Magnetic microsphere use for drug targeting.</li></li></ul><li>4<br />
MAGNETIC MICROSPHERE<br /><ul><li>Magnetic microspheres are supramolecular particles that are small enough to circulate through capillaries without producing embolic occlusion but are (ferromagnetic) to be captured in micro vessels.
dragged in to the adjacent tissues by magnetic fields of 0.5-0.8 tesla (T) </li></li></ul><li>CONCEPT<br /><ul><li>The use of magnetic force for site-specific drug delivery by using albumin microspheres containing magnetite appears to be a promising strategy.
Significant improvements in response can be incorporated and obtained with magnetic albumin microspheres delivery system compared with conventional and nonmagnetic microspheres drug regimens.</li></li></ul><li>HISTORY OF MAGNETIC GUIDANCE<br /><ul><li>Tyle 1988
Earliest use of magnet for selective delivery of clinical agents involved treatment of arterial thrombosis by use of carbonyl iron.</li></li></ul><li>
MAGNETITE<br /><ul><li>Magnetite a ferromagnetic materials when incorporated in to microspheres makes them magnetically responsive so that they can be concentrated to the desired site by applying </li></ul>some magnetic field.<br /><ul><li>Fe3O4</li></li></ul><li>
Alternating magnetic field<br />Ferromagnetic<br />microspheres<br />(20-30 mm)<br />Microsphere<br />Artery<br />Catheter<br />Tumor<br />Alternating magnetic field<br />12<br />
PREPARATION<br />There is mainly 2 method of microsphere preparation.<br />Phase separation emulsion polymerisation.<br />Continuous solvent evaporation.<br />
PHASE SEPARATION EMULSION POLYMERISATION <br />ALBUMIN+DRUG+MAGNETITE+VEGETABLE OIL<br /> SOLUTION<br />HEAT<br />SUSPENSION SEPARATED FROM OIL STORE AT 40C<br />
CONTINUOUS SOLVENT EVAPORATION<br />VOLATILE ORGANIC SOLVENT+POLYMER+DRUG+MAGNETITE<br />STIRRING<br />CENTRIFUGED AND MICROSPHERE SEPARATED AND STORED<br />
Improvement in drug release.</li></li></ul><li>
REFERENCES<br />Y.W. Chien, Concepts and system design for the rate-controlled drug delivery, Drug and pharmaceutical sciences, Marcel Dekker Inc. York, 2nd Edn. 50 (1992): pp. 1-139.<br />S.P. Vyas & R.K. Khar, Targeted and Controlled Drug Delivery.1st edn, CBS publisher & distributor New Delhi.<br />H.A. Lieberman, M.R. Martin & G.S. Banker, Pharmaceutical dosage forms: Disperse Systems vol-2.<br />American journal of pharmaceutical sciences.<br />www.dogpile.com<br />www.pubmed.com<br />