TY - JOUR
T1 - Characterisation and controlled drug release from novel drug-loaded hydrogels
AU - Geever, Luke M.
AU - Cooney, Ciaran C.
AU - Lyons, John G.
AU - Kennedy, James E.
AU - Nugent, Michael J.D.
AU - Devery, Sinead
AU - Higginbotham, Clement L.
PY - 2008/8
Y1 - 2008/8
N2 - Hydrogel based devices belong to the group of swelling controlled drug delivery systems. Temperature responsive poly(N-isopropylacrylamide)-poly(vinylpyrrolidinone) random copolymers were produced by free radical polymerisation, using 1-hydroxycyclohexylphenyketone as an ultraviolet-light sensitive initiator, and poly(ethylene glycol) dimethacrylate as the crosslinking agent (where appropriate). The hydrogels were synthesised to have lower critical solution temperatures (LCST) near body temperature, which is favourable particularly for 'smart' drug delivery applications. Two model drugs (diclofenac sodium and procaine HCl) were entrapped within these xerogels, by incorporating the active agents prior to photopolymerisation. The properties of the placebo samples were contrasted with the drug-loaded copolymers at low levels of drug integration. Modulated differential scanning calorimetry (MDSC), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and atomic force microscopy (AFM) were used to investigate the influence of the drugs incorporated on the solid-state properties of the xerogels. MDSC and swelling studies were carried out to ascertain their effects on the LCST and swelling behaviour of the hydrated samples. In all cases, drug dissolution analysis showed that the active agent was released at a slower rate at temperatures above the phase transition temperature. Finally, preliminary in vitro cytotoxicity evaluations were performed to establish the toxicological pattern of the gels.
AB - Hydrogel based devices belong to the group of swelling controlled drug delivery systems. Temperature responsive poly(N-isopropylacrylamide)-poly(vinylpyrrolidinone) random copolymers were produced by free radical polymerisation, using 1-hydroxycyclohexylphenyketone as an ultraviolet-light sensitive initiator, and poly(ethylene glycol) dimethacrylate as the crosslinking agent (where appropriate). The hydrogels were synthesised to have lower critical solution temperatures (LCST) near body temperature, which is favourable particularly for 'smart' drug delivery applications. Two model drugs (diclofenac sodium and procaine HCl) were entrapped within these xerogels, by incorporating the active agents prior to photopolymerisation. The properties of the placebo samples were contrasted with the drug-loaded copolymers at low levels of drug integration. Modulated differential scanning calorimetry (MDSC), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and atomic force microscopy (AFM) were used to investigate the influence of the drugs incorporated on the solid-state properties of the xerogels. MDSC and swelling studies were carried out to ascertain their effects on the LCST and swelling behaviour of the hydrated samples. In all cases, drug dissolution analysis showed that the active agent was released at a slower rate at temperatures above the phase transition temperature. Finally, preliminary in vitro cytotoxicity evaluations were performed to establish the toxicological pattern of the gels.
KW - Drug delivery
KW - Hydrogels
KW - Lower critical solution temperature
KW - Photopolymerisation
KW - Temperature sensitive
UR - http://www.scopus.com/inward/record.url?scp=48349112623&partnerID=8YFLogxK
U2 - 10.1016/j.ejpb.2007.12.021
DO - 10.1016/j.ejpb.2007.12.021
M3 - Article
C2 - 18502627
AN - SCOPUS:48349112623
SN - 0939-6411
VL - 69
SP - 1147
EP - 1159
JO - European Journal of Pharmaceutics and Biopharmaceutics
JF - European Journal of Pharmaceutics and Biopharmaceutics
IS - 3
ER -