Polymeric nanoparticles as an oral delivery system for biocontrol agents for the brushtail possum (Trichosurus vulpecula).
OBJECTIVE
To investigate polymeric nanoparticles as an oral delivery system for protein biocontrol agents for control of the brushtail possum, Trichosurus vulpecula.


METHODS
Insulin-loaded poly(ethyl 2-cyanoacrylate) (PECA) nanoparticles were prepared using interfacial polymerisation, and characterised for size, zeta potential, and efficiency of encapsulation of insulin. In-vitro release of insulin-loaded PECA nanoparticles was quantified using reverse-phase high-pressure liquid chromatography (HPLC). The in-vivo pharmacokinetics of insulin in PECA nanoparticles was investigated following I/V administration, and when injected directly into the caecum alone or in conjunction with the permeation enhancer EDTA. Blood samples were collected at intervals from -5 to 180 minutes, and the concentration of insulin in plasma was quantified using a radioimmunoassay (RIA) validated for possum plasma.


RESULTS
Poly(ethyl 2-cyanoacrylate) nanoparticles were produced with a uniform particle size of 200-300 nm, and the mean entrapment of insulin was 78%. In-vitro release of insulin from the PECA nanoparticles was controlled, although incomplete, and approximately 30% of the insulin remained entrapped. The bioavailability of insulin when administered in a PECA nanoparticulate formulation injected directly into the caecum was <1%, and was not increased by addition of the permeation enhancer.


CONCLUSIONS
The nanoparticulate formulations investigated as part of this study resulted in low bioavailability of the peptide insulin in the brushtail possum.
McDowell
A
A
School of Pharmacy, University of Otago, PO Box 56, Dunedin 9054, New Zealand. arlene.mcdowell@otago.ac.nz
McLeod
B J
BJ
Rades
T
T
Tucker
I G
IG
D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D002432:Cecum; D056148:Chromatography, Reverse-Phase / Q000662:veterinary; D003487:Cyanoacrylates; D016503:Drug Delivery Systems / Q000379:methods / Q000662:veterinary*; D007275:Injections, Intravenous; D007328:Insulin / Q000097:blood* / Q000493:pharmacokinetics*; D053758:Nanoparticles / Q000008:administration & dosage*; D009520:New Zealand; D010572:Pest Control, Biological / Q000379:methods*; D011863:Radioimmunoassay / Q000662:veterinary; D048330:Trichosurus / Q000378:metabolism*
D003487:Cyanoacrylates; D007328:Insulin; C029054:ethyl 2-cyanoacrylate