Your pill might be Ritalin (methylphenidate hydrochloride) marketed in New Zealand and Australia - and maybe other parts of the word. This description is from a New Zealand database and confirmed with a US resource containing foreign imprints:
Ritalin 10 mg: round white tablet, marked "CG" on one side and "AB" with a break-line on the other
I'm not a pharmacist or a medical doctor. This message is not medical advice nor is it an offer to provide medical advice. All drug identifications should be validated by a licensed MD or pharmacist.
I have the same question. I have something that is supposed to be 10 mg Ritalin made by Novartis. It is a white tablet with CG imprinted on one side and AB on the other side. It just does not look like any Ritalin I have ever seen before. Did anyone find out whether it is really Ritalin?