WARNER-LAMBERT/ALZA TO DEVELOP NEW SUSTAINED-RELEASE DILANTIN FORMULATION

Warner-Lambert has contracted Alza to assist in development of a sustained-release version of Dilantin (phenytoin), Warner- Lambert Chairman Melvin Goodes told securities analysts April 21. The currently marketed once-daily Dilantin Kapseals were the subject of a meeting of FDA's Generic Drugs Advisory Committee Feb. 13, after which Warner-Lambert announced that Dilantin Kapseals would not be reformulated ("The Pink Sheet" Feb. 22, 1993, T&G-11). FDA was concerned with lot-to-lot variability of Dilantin, particularly in light of quality control problems in Puerto Rico, where the product is manufactured. Development of a new dosage form of Dilantin could result in further exclusivity for the off-patent drug. No generic sustained- release phenytoin products have been marketed since Bolar's was taken off the market in 1990. During the open portion of its Feb. 13 meeting, the Generic Drugs Advisory Committee agreed that a confidence interval for phenytoin bioavailability of plus or minus 20% is too broad and suggested a range of plus or minus 5% might be more appropriate -- a decision that would appear to further hamper attempts to gain ANDA approval for extended-release phenytoin ("The Pink Sheet" Feb. 15, 1993, p. 16). Of Warner-Lambert's sustained-release gemfibrozil product, de Vink said, "We were obviously disappointed in our efforts to get Lopid SR on the market" before immediate-release Lopid lost its patent protection on Jan. 4, "but at the same time, we are working with Alza to develop an entirely new approach to a sustained- release Lopid." Alza is using its push-pill release system for the product ("The Pink Sheet" May 11, 1992, In Brief). Alza is also developing a sustained-release version of Cognex (tacrine). Warner-Lambert said in February that it expects Lopid SR to gain approval most likely for the lowering of triglyceride levels, but not for treatment of coronary heart disease. Asked by an analyst how the two extended-release gemfibrozil products fit into Warner-Lambert's plans, Pharmaceutical Sector President Joseph Smith indicated that both will be marketed. He said Lopid SR, for which the company hopes to gain approval by next year, would be "an intermediate step" and the Alza formulation is "more of a long-term play."