Study On Naproxen Sodium Sustained Release Pellets

Naproxen sodium is a nonsteroidal anti-inflammatory drug for mild and moderate pain relief,and is also applies to rheumatoid arthritis, acute gouty arthritis etc. In order to get a quick and long-term effect,thus to reduce frequency of administration and fluctuations in blood concentration., the combined pellets of immediate-sustained release of NPS are prepared.NPS immediated-release pellets are prepared by extrusion-spheronization, with MCC as diluent agent. Take yield, roundness, Friability, particle size distribution as indexs to evaluate the quality of immediate-release pellets, the NPS pellets present high yield, perfect sphericity and friability,the accumulative release of NPS in 10 min was above 90%.A fluid-bed spray processor is adopted for pellets coating with surelease(?) as coating film, HPMC as porogenic agent. The effect of coating level, the kind and amount of porogenic agent, the concentration of surelease(?), curing time on the release of NPS from the pellets is studied with the accumulative release percentages as indexs. The optimal formulation is obtained by central composite design. Linear regression equation and predicted response surface and contour plot are given by SAS soft ware.NPS pellets are combined with immediate-release pellets and sustained pellets in 2:1 rate. The result of in vitro release indicate that the combined pellets can rapidly release at first, after that perform a sustained release.The plasma concentration in six beagle dogs are determined by HPLC after single oral administration of commercial and test formulation. The pharmacokinetics parameters are AUC0-t 1258.33±151.74μg·h/mL and 1218.94±179.86μg·h/mL, cmax 68.04±9.65μg/mL and 152.38±16.61μg/mL, tmax 1.67±0.29 h and 0.92±0.14 h, respectively. The relative bioavailability of NPS immediate-sustained release pellets was 104.4±14.5%。...