Precautionary note for use of bisulfite in pharmaceutical formulations

The effect of sodium bisulfite on aspirin hydrolysis was studied at 40 degrees in the pH range of 6.5-7.5. Significant catalytic activity by the sulfite ion was observed. Second-order rate constants were calculated for this catalysis and compared to other buffer species. The sulfite ion was a much more efficient catalyst than acetate, phosphate, or carbonate.