This is an open-label clinical research study of an oral glycopyrrolate liquid for the treatment of chronic moderate to severe drooling in patients with cerebral palsy or other neurological conditions. Patients participating in the study will receive oral glycopyrrolate liquid (1 mg/5 ml) three times a day (TID) for study duration of 24 weeks. After a washout, screening, and 2-day baseline period, patients will be enrolled in a 4-week dose titration period. Glycopyrrolate liquid doses will be titrated using dose levels in the Dose Titration Schedule. Titration will begin at 0.02 mg/kg per dose TID and sequentially increased in 0.02 mg/kg per dose increments TID every 5-7 days during the first four weeks until optimal individualized response is obtained for each patient or a maximum dose of 0.1 mg/kg TID is reached, not exceeding 3 mg TID or Dose-level 5 in the Dose Titration Schedule, whichever is lesser. Optimal dose for each patient is the dose at which he/she is receiving the maximum benefit from the study drug (greatest improvement in drooling) while experiencing minimum side effects. All patients will receive close attention by study staff throughout the study.