title: Steady-state bioavailability of extended-release methylphenidate (MPH-MLR) capsule vs. immediate-release methylphenidate tablets in healthy adult volunteers.
abstract: OBJECTIVE
  The objective of the study was to determine the relative bioavailability of an extended-release multilayer bead formulation of methylphenidate hydrochloride (MPH-MLR) 80 mg vs. methylphenidate immediate-release (IR; Ritalin(®)) tablets as single and multiple doses in the fed state.
  
  
  METHODS
  A single-center, multiple-dose, randomized, open-label, two-period crossover study conducted in 26 healthy adults assigned to 4 days of once-daily MPH-MLR 80 mg or IR methylphenidate 25 mg three times daily.
  
  
  RESULTS
  MPH-MLR 80 mg produced reproducible biphasic profiles of plasma methylphenidate concentrations characterized by a rapid initial peak, followed by a moderate decline reaching a plateau ~5 h post dose, then a gradual increase culminating in an attenuated second peak ~7 h post dose. Maximum concentration was lower for MPH-MLR 80 mg than IR methylphenidate 25 mg three times daily on day 1 (23.70 vs. 31.47 ng/mL); exposure was similar. The geometric mean ratios (MPH-MLR/IR methylphenidate [90 % CI]) of log-transformed area under the plasma drug concentration-time curve to the last measurable observation (day 1: 0.88 [84.75-91.80]; day 4: 0.84 [81.16-86.94]), and area under the plasma drug concentration extrapolated to infinity (day 1: 0.93 [88.57-97.28]; day 4: 0.88 [84.48-91.17]) were within the 80-125 % bioequivalence range. The mean ± SD MPH-MLR 80-mg capsule day 4 area under the plasma drug concentration vs. time curve from 0 to 4 h (74.5 ± 15.2 ng·h/mL) was greater than IR methylphenidate 25 mg three times daily (66.0 ± 17.4 ng·h/mL), confirming steady-state levels during the study period. All treatment regimens were safe and well tolerated.
  
  
  CONCLUSIONS
  MPH-MLR 80-mg capsule once daily or IR methylphenidate 25 mg three times daily provides comparable maximum methylphenidate concentrations and systemic exposure in the fed state.
authors.affiliation: Rhodes Pharmaceuticals L.P., 498 Washington St, Coventry, RI, 02816, USA, akwete.adjei@pharma.com.
authors.forename: Akwete
authors.initials: A
authors.lastname: Adjei
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Kupper
authors.forename: Nathan S
authors.initials: NS
authors.lastname: Teuscher
authors.forename: Sharon
authors.initials: S
authors.lastname: Wigal
authors.forename: Floyd
authors.initials: F
authors.lastname: Sallee
authors.forename: Ann
authors.initials: A
authors.lastname: Childress
authors.forename: Scott H
authors.initials: SH
authors.lastname: Kollins
authors.forename: Laurence
authors.initials: L
authors.lastname: Greenhill
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D001682:Biological Availability; D002214:Capsules; D002626:Chemistry, Pharmaceutical; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations; D004334:Drug Administration Schedule; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D008875:Middle Aged; D013607:Tablets; D055815:Young Adult
chemical_list: D002214:Capsules; D003692:Delayed-Action Preparations; D013607:Tablets; D008774:Methylphenidate