SUSTAINED-RELEASE FLUORIDE DENTIFRICE

THE OVERALL OBJECTIVE OF THE 6-MONTH PROJECT IS TO DEVELOP ASUSTAINED-RELEASE FLUORIDE DENTIFRICE FORMULATION BASED ON MICROCAPSULES WITH A DURATION OF 12 TO 24 HOURS. IN PHASE I, SODIUM FLUORIDE MICROCAPSULES WILL BE PREPARED AND CHARACTERIZED FOR NAF CONTENT, GEOMETRY, AND FLUORIDE-RELEASE PROFILE. A GLYCERIN-BASED FORMULATION WILLBE DEVELOPED FOR SUSPENDING THE MICROCAPSULES, AND THE STABILITY OF THE FLUORIDE MICROCAPSULES IN THE FORMULATION WILL BE DETERMINED. THESE STUDIES WILL FORM THE BASIS FOR MORE EXTENSIVE PRECLINICAL TESTING OF THE FORMULATION IN VITRO AND IN ANIMALS, WHICH IS PLANNED FOR PHASE II. THE GOALS OF PHASE III ARE TO SECURE AN INVESTIGATIONAL NEW DRUG (IND) APPROVALAND PROCEED WITH CLINICAL TRIALS OF THE DENTIFRICE IN COLLABORATION WITH A COMMERCIAL ORGANIZATION. THE PRINCIPAL INVESTIGATOR WAS INVOLVED IN TWO PREVIOUS STUDIES OF MICROENCAPSULATED SODIUM FLUORIDE SPONSORED BY NIDR. SODIUM FLUORIDE MICROCAPSULES, 38 TO 300 MICRONS, WERE RECENTLY PREPARED AT BIOTEK, INC. USING A FLUIDIZED-BEDPROCESS. PRELIMINARY STUDIES SHOW FLUORIDE RELEASE TO BE RELATED TO CAPSULE GEOMETRY, THUS CONFIRMING THE PREDICTIONSOF RELEASE THEORY. STUDIES OF FLUORIDE RELEASE IN GLYCERIN/WATER MIXTURES SHOW THAT GLYCERIN WOULD BE AN EXCELENT CANDIDATE FOR SUSPENDING AND STORING NAF MICROCAPSULES WITHOUT LEACHING FLUORIDE FROMTHE CAPSULES. THE FINAL PRODUCT WILL BE A MULTICOMPONENT TOOTHPASTE IN WHICH THE GLYCERIN MICROCAPSULE SUSPENSION IS STORED IN PARALLEL WITH A WATER-BASED PASTE. THE TWO WILL BE MIXED IMMEDIATELY BEFORE USE WHEN THE TUBE IS SQUEEZED TODELIVER THE TWO PASTES TO THE TOOTHBRUSH.