Never tried powder myself, but from what I have read seems to be just as effective. Easiest way I have read to take it is dissolve all 5g in 100ml pure alchohol (like ever clear or what have you). That should give you a 50mg/ml suspension.
but that is pharmacie price. For a box of 3. That's way i always say, the Zambons are not only the best, but the cheapest. You cannot beat that price with any Winny V.