There is a new $1.25/1 Robitussin Coupon available. It has no size restrictions, so you can use it on smaller sizes.
Walmart has the Robitussin-To-Go for $.97 – so free + small money maker after coupon.
Robitussin-To-Go, $0.97
Use $1.25/1 Robitussin Product
Free + $0.28 money maker after coupon