The present invention provides a novel process for preparation of the
tannate salt of gabapentin for human and veterinary pharmaceutical use.
Tannate salts of active pharmaceutical ingredients are used in sustained
release applications and to improve certain organoleptic properties such
as taste. However, the prior art neither discloses nor suggests the
preparation of gabapentin tannate. The process for preparing gabapentin
tannate includes the mixing of gabapentin and tannic acid together in the
presence of one or more solvents. The method may further include the step
of selecting the one or more solvents from a group consisting of purified
water, ethanol, glycerin, propylene glycol, diethylether, methylene
chloride, acetone, isopropyl alcohol and mixtures thereof. The process
may also include the steps of isolating and purifying the tannate salt.
This may be accomplished by filtration, drying, centrifugation and
lyophilization. The process may utilize either natural or synthetic
tannic acid.