title: Pharmacokinetic comparison of two nicotine transdermal systems, a 21-mg/24-hour patch and a 25-mg/16-hour patch: a randomized, open-label, single-dose, two-way crossover study in adult smokers.
abstract: BACKGROUND
  A comparison of the 21-mg NiQuitin patch with other marketed nicotine patches reported significant differences in pharmacokinetic profiles, even among patches of the identical labeled dose strength. The 25-mg Nicorette Invisi patch became available in the United Kingdom at the end of 2008. No published studies have directly compared the pharmacokinetic profile of this new patch with that of the 21-mg NiQuitin patch.
  
  
  OBJECTIVE
  This study was conducted to compare the single-dose pharmacokinetics of the 21-mg/24-hour patch and the 25-mg/16-hour patch. To determine whether any pharmacokinetic differences might be related to differences in wear time, a post hoc exploratory analysis evaluated the nicotine delivery profiles of the patches under the assumption that the 21-mg patch was removed after 16 rather than 24 hours.
  
  
  METHODS
  This was a single-center, randomized, open-label, single-dose, 2-way crossover study in healthy adults who smoked >10 cigarettes per day in the 6 months before the study. Eligible subjects were housed at the study center for 2 baseline and 2 treatment sessions; no smoking was permitted during the baseline or treatment sessions. Subjects were allocated to receive either the 21-mg patch (removed after 24 hours) or the 25-mg patch (removed after 16 hours) during the first treatment session, after which they crossed over to the alternative sequence in the second treatment session. Blood samples were obtained at predetermined time points before and after patch application. The primary pharmacokinetic parameter was the AUC(0-infinity), an indication of total nicotine exposure. Secondary pharmacokinetic parameters included AUC(0-t), C(max), and T(max). Post hoc exploratory parameters were the AUC(0-16) and the AUC(0-infinity) assuming a 16-hour application time for the 21-mg patch. The differences in AUC(0-infinity), AUC(0-t), Cmax, AUC(0-16), and AUC(0-infinity) assuming a 16-hour application time for the 21-mg patch were considered significant if the lower limit of the 90% CI for the geometric mean ratio (21 mg:25 mg) was >100%. T(max) values were compared using a signed-rank test. Adverse events were elicited using a standard open-ended question on each day of confinement; spontaneously reported events were also captured. The topical effects of the patch (erythema; edema; extent of erythema/papules/pustules; self-reported pruritus) were assessed by study staff before patch application and 1 and 8 hours after patch application using a 4-point rating scale; any topical effects were recorded as adverse events.
  
  
  RESULTS
  Fifty otherwise healthy smokers (29 men, 21 women) were enrolled; 47 (94%) were white. Their mean (SD) age was 31.5 (9.57) years (range, 20-53 years), mean weight was 70.24 (9.56) kg (range, 51.0-95.9 kg), and mean height was 173.0 (8.02) cm (range, 156-194 cm). Subjects reported smoking between 11 and 40 cigarettes per day before the study. The AUC(0-infinity) was significantly higher for the 21-mg patch worn for 24 hours than for the 25-mg patch worn for 16 hours (382.36 vs 243.69 ng/mL . h, respectively; geometric mean ratio: 156.90%; 90% CI, 148.10%-166.23%; P < 0.001). T(max) was reached significantly sooner with the 21-mg patch than with the 25-mg patch (6.0 vs 12.0 hours; P < 0.001). C(max) was significantly higher for the 21-mg patch compared with the 25-mg patch (18.34 vs 16.56 ng/mL; geometric mean ratio: 110.72%; 90% CI, 104.82%-116.94%; P < 0.01). The exploratory analyses suggested that the 21-mg patch applied for 16 hours may provide greater total nicotine exposure than the 25-mg patch applied for 16 hours. Although most subjects reported adverse events (75.0% with the 21-mg patch, 89.8% with the 25-mg patch), the majority of these events were mild.
  
  
  CONCLUSIONS
  In this single-dose study in adult smokers, the 21-mg patch was associated with significantly greater nicotine exposure compared with the 25-mg patch. The 21-mg patch provided a maximal nicotine concentration faster than did the 25-mg patch.
authors.affiliation: GlaxoSmithKline Consumer Healthcare, Parsippany, New Jersey 07054, USA. angela.m.deveaugh-geiss@gsk.com
authors.forename: Angela M
authors.initials: AM
authors.lastname: DeVeaugh-Geiss
authors.forename: Lilan H
authors.initials: LH
authors.lastname: Chen
authors.forename: Mitchell L
authors.initials: ML
authors.lastname: Kotler
authors.forename: Lisa R
authors.initials: LR
authors.lastname: Ramsay
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Durcan
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D019540:Area Under Curve; D002626:Chemistry, Pharmaceutical; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009538:Nicotine / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D018722:Nicotinic Agonists / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D012907:Smoking
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine