1HIMMELSBACH F, LANGKOPF E, ECKHARDT M, et al. 8- [ 3-amino-piperidin-l-yl ] -xanthines, the production thereof and the use of the same as medicaments: WO, 2004018468 [ P]. 2004 - 03 - 04.
2HAAK T, MEINICKE T, JONES R, et al. Initial combination of linagfiptin and metformin improves glyeaemie control in type 2 di- abetes: a randomized, double-blind, placebo-controlled study [J]. Diabetes ObesMetab, 2012, 14(6): 565 -574.
3SCHEEN A J. Efficacy and safety of Jentadueto (linagfiptin plus metformin) [J]. Exp Opini Drug Safet, 2013, 12(2): 275 - 289.
4KOLIAKI C, DOUPIS J. Linagliptin/Metformin fixed-dose com- bination treatment : a dual attack to type 2 diabetes pathophysiolo- gy[J]. Adv Ther, 2012, 29(12): 993-1004.
5DEL PRATO S, TASKINEN MR, OWENS DR, et al. Efficacy and safety of linagliptln in subjects with type 2 diabetes mellitus and poor glycemic control: Pooled analysis of data from three pla- cebo-controlled phase III trials[ J]. J Diabet Complie, 2013, 27 (3) : 274 -279.
6YKI-JARVINEN H, ROSENSTOCK J, I)URAN-GARCIA S, etal. Effects of adding linagliptin to basal insulin regimen for inad- equately controlled type 2 diabetes A 1> 52-week randomized, double-blind study[ J]. Diabetes Care, 2013, 36 (12) : 3875 - 3881.
7HIMMELSBACH F, LANGKOPF E, ECKHARDT M, et al. No- vel 8- ( piperazine-1 -yl ) -and 8 - ( [ 1,4 ] diazepan-1 -yl ) -xanthine, the production and use thereof in the form of a drug: WO, 2005051950 [ P ]. 2005 - 06 - 09.
9ECKHARDTM, LANGKOPF E, MARK M, et al. 8-(3-(R)- aminopiperidin-l-yl )-7-but-2-ynyl-3-methyl-l-( 4-methyl-quin- azolin-2-ylmethyl) -3, 7-dihydropurine-2, 6-dione ( BI 1356) , a highly potent, selective, long-acting, and orally bioavailable DPP-4 inhibitor for the treatment of type 2 diabetes[ J]. J Med Chem, 2007, 50(26): 6450-6453.
10PFRENGLE W, PACHUR T, NICOLA T, et al. Process for the preparation of chiral 8- ( 3-aminopiperidin-1 yl ) -xanthines : US, 20090192314 [ P ]. 2009 - 07 - 30.