Wyeth UK - Robitussin: Robitussin Dry Cough Medicine - nb only this one type contains the "Active ingredient:Dextromethorphan hydrobromide."
Erowid DXM Vault : Complete Guide to DXM in Non-Prescription Drugs: " list of more than 80 non-prescription medications containing various forms of DXM. Listed are the active ingredients (as of 2001) and any relevant notes or cautions"
The highest pure dosage is "DexAlone
Active Ingredients (per gelcap):
DXM Hydrobromide (30mg)
Notes: Manufactured by DexGen"
DexGen Pharmaceuticals, Inc. Interesting site esp as it mentions P Holfords bug bear - homocysteine....