What filler materials are used in the drug revia or depade (naltrexone)?

Revia (naltrexone) Ingredients: Active: Naltrexone. Inactive Ingredients SILICON DIOXIDE CROSPOVIDONE HYPROMELLOSE 2910 (3 MPA.S) HYPROMELLOSE 2910 (6 MPA.S) LACTOSE MONOHYDRATE MAGNESIUM STEARATE CELLULOSE, MICROCRYSTALLINE POLYETHYLENE GLYCOL 400 POLYSORBATE 80 FERRIC OXIDE RED FERRIC OXIDE YELLOW TITANIUM DIOXIDE.