Madame Pearl's Cough Syrup

I bought this in Chinatown, at the back of the Ruby Rouge mall...

According to my grandfather, it is a very popular brand in Hong Kong, although he does not use it himself. On the box, it says that it contains, per 30ml:

• Dextromethorphan HBr: 28.5 mg
• Ephedrine HCl: 7.5 mg
• Chlorpheniramine Maleate: 4.0 mg
• Guaifenesin: 221 mg

When I checked my Robitussin Cough & Cold (Extra Strength), this was what we had in medicinal ingredients adjusted for the same volume of 30 ml (was for 5 ml on box):

• Dextromethorphan HBr: 90 mg
• Pseudoephedrine HCl: 180 mg
• Guaifenesin: 1200 mg

The Robitussin was perhaps Extra Strength, but is a lot more potent. Price-wise, the Madame Pearl's was 5$ for 120 ml and I forgot how much the Robitussin was, but probably around $8-10 for 100 ml.