Pharmaceutical preparations; biological preparations for medical and veterinary purposes; capsules and particles for medical and pharmaceutical purposes; chemical preparations for medical and pharmaceutical purposes; chemical preparations for veterinary purposes; drugs for medical purposes; microcapsules; microscopic particles containing chemicals; microcapsules containing pharmaceutical, veterinary or medical preparations; microcapsules and microparticles adapted to selectively deliver chemical agents to a target; microscopic particles and microcapsules for the treatment of cancer; microscopic particles adapted to selectively deliver chemicals to a target site such as a cell or organ