The authors prepared and studied systems implantable in bone, for the slow release of an antineoplasic agent, @entity1499 ( @entity1500 ). The systems were made by compaction of a powdered mixture of an apatitic deficient @entity78 , dextran and various amounts of @entity1500 . Used as a matrix, this @entity78 has outstanding adsorption and compaction properties. It is an osteoconductor and biodegradable. The in vitro study carried out on these systems showed that the release of @entity1500 with time is slow and prolonged due to the phenomena of adsorption/desorption of @entity1500 onto deficient apatite. The composition of the implants changed with time towards that of stoichiometric apatite. The in vivo pilot study was performed by implantation in the external femoral condyle of @entity95 . A pharmacokinetic study revealed that the circulating concentration of @entity1500 in the blood was always below toxic levels. Twenty percent of the initial @entity1500 remained in the implants after 7 days. A study of the biocompatibility and bioreactivity showed no local @entity39 at any time, while implants degraded and new bone formed simultaneously. These implantable systems seem appear suitable for use immediately.

Study of implantable @entity78 systems for the slow release of XXXX .

@entity39 :: ('MESH:D009336', 'Disease') :: ['necrosis'] @entity78 :: ('MESH:C020243', 'Chemical') :: ['calcium phosphate'] @entity95 :: ('9986', 'Species') :: ['rabbits'] @entity1500 :: ('CHEBI:44185', 'Chemical') :: ['MTX'] @entity1499 :: ('MESH:D008727', 'Chemical') :: ['methotrexate']
@entity1499 :: (MESH:D008727,Chemical) :: ['methotrexate']
