Naproxen Sodium (2 x 220 mg) Fasted Comparative Bioavailability Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Naproxen Sodium (2 x 220 mg) Fasted Comparative Bioavailability Study (NCT03167541), a randomized phase 1 study. The primary outcome is Area Under Plasma Concentration-time at Time t (AUC0-t).

2. Clinical Question

The study is a formulation comparison rather than a trial of clinical benefit in patients. Its question concerns the amount of drug measured in plasma over time after each product, not symptom relief, prevention of illness, or long-term outcomes. The registry describes healthy participants and a fasted comparison; it does not report results for other populations or dosing conditions.

3. Trial Design

The registry describes a Phase 1, randomized, single-dose, 2-way crossover, open-label comparative bioavailability study. Participants were assigned to treatment orders: Test followed by Reference, or Reference followed by Test. In a crossover design, each participant receives both treatments in separate periods, so the comparison can use within-participant information rather than relying only on comparisons between separate groups. The registry lists enrollment of 18.

The trial compared RB naproxen sodium tablets, 2 x 220 mg, with Aleve naproxen sodium tablets, 2 x 220 mg, in the fasted state. The record says the study was conducted to investigate the rate and extent of naproxen absorption and to support registration of the RB formulation. It is marked completed. The listed start date is 2016-10-12 and the primary completion date is 2016-12-02.

Masking is listed as none, so the study was open-label. The registry does not report the treatment-period schedule, washout interval, sequence-generation method, allocation concealment, or adherence details. Although the record names both treatment orders, it does not report how participants were distributed across orders in the posted outcome summaries.

The primary outcome is AUC0-t, reported as a mean with standard deviation and measured in h*μg/mL. Plasma sampling is described from pre-dose through 72 hours post-dose, with planned time points listed across Day 1, Day 2, Day 3, and Day 4. The registry also lists pharmacokinetic secondary outcomes and adverse events. The original statistical plan, including the planned analysis model for the crossover structure, is not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: Total 32 subjects were screened. Of these, 6 subjects were screen failures, 2 were surplus to requirement, 6 were reserve subjects. Subjects randomized were 18.

First Intervention

Washout: 5-8 Days

Second Intervention

Analysis population for the primary outcome, as defined in the registry: Pharmacokinetic (PK) Parameter Summary Set Population includes all subjects from the PK dataset with evaluable PK parameters for each treatment period.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Area Under Plasma Concentration-time at Time t (AUC0-t), measured over Pre-dose and at 15 mins, 30 mins, 45 mins, 1 hour, 1 hour 15 mins, 1 hour 30 mins, 1 hour 45 mins, 2 hours, 2 hours 30 mins, 3, 4, 6, 9, 15 (Day 1), 24, 36 (Day 2), 48 (Day 3) and 72 (Day 4) hours post-dose.

The primary endpoint, AUC0-t, measures the area under the plasma concentration-time curve from administration until the last quantifiable concentration. It combines information about plasma concentration and time, giving a summary of drug exposure over the measured part of the concentration profile. The registry reports the endpoint in h*μg/mL as a mean and standard deviation.

AUC is used in bioavailability comparisons because it describes the extent of systemic exposure. A separate pharmacokinetic measure, such as the time to first observed maximum concentration, can contribute information about the rate of absorption. AUC0-t is not itself a measure of symptom change or clinical benefit; it is a pharmacokinetic endpoint used to compare how much drug reaches the measured plasma concentration profile under the study conditions.

In this study, the posted mean was 915.0 for the test treatment and 909.0 for the reference treatment. The reported mean difference was 6.0, with an interval from -122.6 to 134.6. These summaries describe the observed data, but formal bioequivalence interpretation requires the prespecified criteria and analysis. Those criteria and a sponsor-reported primary analysis are not reported in the registry record.

7. Results Posted in the Registry

• Test: RB Naproxen Sodium 2 x 220 mg: mean 915.00 versus 909.00 on control; difference 6.00 (95% CI -122.56 to 134.56), standardized effect d = 0.03; z-test p = 0.927.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Elimination Rate Constant (Kel)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Test: RB Naproxen Sodium 2 x 220 mg: mean 0.04 versus 0.04 on control; difference -0.00 (95% CI -0.01 to 0.00), standardized effect d = -0.01; z-test p = 0.969.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Test: RB Naproxen Sodium 2 x 220 mg and the control. The interval gives the range of effects that remain compatible with the data.

Area Under the Plasma Concentration Curve From Administration to Infinity (AUC0-inf)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Test: RB Naproxen Sodium 2 x 220 mg: mean 972.00 versus 963.00 on control; difference 9.00 (95% CI -133.41 to 151.41), standardized effect d = 0.04; z-test p = 0.901.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Test: RB Naproxen Sodium 2 x 220 mg and the control. The interval gives the range of effects that remain compatible with the data.

Residual Area (AUC%Extrap)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Test: RB Naproxen Sodium 2 x 220 mg: mean 5.68 versus 5.58 on control; difference 0.10 (95% CI -1.13 to 1.33), standardized effect d = 0.05; z-test p = 0.873.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Test: RB Naproxen Sodium 2 x 220 mg and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes cover additional aspects of pharmacokinetics, including elimination rate, total exposure extrapolated to infinity, residual area, time to maximum concentration, half-life, and plasma concentrations at planned sampling times. The registry also lists adverse events among the secondary outcomes. The posted numeric summaries are available for only some of the listed secondary outcomes; the registry record does not report sponsor analyses for the secondary results.

Across the secondary pharmacokinetic measures with posted summaries, the treatment means are close in their reported central values. The associated uncertainty intervals are broad enough that the summaries do not sharply distinguish the treatments. This general pattern is consistent with the primary result's small point estimate and uncertain comparison, but consistency among summary measures does not constitute an independent demonstration of bioequivalence.

Secondary results generally carry less weight than a prespecified primary endpoint because they may be numerous, exploratory, or less central to the trial question. When multiple outcomes are examined, some may appear notable by chance unless the analysis plan accounts for multiplicity. The registry record does not report a multiplicity adjustment, a hierarchy for testing secondary endpoints, or a prespecified interpretation plan. The secondary comparisons are therefore best treated as descriptive context rather than confirmatory evidence.

Outcome definitions and the presence of a posted result do not establish that an endpoint was analyzed according to a particular model. The record does not report the analysis method for these secondary outcomes, their confidence levels, or how missing concentration measurements were handled. The broader pattern can help describe the pharmacokinetic profile, but the limitations in analysis detail and multiplicity make strong conclusions from secondary comparisons unwarranted.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Elimination Rate Constant (Kel)
• Area Under the Plasma Concentration Curve From Administration to Infinity (AUC0-inf)
• Residual Area (AUC%Extrap)
• Time Until Cmax is First Achieved (Tmax)
• Plasma Concentration (Elimination) Half-life (T1/2)
• Plasma Concentration at Each Planned Nominal Time-point (Cn)
• Occurrence of Adverse Events (AEs)

9. Statistical Interpretation

10. Statistical Methods Explained

What do the means and standard deviations describe?

A mean is a measure of the center of the observed values. For AUC0-t, the registry reports mean values of 915.0 for the test treatment and 909.0 for the reference treatment. A standard deviation describes how dispersed observations are around a mean; it is not a confidence interval for the mean and is not the same thing as the uncertainty in the treatment comparison. The posted standard deviations are 207.0 and 186.0, respectively.

In a crossover study, each participant receives both treatments. The main comparison can therefore be based on the treatment difference within each participant. This can account for stable differences between participants, provided the analysis uses the paired structure appropriately. The registry record does not report the model or test used for the primary comparison, or whether the posted analysis used paired participant-level data. The separate treatment means and standard deviations cannot recover the paired differences or their variability.

How should the mean difference be read?

The reported primary estimate is a mean difference of 6.0, calculated in the posted results as test minus reference. A positive estimate means the posted test mean is numerically higher than the reference mean; it does not by itself establish a meaningful difference. The estimate is a point estimate, meaning it is the single best summary of the contrast under the reported calculation. Other values remain plausible given the uncertainty interval.

The registry reports an interval from -122.6 to 134.6. A confidence interval is a range generated by a statistical procedure to convey uncertainty around an estimate. In general, a wider interval indicates less precision than a narrower interval. The confidence level and detailed procedure for this interval are not reported in the registry record, so its exact repeated-sampling interpretation cannot be specified from the registry information. In this case, the interval includes no difference and extends in both directions around the estimate.

What does the p-value add?

The unadjusted p-value for the primary comparison is 0.927. A p-value measures the compatibility of data with a specified null hypothesis under an analysis model. It does not quantify the probability that the null hypothesis is true, and it does not tell whether an effect is important. It also cannot establish bioequivalence: that requires a defined equivalence or bioequivalence margin and an analysis designed to evaluate whether the uncertainty lies within that margin. The margin and sponsor-reported test are not reported in the registry record.

The term unadjusted means the reported value is not described as corrected for multiple comparisons. It should not be interpreted as accounting for the several pharmacokinetic outcomes in the record. The registry does not report a multiplicity procedure.

Why does the crossover structure matter?

A crossover design can improve the efficiency of a comparison when each participant's response to both treatments is available and the within-person contrast is analyzed. It also depends on design and analysis details, including suitable separation between treatment periods and consideration of possible period or sequence effects. These details and the primary analysis model are not reported in the registry record. The posted arm summaries alone do not show whether the potential efficiency of pairing was used.

The registry identifies the PK parameter summary set as subjects from the PK dataset with evaluable PK parameters for each treatment period. It does not report the exact analysis population count, missing measurements, exclusions, or how incomplete profiles were handled. Those omissions limit interpretation of how the analysis population relates to the registry's enrollment entry.

Why can over-dispersion matter?

General statistical explanation: when observations vary more than a model assumes, uncertainty can be understated if the analysis does not account for that extra variability. For a crossover pharmacokinetic comparison, the relevant variability includes variation in within-participant treatment differences, which cannot be read directly from the separate arm standard deviations. The registry does not report a variance model or enough participant-level information to assess this issue.

General statistical explanation: statistical precision depends on both the size of the estimated contrast and the variability of the data, as well as the analysis design. A small estimated contrast does not guarantee a precise result if uncertainty remains broad. The posted interval is therefore important alongside the point estimate and p-value.

The posted primary comparison is a summary-level result, not a full account of the prespecified statistical method. The registry record does not report the original statistical analysis plan, the confidence level for the interval, a sample-size justification, or interim analyses. No claim about those unreported design choices can be inferred from the posted means and comparison.

11. Confidence Intervals and Precision

The primary mean difference is 6.0 h*μg/mL, with a reported interval from -122.6 to 134.6. This interval spans values below and above no difference, so the direction and size of the underlying contrast are not tightly determined by the posted estimate. The point estimate is near no difference in comparison with the range of values covered by the interval, but the interval still allows materially different mean contrasts in either direction.

A confidence interval communicates uncertainty around an estimate; it does not mean that every value inside the interval is equally likely, and it does not give the probability that the true effect falls within that particular range. The confidence level and calculation procedure are not reported in the registry record. Accordingly, the interval can be read as evidence of uncertainty, but not assigned a more specific coverage interpretation from the registry information.

The treatment means have standard deviations of 207.0 for the test and 186.0 for the reference. These values show spread in the outcome data, but the crossover comparison's precision also depends on the within-participant covariance. That information, participant-level data, and the analysis model are not reported. The summary estimates therefore do not fully reveal how the paired design contributed to precision.

Precision and equivalence are related but distinct. A narrow interval entirely within a prespecified bioequivalence range can support an equivalence conclusion under a suitable analysis. The registry record does not report such a range or a sponsor-reported bioequivalence analysis. The posted interval should therefore be read as a summary of uncertainty, not as a formal decision that the products are equivalent or different.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm, not total events. They are illustrations based on the observed effect, rather than the trial's original design assumptions. The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect to detect set at the stated fraction of the observed effect. The original trial's sample-size assumptions are not reported in the registry record.

The 80% power column describes the number of participants per arm that the planning calculation estimates would give an 80% chance of detecting the specified effect under those assumptions, if that effect and model were correct. The 90% power column makes the corresponding calculation for a higher chance of detection. These are planning targets, not guarantees about what a future study will find.

For the primary endpoint, planning for 100% of the observed effect gives 16,885 participants per arm for 80% power and 22,605 participants per arm for 90% power. Planning for 75% of the observed effect gives 30,018 and 40,186 participants per arm, respectively; planning for 50% gives 67,540 and 90,417. The smaller the effect to be detected, the more participants the calculation requires, because a smaller contrast is harder to distinguish from random variation under the stated assumptions.

These figures are planning illustrations, not observed power. They are based on the posted observed effect and do not establish the probability that the completed trial detected an effect. They also do not replace the original crossover design calculations, which are not reported in the registry record. The planning assumptions describe the calculation behind the illustrations, not necessarily the analysis or design used for the trial.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 6.000; pooled standard deviation σ = 196.780.
2. n = 2 × (1.96 + 0.842)² × 196.780² / 6.000² = 16,884.9, rounded up to 16,885 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 6                      # observed difference in means
sigma <- 196.780334383291                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(3167541)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 16,885 (80% power), 22,605 (90% power)
 75% of observed effect: n per arm = 30,018 (80% power), 40,186 (90% power)
 50% of observed effect: n per arm = 67,540 (80% power), 90,417 (90% power)
power.t.test: 16885.9 
Simulated power at n = 16,885 per arm: 0.791 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry lists multiple pharmacokinetic outcomes, including the primary AUC0-t endpoint and secondary measures of elimination, exposure, residual area, timing of peak concentration, half-life, and plasma concentration at planned time points. When a study examines multiple outcomes, the chance of obtaining apparently unusual results can increase unless the analysis plan controls or otherwise addresses multiplicity. This is a general statistical concern, not evidence that a particular result in this study is false.

The registry record does not report a multiplicity adjustment, a prespecified testing hierarchy, or which secondary outcomes were intended to be confirmatory. It also does not report sponsor analyses for the posted secondary summaries. Their p-values, where displayed in the posted comparisons, are unadjusted and should not be treated as if they account for all outcomes examined.

Information about missing data and analysis populations is limited. The primary endpoint definition says the PK parameter summary set includes subjects from the PK dataset with evaluable PK parameters for each treatment period. The registry lists enrollment of 18 and an arm summary n of 18 for each treatment, but does not report the exact participant flow into the PK set, missing samples, exclusions, or reasons for any unavailable measurements. The effects of incomplete profiles on the analysis cannot be assessed from the registry record.

The registry does not report the original statistical analysis plan, the crossover model, treatment of period or sequence effects, or the confidence level for the intervals. It also does not report interim analyses or the sample-size justification. These absences limit assessment of whether the posted comparisons follow the planned analysis and how robust the results are to analytic choices. They do not justify assuming that any particular procedure was or was not used outside what the record states.

15. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The serious adverse event summaries report zero serious adverse events in the test group and zero in the reference group. The record lists 18 participants at risk in each treatment group for this outcome. No deaths are reported in either group. These counts describe what was posted for the study; they do not establish that the treatments have identical safety profiles.

The record also lists one other adverse event in the test group and none in the reference group, with 18 at risk in each. The registry does not provide further details about event type, severity, timing, relatedness assessment, or participant-level recurrence. The serious-event figures should be interpreted as counts in this study, not as proof that serious events cannot occur.

Safety observations from a small, single-dose study in healthy participants have limited scope for describing uncommon events, longer-term exposure, or experience in other populations. The registry record does not provide enough detail to characterize the broader safety profile. These data describe reported events during this trial and are not a basis for treatment decisions.

16. What the Result Does, and Does Not, Mean

The posted results show that the test and reference treatment means for the primary AUC0-t outcome were close, with a reported mean difference of 6.0 h*μg/mL. The interval from -122.6 to 134.6 reflects substantial uncertainty around that estimate. The unadjusted p-value of 0.927 does not establish that the products are equivalent; a nonsignificant difference test and a formal equivalence assessment answer different questions.

The study was designed as a comparative bioavailability investigation in healthy participants under fasted conditions, with a single dose and crossover treatment order. Its results concern the measured pharmacokinetic outcomes in that setting. They do not directly establish clinical effectiveness, long-term safety, performance in patients, or results under fed conditions. Those questions are not addressed by the posted summaries.

Formal bioequivalence conclusions depend on prespecified criteria and an appropriate analysis of the pharmacokinetic data. The registry record does not report the bioequivalence margin, the confidence level or method for the posted interval, or the sponsor's own primary analysis. The summary-level result therefore cannot establish whether regulatory bioequivalence criteria were satisfied. The registry record states the study's registration-support purpose, but that purpose alone is not a result.

The record reports no serious adverse events in either treatment group and one other adverse event in the test group versus none in the reference group. These observations are limited to the trial and do not establish comparative safety beyond its circumstances. Overall, the results provide descriptive evidence about plasma exposure and reported adverse events; they should not be extended beyond the population, dosing condition, and endpoints described in the record.

17. Why This Trial Matters Statistically

This trial illustrates a recurring issue in bioequivalence interpretation: a small point estimate does not necessarily mean that the result is precise enough to demonstrate equivalence. The primary mean difference is 6.0, but its interval extends on both sides of no difference. The uncertainty interval, the prespecified acceptance range, and the analysis structure are all important to the interpretation; the registry record reports only some of that information.

The crossover design is also statistically important. Comparing each participant under both formulations can reduce the influence of stable differences between participants, when the paired data are analyzed appropriately. Yet the posted treatment-level means and standard deviations do not reveal within-participant variability. Without the crossover analysis model or participant-level paired information, readers cannot determine how the design affected the precision of the comparison.

The planning illustrations make the role of effect size visible: smaller effects require larger samples under the stated planning assumptions. They are not observed power and do not reconstruct the trial's original design rationale. Their interpretation is separate from the completed study's observed estimate and uncertainty.

Finally, this record distinguishes a comparative pharmacokinetic study from a clinical outcome trial. Its principal contribution is to describe exposure after the test and reference products under specified conditions. The posted summaries are useful for understanding that narrow question, while the missing analysis details and formal equivalence criteria prevent a definitive conclusion about regulatory bioequivalence from these summaries alone.

18. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The most important limitation for interpretation is the absence of the sponsor-reported primary analysis and the prespecified bioequivalence margin in the registry record. The posted mean difference and interval are not enough to determine whether formal bioequivalence criteria were met. The confidence level and calculation method for the interval are also not reported.

Although this is a crossover study, the registry does not report the analysis model, within-participant correlation, paired differences, or treatment of period and sequence effects. Separate treatment means and standard deviations cannot supply that information. The washout interval and other details relevant to treatment-period separation are not reported either.

The registry describes a PK parameter summary set based on evaluable parameters in each treatment period, but does not report participant flow into that set or the handling of missing concentration measurements. It lists enrollment of 18 and n of 18 for each treatment summary; those entries do not by themselves explain exclusions, completeness of profiles, or the relation between enrollment and the analysis population.

The study is described as open-label and conducted in healthy participants in the fasted state after a single dose. Its summaries therefore have limited scope for other populations, dosing conditions, or longer-term outcomes. The record does not report detailed participant characteristics, adherence, or product sourcing beyond the named treatments. Multiple secondary outcomes are listed, but multiplicity procedures and a testing hierarchy are not reported. These limitations constrain interpretation without proving that the results are biased or that an unreported procedure was not used.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Naproxen Sodium (2 x 220 mg) Fasted Comparative Bioavailability Study — NCT03167541.
• Registry record last updated 2019-02-28; status last verified 2019-02.
• Results first posted 2019-02-28.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

22. Record Summary

The registry describes a completed Phase 1, randomized, open-label, single-dose, 2-way crossover comparison of test RB naproxen sodium tablets, 2 x 220 mg, and reference Aleve naproxen sodium tablets, 2 x 220 mg, in healthy participants in the fasted state. Enrollment is listed as 18. The study's stated purpose was to investigate naproxen absorption and support registration of the test formulation.

The primary endpoint was AUC0-t. The posted treatment means were 915.0 for test and 909.0 for reference, with a mean difference of 6.0 and an interval from -122.6 to 134.6. The registry record does not report the formal bioequivalence margin or sponsor-reported primary analysis needed to interpret these summaries as a regulatory equivalence decision.

The record reports zero serious adverse events in each group and no deaths. It does not report the original statistical analysis plan, detailed missing-data handling, or multiplicity procedures.