Its just your regular amoxicillin that one can get a prescription for. Indications are the same, usually upper respiratory tract infections. Its a very narrow spectrum drug, so for anything more serious, it won't do.
Shelf life is a much debated subject, but it looks like drugs are good well past their expiration dates. See this article: http://www.mercola.com/2000/apr/2/drug_expiration.htm . It requires you enter some email address, not necssarily yours <img src="/images/graemlins/wink.gif" alt="" />