Calcium phosphate porous pellets as drug delivery systems: Effect of drug carrier composition on drug loading and in vitro release

Drug loaded porous calcium phosphate bone substitutes are studied for targeted drug delivery applications. In this study, porous hydroxyapatite and beta-tricalcium phosphate pellets were investigated as anti-inflammatory drug carriers and their ibuprofen adsorption and release properties were compared. While the adsorption equilibrium time of 1 h was obtained for both pellets, hydroxyapatite pellets showed a higher adsorption capacity than beta-tricalcium phosphate. The physico-chemical characterisations of loaded pellets confirmed an ibuprofen reversible physisorption on both hydroxyapatite and beta-tricalcium phosphate pellets. Moreover, higher adsorption capacity of hydroxyapatite was attributed to their physical differences. The in vitro ibuprofen release evaluation showed 100% release of ibuprofen from both hydroxyapatite and beta-tricalcium phosphate pellets which was found to be compatible with the obtained interactions between the pellets and ibuprofen.