Gastro-intestinal tolerance following oral administration of spray-dried diclofenac-loaded nanocapsules and nanospheres

The aim of the study was to assess the potential of spray-dried polymeric nanocapsules or nanospheres to improve the gastro-intestinal tolerance of diclofenac after repeated intragastric administration. A preliminary pharmacokinetic study was conducted in order to ensure that the drug was absorbed from the spray-dried powders. Nanoparticle suspensions were prepared by polyester nanoprecipitation. Aerosil 200 was added to each suspension and the mixtures were fed into a spray-dryer. The gastro-intestinal tolerance study was carried out on male Wistar rats. Three consecutive oral doses (20 mg/kg/day) of diclofenac (salt, spray-dried salt, spray-dried free acid nanocapsules) dissolved or dispersed in water were administered. Diclofenac-loaded nanospheres and nanocapsule suspensions provided protection for all gastro-intestinal tissues. The spray-dried nanosphere redispersed powder exhibited a lack of protection following oral administration. Diclogenac-loaded spray-dried nanocapsules induced a protective effect on gastro-intestinal tissue.