DrugPatentWatch provides information on drug patents and their expirations. Datasets include Paragraph IV challenges, tentative approval (an indicator of generic entry), patent claim types, annual sales, patent expirations, failure to pay maintenance fees, ex parte and inter partes reexamination, interference, and disclaimers. Complete details are provided for all FDA-approved small molecule drugs. Annual sales information is available for top-selling drugs. This value-added information supports the critical business functions of patent agents and attorneys, pharmaceutical companies, wholesalers, healthcare payers, and investors.