A study on partially biodegradable microparticles as carriers of active glycolipids.

This paper describes a study on the preparation and characterisation of partially biodegradable microparticles of poly(epsilon-caprolactone)/poly(ethyl methacrylate) (PCL/PEMA) as carriers of synthetic glycolipids with antimitotic activity against brain tumour cells. Microparticles prepared by suspension polymerisation of methacrylate in the presence of already polymerised PCL showed a predominantly spherical but complex morphology, with segregation of PCL micro/nano-domains towards the surface. Small diameter discs were prepared by compression moulding of blends of microparticles and the active principle under mild conditions. The in vitro behaviour of the discs and release of the glycolipid were studied in different simulated fluid models. Ingress of fluids increased with increasing hydrophobicity of the medium. Release of the glycolipid was sustained in all fluids, the most prolonged profile being in human synovial fluid and phosphate-buffered saline modified with 20 vol.% dioxane. Slow disintegration of the discs and partial degradation of the microparticles was evident in accelerated studies. The antimitotic activity of glycolipid released from the discs was proved against a human glioblastoma line. This activity, along with selectivity against human fibroblasts, could be controlled by the amount of drug charged in the disc.