INVESTIGATION INTO THE YELLOWING ON AGING OF SABRIL@ TABLET CORES

AbstractUncoated Sabril® tablet cores under long term storage become slightly discolored from the initial white to a yellowish off-white color. In order to ensure the aesthetics of the product, Sabril tablet cores are film coated with an opaque white coating. The nature of this yellowing reaction was of interest even though discolored tablets showed no significant loss of potency on assay. Excipient compatibility studies showed that the vigabatrin active in Sabril mixed with Avicel (microcrystalline cellulose) in the presence of moisture also became off-colored when stressed at elevated temperatures.The nature of the discoloration in aged Sabril core tablets was investigated. Chromatographic and spectroscopic data indicate that the source of this color comes from the Maillard Reaction between vigabatrin and Avicel which results in a multitude of products analogous to “browning reactions” of food products. A gravimetric determination of the leached colored products from 7 year old Sabril core tablets gave ...