Contact Lens Solution (Hard/Gas-Permeable) (Mumbai)

Hi all,
I visited ten shops so far, but haven't been able to find it, so I hoped one of you might be able to help. All chemists and opticians seem to stock solution for soft lenses, but I have found none who has hard lens solution.

So, where can I buy contact lens solution for gas-permeable/hard contact lenses in the city?

Any tips?

Thanks.
Sanne