Yes, NEOMYCINS is a Scrabble word!

Letter values in Scrabble US: N 1, E 1, O 1, M 3, Y 4, C 3, I 1, N 1, S 1.

Is it a valid word?

NEOMYCINS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

an antibiotic obtained from an actinomycete and used (as a sulphate under the trade name Neobiotic) as an intestinal antiseptic in surgery

Not playable in Scrabble US: FRADICIN, NEOBIOTIC.