Cesar Caransa-Torres appeals the sentence imposed by the district court * after Caransa-Torres pleaded guilty to drug charges. On appeal, Caransa-Torres’s counsel filed a brief under Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967). Although CaransaTorres was granted permission to file a pro se supplemental brief, he has not done so. Counsel argues the Sentencing Guidelines and statutory minimum terms of imprisonment violate the Separation of Powers Doctrine and the Eighth Amendment. These arguments fail. See Chapman v. United States, 500 U.S. 453, 467, 111 S.Ct. 1919, 114 L.Ed.2d 524 (1991); Mistretta v. United States, 488 U.S. 361, 380-84, 109 S.Ct. 647, 102 L.Ed.2d 714 (1989); United States v. Prior, 107 F.3d 654, 658-60 (8th Cir.), cert. denied, 522 U.S. 824, 118 S.Ct. 84,139 L.Ed.2d 41 (1997).

Having carefully reviewed the record independently under Penson v. Ohio, 488 U.S. 75, 109 S.Ct. 346, 102 L.Ed.2d 300 (1988), we find no nonfrivolous issues. Thus, we affirm the judgment of the district court, and we grant counsel’s motion to withdraw.