Ss. Guterres et al., Gastro-intestinal tolerance following oral administration of spray-dried diclofenac-loaded nanocapsules and nanospheres, STP PHARM S, 11(3), 2001, pp. 229-233
The aim of the study was to assess the potential of spray-dried polymeric n
anocapsules or nanospheres to improve the gastro-intestinal tolerance of di
clofenac after repeated intragastric administration. A preliminary pharmaco
kinetic study was conducted in order to ensure that the drug was absorbed f
rom the spray-dried powders. Nanoparticle suspensions were prepared by poly
ester nanoprecipitation. Aerosil 200 was added to each suspension and the m
ixtures 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 nanocaps
ules) 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 spra
y-dried nanocapsules induced a protective effect on gastro-intestinal tissu
e.