Venlafaxine Hydrochloride 150 mg Extended-Release Capsules Under Fasting Conditions: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Venlafaxine Hydrochloride 150 mg Extended-Release Capsules Under Fasting Conditions (NCT01260896), a randomized phase 1 study. The primary outcome is Cmax of Venlafaxine..

2. Clinical Question

This is a pharmacokinetic comparison, rather than a trial designed to assess a clinical benefit or disease outcome. The registry describes bioequivalence based on venlafaxine Cmax and also posts a sponsor analysis expressed as the test-to-reference ratio of geometric means. Cmax is one measure of the concentration profile after dosing; the additional posted endpoints address other concentration measures for venlafaxine’s metabolite, O-desmethylvenlafaxine.

The test product and reference were compared under fasting conditions. The record identifies randomization and a crossover model, so the design is intended to compare both products within a crossover study framework. The registry does not report the detailed dosing sequence, washout conditions, or the criteria used to determine bioequivalence. Those details therefore cannot be inferred from the posted results.

3. Trial Design

The registry describes a randomized, 2-way crossover study in healthy subjects, with no masking. The stated objective was to compare the rate and extent of absorption of venlafaxine hydrochloride 150 mg extended-release capsules with Effexor® XR 150 mg extended-release capsules under fasting conditions. Both products were administered as 1 x 150 mg extended-release capsule. The sponsor was Teva Pharmaceuticals USA. The record lists the study as Phase 1 and completed, with start recorded as 2002-09 and primary completion as 2002-10.

A crossover design exposes participants to both treatments in different sequences, allowing comparisons that can account for participant-level differences when the analysis uses the paired structure appropriately. The adverse-event groups are labeled Test First and Reference First, consistent with the presence of treatment sequences. The posted record does not describe the full sequence allocation, period schedule, washout interval, or other operational details, so these should not be assumed.

The registry reports an enrollment of 24. The primary outcome description states that samples from all participants who completed the study were analyzed. The outcome summaries report 22 observations for each product. The record does not explain the difference between enrollment and the outcome counts, nor does it provide further detail on missing samples or exclusions.

The primary outcome is venlafaxine Cmax, measured in ng/mL from blood samples collected over a 36 hour period. The sponsor-reported analysis gives a ratio of test to reference geometric means and a 90% confidence interval. Additional outcomes cover Cmax, AUC0-t, and AUC0-inf for O-desmethylvenlafaxine. The registry does not report a full statistical analysis plan or the original sample-size justification.

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.

First Intervention

Reasons for not completing this period:

Washout of 7 Days

Second Intervention

Analysis population for the primary outcome, as defined in the registry: All participants that completed the study had their samples analyzed.

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 Cmax of Venlafaxine., measured over Blood samples collected over a 36 hour period..

The primary endpoint is venlafaxine Cmax: the maximum observed concentration of the drug substance in plasma. The registry reports it in ng/mL and states that blood samples were collected over a 36 hour period. Cmax summarizes the peak concentration observed in the sampling profile. It is one measure of the rate and extent of absorption and is used in the record’s stated bioequivalence assessment.

In general, pharmacokinetic endpoints describe concentrations over time after administration. Cmax focuses on the peak, while area-under-the-curve measures describe exposure across a sampling interval or an extrapolated interval. These measures answer related but distinct questions; a similarity in one does not automatically establish similarity in every other measure.

The posted arm summaries give arithmetic means and standard deviations for Cmax. The sponsor’s own reported analysis instead uses the ratio of test-to-reference geometric means, with a 90% confidence interval. These summaries are not interchangeable: the ratio-scale analysis describes relative concentrations on a geometric scale, whereas a mean difference describes an absolute difference between arithmetic means. The registry labels the sponsor analysis as an equivalence or non-inferiority type analysis but does not report its method or the acceptance limits used. Thus, the endpoint and reported estimate can be described, but the registry record alone does not establish which formal decision criteria were applied.

7. Results Posted in the Registry

• Venlafaxine Hydrochloride (Test): mean 124.75 versus 117.69 on control; difference 7.06 (95% CI -21.38 to 35.50), standardized effect d = 0.15; z-test p = 0.627.

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.

Cmax of O-Desmethylvenlafaxine.

• 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:
  • Venlafaxine Hydrochloride (Test): mean 192.33 versus 167.42 on control; difference 24.91 (95% CI -25.28 to 75.10), standardized effect d = 0.29; z-test p = 0.331.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Venlafaxine Hydrochloride (Test) and the control. The interval gives the range of effects that remain compatible with the data.

AUC0-t of O-Desmethylvenlafaxine.

• 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:
  • Venlafaxine Hydrochloride (Test): mean 4,539 versus 4,175 on control; difference 364.73 (95% CI -827.12 to 1,557), standardized effect d = 0.18; z-test p = 0.549.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Venlafaxine Hydrochloride (Test) and the control. The interval gives the range of effects that remain compatible with the data.

AUC0-inf of O-Desmethylvenlafaxine.

• 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:
  • Venlafaxine Hydrochloride (Test): mean 6,797 versus 6,928 on control; difference -130.51 (95% CI -1,673 to 1,412), standardized effect d = -0.05; z-test p = 0.868.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Venlafaxine Hydrochloride (Test) and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes extend the pharmacokinetic description to O-desmethylvenlafaxine, using Cmax, AUC0-t, and AUC0-inf. Across these endpoints, the sponsor-reported geometric-mean ratios are above 100 for Cmax and AUC0-t, while the AUC0-inf ratio is below 100. The corresponding 90% confidence intervals differ in width and location. This broad pattern shows that the direction and uncertainty of the relative estimate are not identical across all metabolite measures.

These results provide context alongside the primary venlafaxine Cmax analysis, but they do not answer the primary question in its place. The metabolite measures describe different aspects of concentration and exposure, and their findings should be interpreted endpoint by endpoint rather than combined into a single conclusion. The registry does not report a unified interpretation or a prespecified hierarchy among the secondary endpoints.

Unadjusted secondary results carry less weight because multiple outcomes create more opportunities for apparently notable findings by chance when each is examined separately. General explanation: multiplicity refers to the increased chance of false-positive conclusions when several hypotheses are tested without an appropriate plan to control or interpret that risk. The record does not report a multiplicity adjustment or a strategy for prioritizing secondary analyses. The sponsor ratios are posted, but the absence of detailed methods and decision limits means they do not establish a formal secondary bioequivalence conclusion on their own.

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

• Cmax of O-Desmethylvenlafaxine.
• AUC0-t of O-Desmethylvenlafaxine.
• AUC0-inf of O-Desmethylvenlafaxine.

9. Statistical Interpretation

10. Statistical Methods Explained

The registry posts two kinds of comparisons for the primary outcome. The sponsor-reported result is a test-to-reference ratio of geometric means with a 90% confidence interval. Separately, the recalculation uses arithmetic means and standard deviations to estimate an unadjusted mean difference. These answer related questions but use different scales and analysis approaches.

What does the reported ratio describe?

The test-to-reference geometric-mean ratio expresses the test product’s geometric mean relative to the reference product’s geometric mean, multiplied by 100. A value of 100 would represent equal geometric means on this scale. The recorded estimate is 106.84, with a 90% confidence interval from 100.54 to 113.54. The interval describes uncertainty around the ratio estimate under the sponsor’s analysis. The registry does not report the analysis method or equivalence limits, so a formal decision cannot be reconstructed from the ratio and interval alone.

Geometric means are often used for pharmacokinetic measures because concentration data can be skewed and analyses may operate on a logarithmic scale. General explanation: on a log scale, differences correspond to ratios when transformed back to the original scale. This can make a relative comparison more appropriate than an absolute difference for some pharmacokinetic questions. The specific reason and model used in this trial are not reported in the registry record.

What does the recalculated mean difference describe?

The recalculation subtracts the reference arithmetic mean from the test arithmetic mean using the posted group summaries. For venlafaxine Cmax, it estimates a difference of 7.06 ng/mL. Its 95% confidence interval, from -21.38 to 35.5, represents uncertainty in that unadjusted difference under the calculation’s assumptions. The interval includes zero, but this is not evidence that the two products are equivalent. A conventional test for a difference and an equivalence assessment answer different questions: equivalence requires a prespecified range of differences considered acceptably small.

General explanation: a confidence interval gives a range of estimates reasonably compatible with the observed data and the method used to construct the interval. Its width conveys precision; a wider interval indicates more uncertainty about the estimate. The interval is not a range containing a fixed proportion of individual participant values, and it does not state the probability that a particular treatment effect is true.

Why does the crossover structure matter?

In a crossover study, participants receive treatments in sequences, and the comparison can use measurements from the same participant under each treatment. General explanation: paired analyses can account for stable differences between participants and may be more precise than treating treatment groups as independent. The unadjusted recalculation from arm-level means and standard deviations cannot recover the within-participant covariance or the full paired analysis. The registry record does not report the sponsor’s statistical model, sequence and period terms, or treatment of possible carryover, so the details of its crossover analysis cannot be evaluated from the result alone.

The outcome summaries list 22 observations for each product. The primary population description says that participants who completed the study had samples analyzed. The record does not give participant-level data or explain any exclusions, so it is not possible to confirm how the reported counts map to sequences or to assess missingness beyond the posted information.

How should the p-value be read?

The recalculated p-value for the arithmetic mean difference is 0.627. It is an unadjusted result for that comparison under the recalculation, not a p-value from the sponsor’s reported ratio analysis. General explanation: a p-value describes how unusual data at least as incompatible with a specified null model would be if that model were true, given the analysis assumptions. It does not measure the probability that the null hypothesis is true, nor does it establish equivalence. The sponsor-reported analysis has no p-value in the registry record.

The posted recalculation is descriptive and should be distinguished from the trial’s own analysis. The registry does not report the sponsor’s full statistical plan, the original sample-size rationale, the confidence-interval construction details, or formal bioequivalence limits. These omissions restrict independent verification of the formal analysis while leaving the stated estimates and intervals available for statistical interpretation.

11. Confidence Intervals and Precision

The sponsor-reported primary estimate is a test-to-reference geometric-mean ratio of 106.84, with a 90% confidence interval from 100.54 to 113.54. The interval provides a range of values compatible with the estimate under the sponsor’s analysis and indicates uncertainty around the relative comparison. It is centered on a ratio above 100, but its interpretation as evidence for or against bioequivalence depends on acceptance limits that are not reported in the registry record.

The recalculated arithmetic mean difference is 7.06 ng/mL, with a 95% confidence interval from -21.38 to 35.5. This interval is broad relative to the point estimate and includes both negative and positive differences. It therefore allows for uncertainty about whether the test mean is lower or higher on the arithmetic scale. It does not demonstrate equivalence: that requires a defined acceptable range and an analysis designed to assess whether the interval falls within it.

General explanation: confidence intervals convey precision as well as direction. A narrow interval indicates less uncertainty about the estimate than a wide interval, while a wide interval leaves a broader set of plausible values. The sponsor interval and recalculated interval cannot be compared as if they were constructed for the same quantity: they differ in scale, confidence level, and analysis basis. The registry does not report further details needed to assess the interval methods or their assumptions.

The outcome summaries report 22 observations for each product. The modest posted outcome counts and the variability in the group summaries are relevant context for the width of the recalculated interval. The interval is the most direct indication of precision for the estimated mean difference; the p-value alone would not convey the range of effect sizes compatible with the data.

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 sample-size figures are planning illustrations based on the observed effect, not the trial’s own design calculations. For these continuous outcomes, the figures are participants per arm, not total events. The listed assumptions are a two-sided significance level 0.05, equal allocation between the two arms, and a normal approximation; each planning scenario targets the stated fraction of the observed effect. The original design assumptions and sample-size justification are not reported in the registry record.

The 80% power column describes the participant count per arm estimated to give an 80% chance of detecting the specified effect under the planning assumptions, if that effect and the other assumptions hold. The 90% power column uses a higher target chance of detecting that effect and therefore generally calls for more participants per arm. These are planning quantities for a hypothetical study, not a description of the probability that the completed trial detected its effect. This is not observed power.

The rows reduce the assumed effect from 100% of the observed effect to 75% and then 50%. Smaller effects need more participants to distinguish them from random variation under the same planning framework. The displayed values should be read as illustrative scale, not as recommendations or proof that a study of those sizes would be adequate for every design or analysis. In particular, the actual trial used a crossover model, while the stated illustration assumes equal allocation between two arms and a normal approximation; its exact relationship to the original crossover planning is not reported.

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 = 7.060; pooled standard deviation σ = 48.133.
2. n = 2 × (1.96 + 0.842)² × 48.133² / 7.060² = 729.6, rounded up to 730 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 <- 7.06                      # observed difference in means
sigma <- 48.1328006664894                     # 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(1260896)
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 = 730 (80% power), 977 (90% power)
 75% of observed effect: n per arm = 1,298 (80% power), 1,737 (90% power)
 50% of observed effect: n per arm = 2,919 (80% power), 3,908 (90% power)
power.t.test: 730.6 
Simulated power at n = 730 per arm: 0.795 (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. Analyses Reported by the Sponsor

The sponsor’s posted primary analysis reports a test-to-reference geometric-mean ratio of 106.84 and a 90% confidence interval from 100.54 to 113.54. This is the registry’s reported trial analysis for venlafaxine Cmax. It is distinct from the recalculated arithmetic mean difference of 7.06 ng/mL, with a 95% confidence interval from -21.38 to 35.5 and p = 0.627.

The two estimates are not direct duplicates. One is a relative comparison based on geometric means; the other is an unadjusted absolute difference calculated from the posted arithmetic means and standard deviations. The recalculation also cannot use the participant-level pairing that may be relevant in a crossover analysis. It should therefore be read as a supplementary descriptive calculation, not a replacement for the sponsor’s analysis.

The registry labels the sponsor result as an equivalence or non-inferiority type analysis but does not give the method, p-value, or acceptance limits. Without those details, the ratio and interval can be reported and interpreted descriptively, but the formal decision criterion cannot be independently checked. The registry does not indicate a discrepancy between the reported analysis and the recalculation; their differing scales and methods nevertheless mean they address the comparison differently.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary endpoint and several secondary outcomes, but it does not report how multiplicity was handled. In general, testing multiple outcomes can increase the chance of at least one apparently positive result by chance. A prespecified hierarchy, adjustment method, or distinction between confirmatory and exploratory outcomes can help readers understand how much weight to place on multiple findings. None of these procedures is described in the registry record, so it is not possible to determine whether any formal control of multiplicity was planned or applied.

The record identifies the primary analysis population as participants who completed the study and had samples analyzed. The outcome summaries show 22 observations for each product, whereas enrollment is recorded as 24. The registry does not explain the reasons for the difference, the handling of missing measurements, or whether any participants were excluded from particular endpoints. It also does not report an intention-to-treat or per-protocol definition.

Because this is a crossover study, missingness in one treatment period can affect whether a participant contributes a paired comparison. General explanation: the consequences depend on which observations are missing, why they are missing, and the analysis used to handle them. Participant-level flow and reasons for missing data would be needed to assess this. Those details are not reported in the registry record.

The full statistical analysis plan, crossover model, period and sequence handling, and original sample-size justification are also not reported. The sponsor’s reported ratios and confidence intervals remain available, but readers cannot verify all assumptions or reproduce the formal analysis from the registry summary alone.

16. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent non-serious adverse event terms

The serious adverse event summaries list 24 subjects at risk in each sequence group and zero subjects affected by serious adverse events in each group. Death counts are not reported in the registry record. These figures concern serious adverse events, not every adverse event occurring during the study.

The registry separately reports other adverse events for 17 subjects in the Test First group and 14 subjects in the Reference First group, with 24 subjects at risk in each group. These are sequence-group summaries. Because the study is crossover, the same participant may contribute experience under both treatments, and the registry does not provide event-level details or a treatment-period breakdown that would support a direct between-product safety comparison.

The absence of reported serious adverse events in these summaries should be read within the context of a completed study in healthy subjects and the posted observation counts. It does not establish that serious events cannot occur or characterize safety in other populations or settings. The registry record does not list serious-event terms, and it does not provide additional detail about severity, timing, or causality for the other adverse events.

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

The posted data describe pharmacokinetic comparisons between venlafaxine hydrochloride extended-release capsules and Effexor® XR under fasting conditions in healthy subjects. For the primary endpoint, the sponsor reports a test-to-reference geometric-mean ratio of 106.84 with a 90% confidence interval from 100.54 to 113.54. The unadjusted recalculation reports an arithmetic mean difference of 7.06 ng/mL with a 95% confidence interval from -21.38 to 35.5.

These estimates should be understood according to their scales and methods. The ratio is the sponsor’s reported analysis; the mean difference is an unadjusted recalculation that does not use participant-level crossover pairing. Neither should be read as a direct measure of clinical benefit. The registry does not report the equivalence limits needed to determine whether the sponsor’s interval satisfies a formal bioequivalence criterion, so that conclusion cannot be established from the posted information alone.

The findings do not establish how the products compare in patient outcomes, long-term use, or populations other than the healthy subjects studied. They concern measured concentration and exposure endpoints under fasting conditions, not symptom relief or other clinical outcomes. Nor does a non-significant unadjusted p-value establish equivalence; failure to demonstrate a difference and evidence that two treatments are sufficiently similar are different statistical claims.

The posted sample-size illustrations are not a retrospective statement about the chance that this trial detected an effect. They are planning calculations based on the observed effects under stated assumptions. Missing information about the original design rationale, formal analysis plan, missing-data handling, and decision limits places boundaries on what can be concluded from the registry record.

18. Why This Trial Matters Statistically

This trial illustrates why pharmacokinetic comparisons require attention to the estimand and the scale of analysis. The primary sponsor result is a geometric-mean ratio, while the posted arithmetic summaries permit an unadjusted mean-difference calculation. Both can describe the treatment comparison, but they are not interchangeable and need not have the same interpretation.

The crossover design also matters. A crossover can account for within-participant comparisons when the analysis uses paired information, but that information is not recoverable from group means and standard deviations alone. A simple recalculation from those summaries is therefore useful as a descriptive check, but it cannot reproduce a full crossover model. This distinction is especially important when interpreting confidence intervals and p-values derived from a different analysis structure.

The registry’s reporting also demonstrates the importance of decision criteria. A ratio and confidence interval are informative, but a formal equivalence conclusion depends on prespecified limits and an appropriate analysis. Because those limits and the detailed method are not reported, the numerical estimate should not be mistaken for the complete decision process.

Finally, the secondary metabolite endpoints show why multiple outcomes require a clear interpretation plan. Without details on multiplicity or endpoint hierarchy, secondary findings add context but should not be treated as independent confirmatory evidence. The record is useful for identifying the study question and posted estimates, while also showing where fuller protocol and analysis information would be needed for stronger statistical evaluation.

19. 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 registry record does not report the acceptance limits for bioequivalence, the sponsor analysis method, or a full statistical analysis plan. It therefore does not allow an independent assessment of the formal decision rule behind the sponsor-reported ratio and confidence interval. The sponsor result is still the trial’s posted analysis, but its decision context is incomplete.

The simple recalculation is based on arm-level means and standard deviations. It is unadjusted and cannot incorporate the within-participant correlation that may be used in a crossover analysis. It should not be treated as a replication of the sponsor’s method. The record also lacks detail about treatment periods, sequence allocation, washout, and handling of period or carryover effects.

The registry lists 24 enrolled and outcome summaries with 22 observations for each product. It does not explain the participant flow, missing measurements, exclusions, or reasons for the difference in counts. This limits assessment of missing-data bias and the exact analysis population. The original sample-size rationale is not reported; the posted planning illustrations are based on observed effects and are not evidence about the trial’s original design adequacy.

Multiplicity handling for the secondary endpoints is not reported. Safety summaries are presented by treatment sequence rather than with detailed event-level information, and death counts are not reported in the registry record. Finally, the study concerns healthy subjects under fasting conditions and pharmacokinetic endpoints. The record does not support conclusions about clinical outcomes or other populations.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Venlafaxine Hydrochloride 150 mg Extended-Release Capsules Under Fasting Conditions — NCT01260896.
• Registry record last updated 2011-02-21; status last verified 2011-01.
• Results first posted 2011-02-21.
• 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.

23. Record Summary

The registry describes a completed, randomized, unmasked, 2-way crossover Phase 1 study sponsored by Teva Pharmaceuticals USA. It compared venlafaxine hydrochloride 150 mg extended-release capsules with Effexor® XR 150 mg extended-release capsules under fasting conditions in healthy subjects. Enrollment is listed as 24, and outcome summaries report 22 observations for each product.

The primary outcome was venlafaxine Cmax measured from blood samples collected over a 36 hour period. The sponsor reported a test-to-reference geometric-mean ratio of 106.84 with a 90% confidence interval from 100.54 to 113.54. The registry also posts metabolite endpoints and safety summaries. Formal bioequivalence limits, the detailed statistical plan, and reasons for the difference between enrollment and outcome counts are not reported in the registry record.