Benzonatate Patent with Composition of Matter Claim
Benzonatate is a mixture of butyl 4-aminobenzoate compounds
This patent provides compositions of the resinate-bound benzonatate that minimizes release in the oral cavity.
This patent also shows that the composition of benzonatate for the ion exchange resin releases in the same proportion as the existing benzonatate composition.
Only cationic ion exchange resin in acid form having weak acid functionality work for this