Bioequivalence and Bioavailability Forum

hello,
my question is about carbocystein (carbocisteine).
Long time ago we used MUCOPRONT 375 mg capsules (carbocisteine), by Heinrich Mack Nachf. GmbH & Co (Germany) as reference drug in bioequivalence study. Heinrich Mack is part of Pfizer now. Mucopront was withdrawn 22-Jul-2005.

Selection of MUCOPRONT capsules as reference drug is in question now by regulatory agency. I couldn't find any information about first marketing authorization date of MUCOPRONT capsule by Heinrich MACK, or was it authorized as reference drug in Germany according to full preclinical and clinical data? I tried to contact Bfarm, by sending a milion of e-mails, but nobody answers!
Please, provide any help.