Bioequivalence Study of Zolpidem Tartrate Tablets and Ambien® Under Fasting Conditions

• Maximum Plasma Concentration (Cmax) for Zolpidem Tartrate [ Time Frame: serial pharmacokinetic blood samples drawn prior to dosing (hour 0), and then at 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 4, 5, 6, 8, 10, and 12 hours after dose administration ] [ Designated as safety issue: No ]
  The maximum or peak concentration that zolpidem tartrate reaches in the plasma.
  
  
• Area Under the Concentration Versus Time Curve From Time 0 to Time t [AUC(0-t)] for Zolpidem Tartrate [ Time Frame: serial pharmacokinetic blood samples drawn prior to dosing (hour 0), and then at 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 4, 5, 6, 8, 10, and 12 hours after dose administration ] [ Designated as safety issue: No ]
  The area under the plasma concentration versus time curve, from time 0 to the time of the last measurable zolpidem tartrate concentration (t), as calculated by the linear trapezoidal rule.
  
  
• Area Under the Concentration Versus Time Curve From Time 0 Extrapolated to Infinity [AUC(0-∞)]for Zolpidem Tartrate [ Time Frame: serial pharmacokinetic blood samples drawn prior to dosing (hour 0), then 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 4, 5, 6, 8, 10, and 12 hours after dose administration ] [ Designated as safety issue: No ]
  The area under the zolpidem tartrate plasma concentration versus time curve from time 0 to infinity. AUC(0-∞) was calculated as the sum of AUC(0-t) plus the ratio of the last measurable plasma concentration to the elimination rate constant.
  
  

The purpose of this study is to compare the bioequivalence of a test formulation of zolpidem tartrate tablets to an equivalent oral dose of the commercially available reference drug product Ambien® (zolpidem tartrate tablets) in adult subjects under fasted conditions.

Thirty-eight healthy, non-smoking, non-obese male and female volunteers at least 18 years of age will be randomly assigned in a crossover fashion to receive each of two zolpidem tartrate dosing regimens in sequence with a 7 day washout period between dosing periods. On the morning of Day 1, after an overnight fast of at least 10 hours, subjects will receive either a single oral dose of the test formulation, zolpidem tartrate (1 x 10 mg tablet) or a single oral dose of the reference formulation, Ambien® (1 x 10 mg tablet). After a 7 day washout period, on the morning of Day 8 after an overnight fast, subjects will receive the alternate regimen. Blood samples will be drawn from all participants before dosing and for 12 hours post dose at times sufficient to adequately define the pharmacokinetics of zolpidem tartrate. A further goal of this study is to evaluate the safety and tolerability of this regimen in healthy volunteers. Subjects will be monitored throughout the confinement portion of the study for adverse reactions to the study drugs and/or procedures. Blood pressure and pulse rate will be obtained prior to dosing and at 0.5, 1, 2, 4 and 12 hours post-dose. All adverse events whether elicited by query, spontaneously reported or observed by clinic staff will be evaluated by the investigator and reported in the subject's case report form.