INTUNIV(TM) is product of Shire plc and contains 1 mg, 2 mg, 3 mg, and 4 mg guanfacine hydrochloride extended release tablets. This product has 3 patents listed in orange book; US5854290 ("the '290 patent") titled Use of Guanfacine in the Treatment of Behavioral Disorders; US6287599 ("the '599 patent") and US6811794 ("the '794 patent") both titled Sustained Release Pharmaceutical Dosage Forms with Minimized pH Dependent Dissolution Profiles. The three patents expire in 2015, 2020 and 2022, respectfully. Previously Teva, Actavis and Anchen has already filed ANDA with paragraph IV certification and Shire has subsequently initiated litigation and all the cases are in discovery phase. Recently Watson Labs. has also filed ANDA for generic version of INTUNIV(TM) with paragraph IV certification but only for 4 mg strentgh. INTUNIV(TM) has NP (New Product) exclusivity till 02-September-2012, so no any ANDA will get approval till this date.