Can Tribvit be "counterfeited"? Idea of stability in gelules?

Tablets excipients are:  

calcium hydrogen phosphate dihydrate, microcrystalline cellulose, sodium starch glycol late, magnesium stearate, colloidal anhydrous silicon dioxide.

The first, I mean is not available in pharmacies. In any case, I would exclude lactose and replace it with mannitol. Also Avicel PH 101   or 102 I would use along with dried starch. Starch can be   dried in a warm air oven at 120 ° C. Mgstearate and Coll SiO2   can be added it is impossible to specify a stability date without stability research. But kept in the presence of a dry stopper in a well-closing dark Bruiun glass bottle I would dare   assign a shelf life of half a year.