Bioequivalence and Bioavailability Forum

Dear Mei San

❝ Is BE possible to be achieved if the reference product used in BE study is sugar-coated (Buscopan), whereas the test product is film-coated?

Yes, why not? As a quaternary ammonium compound, hyoscine butylbromide is highly polar and hence only partially absorbed following oral administration. After oral administration of single doses of hyoscine butylbromide in the range of 20 to 400 mg, mean peak plasma concentrations between 0.11 ng/mL and 2.04 ng/mL were found at approximately 2 hours. Test and reference are both IR formulations and unless they do not differ in dissolution behaviour BE should be possible. However, according to the Australian TGA ARGOM Appendix 1: Guidelines on efficacy and safety aspects of OTC applications bioequivalence data are generally not required for hyoscine butylbromide. So you may can think of a BCS class III biowaiver.