Abstract: The present invention provides an improved method for treatment of diseased tissue, which comprises the steps of:(i) selecting at least a magnetic material which has a magnetic heating efficiency of at least about 4.5.times.10.sup.-8 J.m./A.g, when rotational magnetic field conditions are equal to or less than about 5.times.10.sup.8 A/m.s;(ii) delivering the magnetic material to a patient's diseased tissue; and(iii) exposing the magnetic material to a rotational magnetic field with a frequency of greater than about 10 kHz and a field strength selected such that the product of field strength, frequency and the radius of the exposed region is less than about 7.5.times.10.sup.7 A/s to generate hysteresis heat in the diseased tissue.

Abstract: A controlled release preparation comprises an ionic polymer matrix loaded with an active compound, particularly a pharmaceutically active compound such as doxorubicin or other cytotoxic or cytostatic drug, the active compound being complexed with a complexing agent such as a metal ion to modify the release of the active compound from the polymer matrix. The ionic polymer matrix may be provided in the form of microspheres, such as microspheres of crosslinked albumin/dextran sulphate.