I take the drug you have described. It is 800 mg
Neurontin. The reason you couldn't find anything is that the imprint looks like "HT 26" but if you carefully examine it, the cross line is slightly slanted, so it is supposed to be "NT 26".
This drug is used for epilepsy and for chronic pain syndromes such as fibromyalgia.
Neurontin has many side effects and is useful only when used on a sustained basis. A single pill will have little useful effect. For some people, it is extremely sedating and the 800 mg level could cause serious problems.
Under no circumstances should it be used without careful monitoring by a physicians. This is not a safe drug.
Regards,
Craig K. Elliot