You'll will need to do the same for all the other vendors that sell it, editing each of their specific chests to remove the potion, and the LItemPotionCureHMS levelled list needs editing also as that supplies extra potions to mechants chests. It should just leave a blank space with all the other items in his chest intact. You will need to copy that whole container record for Lucan into a new mod, call it something like 'Vendors don't sell cure disease potion', and in your new mod right-click and remove the entry for the potion.

Lucan in Riverwood for example - EDID is MerchantRiverwoodTraderChest, and if you scroll down through all his items he has for sale you'll find an entry for 1 potion of cure disease. You'll find all merchant chests in the Containers cateogory in TES5edit. Its in the levelled list - LItemPotionCureHMS but unfortunately its also added into vendors chests as a single potion which means you'll have to go through and edit each vendors specific chests. For some reason my mages end up with self-made enchanted armour in the end anyway. I assume you mean the 'potion of cure disease' that merchants and vendors sell. Enchant won't really create any useful items unless it is leveled fairly high, as for example the stuff you can get during the College of Winterhold quests is already really good mage eq.