The history of alcian blue is indeed an interesting one, this not
being the first time it has been going "out of production"
Professor John Scott in the UK spent a considerable portion of his
prfessional life trying to discover the formula of alcian blue.  As a
biochemist, he felt it absolutely necessary for his research to know
the formulation.  British Drug House  BDH (as it then was - now
Merck in the UK and rest of Europe) owned the formula (though
Merck, I believe) and constantly and consistently refused to divulge
the formula.  Ironically, it was almost simultaneous with Scott
working it out for himself, by time-consuming experimentation, that
BDH decided to no longer produce the dye and, if I remember
correctly release the formula (perhaps because a patent expired,
but I am not sure of that).

Russ Allison,
Dental School
Cardiff
Wales