So I was just looking into this today and Marie Gale wrote a great blog post about it.
http://blog.mariegale.com/more-on-lip-balm/Basically, the term 'lip balm' is now considered to be generic and does not automatically mean the product is a drug. However, if you claim that your lip balm is anything more than a cosmetic (it will cure chapped lips) then you've made a drug claim and you need to go through the testing and evaluation to sell that product as an over the counter drug. But, moisturizing is considered to be a cosmetic claim and not a drug claim - so you are safe to say that your lip balm moisturizes and the rules for cosmetics will still apply.
Do keep in mind though that the FDA has not specifically and publicly put out a clarifying statement on this particular issue. The answer Marie Gale got was sent to her privately from the FDA and it's impossible to know if it is absolutely correct or not. So in the end, calling your product a 'lip butter' is the safest - but if you've already printed your labels and signs and made your website full of lip balms, you are probably fine, too.
Hope this helps!