofen (IBU) as model drug with 10, 15 and 20% loading. The release behavior of the systems was investigated in phosphate buffer solution at 37 degrees C and the release of IBU from the system was sustained and steady. The resultant PPDO could be well used as the carrier for the delivery drug.