St. Louis ? Federal prosecutors say Robert Courtney’s 30-year sentence for diluting chemotherapy drugs was “more than warranted.”

Prosecutors filed a brief Thursday with the 8th U.S. Circuit Court of Appeals in St. Louis challenging Courtney’s appeal of his sentence.

In December, Courtney was sentenced to 30 years in prison after the former pharmacist pleaded guilty to 20 counts of misbranding, tampering with and adulterating cancer drugs.

The plea agreement set a sentencing range of 17 to almost 22 years but allowed the judge to sentence Courtney to up to 30 years if the crimes warranted the time.

In the brief, federal prosecutors argued that Courtney’s convictions for diluting drugs represented only 25 percent of the 34 persons he admitted victimizing and just 5 percent of the 158 times he admitted to product tampering.

In February, attorneys for Courtney, 50, filed an appeal with the appellate court arguing that U.S. District Judge Ortrie Smith erred in sentencing Courtney to a longer sentence than was allowed under federal guidelines.

Possible oral arguments in the appeal have not been scheduled. Prosecutors want the hearing set in Kansas City.