Ionically cross-linked alginate hydrogels as drug delivery systems for analgesics in broiler chickens : thesis presented in partial fulfilment of the requirement for the degree of Masters of Science in Chemistry at Massey University, Palmerston North, Manawatu, New Zealand
Loading...
Date
2017
DOI
Open Access Location
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Massey University
Rights
The Author
Abstract
Treating birds with analgesic drugs requires continuous injections of near lethal
concentrations to maintain the therapeutic dose in the blood plasma. This is due to birds
having higher metabolic rates than mammals. Therefore, there is a need to develop drug
delivery systems that can control and slow down the release of analgesics in birds. This
study was designed to analyse the sustained release of the model analgesics, sodium
salicylate and sodium aspirin, from ionically cross-linked alginate hydrogels, in in vitro
and in vivo experiments using broiler chickens as the model bird. Analgesic loaded
hydrogels separated into two layers, unlike the homogeneous blank hydrogels. This was
labelled as the separation effect. Swelling studies indicated the absence of the insoluble
cross-linked alginate material in the hydrogels where the separation effect occurred,
with most of the hydrogels dissolving back into the medium. The highest equilibrium
swelling percentage achieved in the loaded hydrogels was 68 %. In comparison, the
highest equilibrium swelling percentage in the blank hydrogels was 622 %. In vitro drug
release profiles showed that the hydrogels released up to 100% of the sodium salicylate
within 3.33 hours. In contrast, the hydrogels containing sodium aspirin released only 35
% of the encapsulated drug. Hydrogels containing a drug concentration of 150 mg/mL
were injected into the model birds at a dose rate of 150 mg/Kg. No chicken reacted
negatively to the hydrogel injection. In vivo results indicate sustained release of the
model analgesic from the hydrogels compared to the release from the aqueous solutions
of the drug. The effective concentration for an analgesic effect of sodium salicylate was
maintained by the group injected with an aqueous solution of sodium salicylate 18 hours
after the injection. The groups injected with the hydrogel with the maximum calcium
chloride content saw the largest sustained release, with the plasma concentration of
sodium salicylate remaining over the effective concentration for up to 36 hours after the
injection.
Keywords: Sodium salicylate, sodium aspirin, hydrogel, analgesia, sustained release,
broiler chicken.
Description
Keywords
Colloids, Alginates, Analgesics, Controlled release, Drug delivery systems, Broilers (Poultry), Research Subject Categories::TECHNOLOGY::Chemical engineering::Other chemical engineering, Sodium salicylate, Sodium aspirin, Sustained release, Broiler chicken