Methotrexate polymer implant for the treatment of head and neck cancer

A biodegradable polymeric device releasing methotrexate (MTX) for the treatment of cancer of the head and neck was evaluated in vitro and in vivo. The polymer used for the preparation of the device was a copolyanhydride based on dimer erucic acid and sebacic acid loaded with 2–20% MTX. The drug was released constantly for about two weeks from small discs (1 × 3 mm) with complete degradation of the polymer when placed in phosphate buffer pH 7.4 at 37°C. The release and degradation rate was similar for all drug loading. MTX-loaded discs implanted subcutaneously in mice released the drug for about ten days with about 50% elimination of the device from the implantation site. The drug concentration was the highest in the tissue in contact with the device and decreased at distance from the device following a first order kinetics. The LD50 of MTX in polymer when implanted in mice was between 20 and 40 mg per kg. (1994)