This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Comparison of the Bioavailability of Diclofenac in a Combination Product (Diclofenac 2% + Capsaicin 0.075% Topical Gel) With Two Diclofenac Only Products, Diclofenac Mono Gel 2% and Voltarol® 12 Hour Emulgel 2.32% Gel, in Healthy Volunteers (NCT03074162), a randomized phase 1 study. The primary outcome is Area Under the Plasma Concentration-time Curve (AUC) Over One Dosing Interval for Diclofenac at Steady State (AUC0-τ,ss) (τ = 12 Hours) (Day 7).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03074162 |
| Phase | Phase 1 |
| Condition | Healthy |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | None (open label) |
| Enrollment | 48 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Boehringer Ingelheim |
| Results posted | Yes |
2. Clinical Question
Population
Healthy male and female volunteers. The study title specifies at least 42 participants, and the registry record reports enrollment of 48. The study summary says the population was to be stratified 50:50 by Caucasian and Black race to examine potential racial differences in pharmacokinetics.
Intervention
Topical combination gel containing diclofenac 2% and capsaicin 0.075%. The stated objective was to assess the relative systemic bioavailability of diclofenac in the presence of capsaicin.
Comparator
Two diclofenac-only products: Diclofenac Mono Gel 2% and Voltarol® 12 Hour Emulgel 2.32% Gel. The registry record identifies the comparator products, but does not give detailed administration instructions in the available record.
Primary question
At steady state on Day 7, how does diclofenac exposure over a 12-hour dosing interval, measured by AUC0-τ,ss, compare across the combination gel and the diclofenac-only products? The registry record describes this objective but does not report the numerical primary endpoint results.
This is a pharmacokinetic comparison, not a clinical-outcome trial. Its primary question concerns the amount of diclofenac measured in plasma over a dosing interval after repeated topical administration. In general, systemic bioavailability describes how much of a drug reaches the systemic circulation, and a relative comparison asks how that exposure differs between formulations. The presence of capsaicin is part of the formulation contrast; the comparison is not an isolated test of capsaicin under otherwise identical conditions unless the products and their use make that contrast valid. The registry record does not report enough product-use detail to assess that issue.
The record also describes an exploratory-supportive interest in whether race influences within-person bioavailability ratios. Race-stratified estimates were to be obtained through an Analysis of Variance, with treatment comparisons considered within race. The actual race-specific estimates and results are not reported in the registry record. Thus the registry entries establish the intended population, formulations, and exposure question, but not the direction or precision of any observed difference.
3. Trial Design
The registry identifies this as a Phase 1, randomized, open-label, single-center, multiple-dose, three-period crossover study. It was conducted in healthy volunteers, and the status is completed. The registry reports enrollment of 48. The record gives a start date of 2017-04-20 and a primary completion date of 2017-06-29.
In a crossover study, participants receive more than one treatment across different periods, so treatment comparisons can be made within participants. In general, this can reduce the influence of stable between-person differences in drug exposure, because each participant can contribute observations under multiple formulations. It also means that the order of treatments, period effects, and possible carryover need to be considered in the analysis. The record identifies randomization and a three-period crossover, but the treatment sequences, washout arrangements, and period-specific procedures are not reported in the registry record.
The study was open-label, meaning masking was not used. The registry lists three products: Diclofenac Mono Gel 2%, the diclofenac 2% plus capsaicin 0.075% combination gel, and Voltarol® 12 Hour Emulgel 2.32% Gel. It does not give full arm-level administration instructions or a detailed account of how treatment periods were implemented. These details should not be inferred from the product names alone.
The objective was relative systemic bioavailability, with pharmacokinetic sampling on Day 7 at pre-dose and 0.5, 1, 2, 3, 4, 6, 8, 10 and 12 hours after administration. The record describes planned supportive analyses by race. Although the title specifies at least 42 healthy males and females, the registry's enrollment figure is 48; enrollment does not by itself establish how many participants contributed usable data to each analysis. The numbers analyzed by treatment and race are 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: All subjects were screened for eligibility to participate in the trial. Subjects attended the trial site and it was ensured that they met all strictly implemented inclusion/exclusion criteria. Subjects were not to be randomised to trial treatment if any one of the specific entry criteria were violated.
Period 1 Including Washout 1
| Stage | A-B-R | B-R-A | R-A-B | R-B-A | A-R-B | B-A-R |
|---|---|---|---|---|---|---|
| STARTED | 8 | 8 | 8 | 8 | 8 | 8 |
| COMPLETED | 8 | 8 | 7 | 8 | 8 | 8 |
| NOT COMPLETED | 0 | 0 | 1 | 0 | 0 | 0 |
Reasons for not completing this period:
| Reason | A-B-R | B-R-A | R-A-B | R-B-A | A-R-B | B-A-R |
|---|---|---|---|---|---|---|
| Withdrawal by Subject | 0 | 0 | 1 | 0 | 0 | 0 |
Period 2 Including Washout 2
| Stage | A-B-R | B-R-A | R-A-B | R-B-A | A-R-B | B-A-R |
|---|---|---|---|---|---|---|
| STARTED | 8 | 8 | 7 | 8 | 8 | 8 |
| COMPLETED | 8 | 8 | 6 | 8 | 8 | 7 |
| NOT COMPLETED | 0 | 0 | 1 | 0 | 0 | 1 |
Reasons for not completing this period:
| Reason | A-B-R | B-R-A | R-A-B | R-B-A | A-R-B | B-A-R |
|---|---|---|---|---|---|---|
| Withdrawal by Subject | 0 | 0 | 1 | 0 | 0 | 1 |
Period 3
| Stage | A-B-R | B-R-A | R-A-B | R-B-A | A-R-B | B-A-R |
|---|---|---|---|---|---|---|
| STARTED | 8 | 8 | 6 | 8 | 8 | 7 |
| COMPLETED | 7 | 8 | 6 | 8 | 7 | 7 |
| NOT COMPLETED | 1 | 0 | 0 | 0 | 1 | 0 |
Reasons for not completing this period:
| Reason | A-B-R | B-R-A | R-A-B | R-B-A | A-R-B | B-A-R |
|---|---|---|---|---|---|---|
| Withdrawal by Subject | 1 | 0 | 0 | 0 | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: Pharmacokinetic Population (PK): This population consists of all subjects in the safety population for whom at least one of area under the plasma concentration-time curve over one dosing interval or maximum steady-state plasma drug concentration during a dosage interval could be calculated for one treatment and who had no major protocol deviations.
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.
Population: Safety Population: All subjects who received at least one dose of investigational medicinal product (IMP) were included in the safety analysis of the study.
Only the first 6 of 7 groups are shown.
| Characteristic | Unit | A-B-R | B-R-A | R-A-B | R-B-A | A-R-B | B-A-R |
|---|---|---|---|---|---|---|---|
| Participants analysed | 8 | 8 | 8 | 8 | 8 | 8 | |
| Age, Continuous | Years | 30.9 (SD 9.43) | 29.4 (SD 10.04) | 27.6 (SD 7.84) | 28.5 (SD 8.82) | 22.5 (SD 3.38) | 26.0 (SD 8.16) |
| Sex: Female, Male: Female | Participants | 1 | 2 | 4 | 3 | 1 | 3 |
| Sex: Female, Male: Male | Participants | 7 | 6 | 4 | 5 | 7 | 5 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 4 | 4 | 4 | 4 | 4 | 4 |
| Race (NIH/OMB): White | Participants | 4 | 4 | 4 | 4 | 4 | 4 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Area Under the Plasma Concentration-time Curve (AUC) Over One Dosing Interval for Diclofenac at Steady State (AUC0-τ,ss) (τ = 12 Hours) (Day 7), measured over Pharmacokinetic samples were collected on Day 7 at pre-dose and 0.5, 1, 2, 3, 4, 6, 8, 10 and 12 hours after the drug administration.
| Element | Registry entry |
|---|---|
| Result type | Geometric Mean |
| Measure of spread | Geometric Coefficient of Variation |
| Unit | Hour*nanogram/millilitre (h*ng/mL) |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the area under the plasma concentration-time curve over one dosing interval at steady state for diclofenac, abbreviated AUC0-τ,ss, with τ defined as 12 hours. Measurements were collected on Day 7, after multiple-dose administration. The endpoint is expressed in hour*nanogram/millilitre (h*ng/mL), and the registry specifies that the reported summary measure is the geometric mean, with geometric coefficient of variation as the dispersion measure.
In general, an area under the concentration-time curve represents drug exposure across the sampled interval: it combines concentration information over time rather than describing a single blood sample. For a formulation comparison, this makes AUC useful for assessing relative systemic exposure over the dosing interval. A steady-state measurement is intended to characterize exposure when repeated dosing has reached a steady pattern, as defined by the study's pharmacokinetic framework. The record does not report the concentrations or endpoint estimates, so the actual exposure levels and differences cannot be described.
Geometric means are commonly used for pharmacokinetic measurements when values are positively skewed or comparisons are naturally expressed on a multiplicative scale. The geometric coefficient of variation describes relative variability around that geometric summary. In general, it is not interchangeable with a standard deviation on the original scale. Neither the estimates nor their uncertainty are reported in the registry record, so the precision of the endpoint comparison cannot be assessed from the posted results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the design and the intended primary comparison, but it does not report numerical AUC0-τ,ss results. It gives no geometric means by treatment, treatment ratios, confidence intervals, p-values, or other estimates of uncertainty for the primary endpoint. Consequently, the posted information does not establish which product produced greater or lesser measured diclofenac exposure, how large any difference was, or how precisely a difference was estimated.
The study's objective is to compare systemic bioavailability for diclofenac from the combination gel with bioavailability from two diclofenac-only products. That objective should not be mistaken for a reported finding. The product concentrations differ, and one comparator is a different formulation and strength from the other. The record therefore describes a comparison among products, not a result that can be attributed solely to the presence or absence of capsaicin. The registry does not report enough formulation-use detail to interpret product-level differences beyond the stated objective.
The crossover design is relevant to interpretation because within-participant measurements can support paired comparisons. In general, this can make estimates less dependent on between-person variability than a parallel-group comparison. However, the result still depends on the analysis population, completeness of measurements, period and sequence handling, and any assumptions about carryover. The relevant protocol and detailed analysis information are not reported in the registry record. It is therefore not possible to judge whether those design features were adequately addressed.
The record says race-stratified supportive analysis was conducted using an Analysis of Variance, producing point estimates for pairwise comparisons. It also says only geometric means by treatment and race are presented because least-squares means and geometric means were very similar. But the actual values are absent from the registry entries. No conclusion about racial differences, consistency across racial groups, or uncertainty within either group can be drawn.
Completion status and enrollment describe the conduct of the trial, not the result of its pharmacokinetic comparison. Likewise, the absence of numerical efficacy-style estimates in this record is not evidence that the products had identical exposure. The defensible reading is that a randomized crossover study was designed to compare steady-state diclofenac exposure, while the registry record available for interpretation does not report the estimates needed to characterize the observed comparison.
9. Statistical Methods Explained
The registry describes a randomized, open-label, three-period crossover design with multiple dosing. These features determine what the statistical comparison is intended to represent. Randomization assigns treatment order rather than masking treatment identity; open-label status means treatment allocation was not concealed from participants or investigators through blinding, according to the record. The sequence-generation method and allocation details are not reported in the registry record.
Why use a crossover design?
In general, a crossover study compares treatments within the same participant across separate periods. A participant's measurements under different products can therefore be compared with that participant's own measurements, which may control some stable individual differences in drug exposure. This is particularly relevant to pharmacokinetic outcomes, which can vary between people. The design relies on appropriate period conduct and analysis: treatment order, period effects, and carryover may affect measurements. Washout duration, period schedules, and the method used to address these issues are not reported in the registry record.
What does the primary measure summarize?
AUC0-τ,ss is the area under the plasma concentration-time curve over one dosing interval at steady state. Here, τ is 12 hours, and the endpoint is assessed on Day 7. The registry lists sampling at pre-dose and 0.5, 1, 2, 3, 4, 6, 8, 10 and 12 hours after administration. In general, integrating concentrations over time summarizes exposure across the interval rather than relying on a single time point. The record does not explain the specific computational method used to derive each participant's AUC.
The stated summary statistic is the geometric mean, with geometric coefficient of variation. In general, pharmacokinetic data are often analyzed on a logarithmic scale because exposure values may be skewed and treatment contrasts may be multiplicative. Back-transformation can express a comparison as a ratio of geometric means. That is a general explanation of common practice, not a claim about unreported details of this trial's main model. The registry record does not provide the actual estimates, their confidence intervals, or a complete description of the primary statistical model.
How was race considered?
The study summary says the population was to be stratified 50:50, Caucasian versus Black, to examine potential racial differences in pharmacokinetics. It describes a supportive Analysis of Variance for race-stratified comparisons, with point estimates for pairwise comparisons. The description notes that least-squares means and geometric means per treatment and race were very similar and says only geometric means per treatment and race are presented. The actual race-specific values are not reported in the registry record. The exact model terms, interaction assessment, and uncertainty estimates are also not reported.
What can be said about statistical precision?
A confidence interval, in general, expresses the uncertainty around an estimated treatment contrast under the assumptions of the analysis. A narrow interval would indicate greater precision than a wide interval, while the interval's location would help assess the range of effects compatible with the data. No confidence intervals are included in the registry entries, so precision cannot be evaluated. No p-values or hypothesis-test results are reported either. It is not appropriate to infer statistical significance or equivalence from the study design or from the absence of a reported result.
The record identifies a pharmacokinetic population as the population for the primary outcome, but the description is incomplete: it refers to subjects in the safety population for whom at least one of specified pharmacokinetic measures could be calculated, and then ends before the eligibility wording is complete. The full definition, participant counts in each analysis, and handling of incomplete measurements are not reported in the registry record. The statistical model and any prespecified criteria for interpreting relative bioavailability are also not reported.
In general, over-dispersion means that observed variability is greater than a model would expect under its assumptions. For pharmacokinetic outcomes, substantial variability can widen uncertainty and reduce precision. This is a general concept; the registry record does not report a dispersion assessment beyond naming geometric coefficient of variation as the endpoint's variability measure. It gives no numerical variability estimates with which to assess the degree of dispersion in this study.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies a primary pharmacokinetic outcome and lists secondary outcomes involving time to maximum observed plasma concentration at steady state, average plasma concentration at steady state, and percentage peak-trough fluctuation. It also describes supportive race-stratified analyses. These multiple outcomes and comparisons create a general multiplicity issue: the more statistical questions assessed, the greater the chance that some results may appear noteworthy by chance if each is interpreted separately. The record does not report a multiplicity adjustment, a hierarchy among secondary analyses, or a prespecified strategy for controlling error across comparisons. Whether such procedures were specified elsewhere is not reported in the registry record.
Missing-data handling is also not described. The record gives a pharmacokinetic population definition, but its wording is incomplete, and it does not state how missing samples, incomplete concentration profiles, or unavailable AUC measurements were handled. The number of participants with usable results for each treatment comparison is not reported. Enrollment of 48 should not be treated as the analysis count for every endpoint.
The registry lists a completed study and reports safety counts by treatment group, but these registry entries do not establish completeness of the pharmacokinetic dataset. It does not report exclusions, withdrawals, protocol deviations, or reasons that measurements may have been unavailable. There is no information about imputation or sensitivity analyses for missing pharmacokinetic values. These omissions limit assessment of whether the analyzed participants represent the enrolled group and whether missingness could influence the comparisons.
The complete statistical analysis plan, including any prespecified primary contrasts, significance criteria, and treatment of multiplicity or missing data, is not reported in the registry record. As a result, the available information supports description of the intended methods but not a full appraisal of the analysis decisions.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Diclofenac 2% (A) | 0 | 47 | 0.0% |
| Diclofenac 2% + Capsaicin 0.075% (B) | 0 | 46 | 0.0% |
| Voltarol® 2.32% Gel (R) | 0 | 47 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Diclofenac 2% (A) | 0 of 47 |
| Diclofenac 2% + Capsaicin 0.075% (B) | 0 of 46 |
| Voltarol® 2.32% Gel (R) | 0 of 47 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Diclofenac 2% (A) | 9 of 47 |
| Diclofenac 2% + Capsaicin 0.075% (B) | 44 of 46 |
| Voltarol® 2.32% Gel (R) | 3 of 47 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Diclofenac 2% (A) | Diclofenac 2% + Capsaicin 0.075% (B) | Voltarol® 2.32% Gel (R) |
|---|---|---|---|---|
| Application site inflammation | General disorders | 2 of 47 | 44 of 46 | 0 of 47 |
| Application site pruritus | General disorders | 6 of 47 | 3 of 46 | 2 of 47 |
| Application site dryness | General disorders | 2 of 47 | 3 of 46 | 0 of 47 |
| Application site erythema | General disorders | 3 of 47 | 0 of 46 | 0 of 47 |
| Viral upper respiratory tract infection | Infections and infestations | 0 of 47 | 3 of 46 | 0 of 47 |
| Headache | Nervous system disorders | 0 of 47 | 0 of 46 | 3 of 47 |
The registry reports zero serious adverse events in each of the three treatment groups. It reports zero deaths in each group. For other adverse events, the record gives 9 among 47 at risk for Diclofenac 2% (A), 44 among 46 at risk for Diclofenac 2% + Capsaicin 0.075% (B), and 3 among 47 at risk for Voltarol® 2.32% Gel (R). These are the posted counts and denominators; they should be read as group-specific registry figures, not as a comparative analysis.
The record does not provide event terms, severity classifications for the other events, timing, duration, or a causal assessment for these counts. It also does not report statistical comparisons of adverse-event frequency between groups. The serious-event count of zero means no serious adverse events are reported in these group entries; it does not establish that no safety events of any kind occurred. The other-event counts are not a measure of severity, and the record does not explain whether participants could contribute more than one event. No overall safety conclusion can be inferred from these figures alone.
In general, adverse-event counts need context about definitions, ascertainment, exposure, and participant-level event rules. The registry record does not report enough detail to assess those features or to determine whether differences in the counts reflect treatment, reporting, or other factors.
12. What the Result Does, and Does Not, Mean
This trial addresses a focused pharmacokinetic question: whether systemic diclofenac exposure at steady state differs across a diclofenac–capsaicin combination gel and two diclofenac-only topical products. The registry identifies AUC0-τ,ss over a 12-hour dosing interval on Day 7 as the primary endpoint. It describes randomized treatment order, repeated dosing, and a crossover structure in healthy volunteers. These details explain the intended comparison, but they do not supply the numerical result.
The posted record does not report treatment-specific AUC estimates, ratios, confidence intervals, or p-values. It therefore cannot establish the magnitude, direction, or precision of any exposure difference. A missing numerical result should not be interpreted as evidence of no difference, equivalence, or a particular product ranking. Those conclusions require estimates and an analysis framework that are not present in the registry record.
Even with numerical pharmacokinetic results, systemic exposure would not by itself answer every clinical question. In general, a plasma exposure measure is not the same as symptom improvement, local tissue exposure, or the overall balance of benefits and harms. This study enrolled healthy volunteers, and the record does not report clinical efficacy outcomes. It should therefore be understood as a formulation bioavailability study rather than evidence about clinical outcomes in people being treated for a condition.
The treatment comparison also involves named products with different stated strengths and formulations. Any observed product-level contrast would not automatically isolate capsaicin as the cause of a difference. The registry's intended focus is diclofenac bioavailability in the presence and absence of capsaicin, but the available record does not provide detailed formulation and use information sufficient to assess how narrowly that contrast can be interpreted.
The supportive analysis by race is described as an investigation of possible differences in within-person bioavailability ratios. Without the race-specific estimates and their uncertainty, neither a difference nor similarity between racial groups can be concluded. The study's stated stratification does not substitute for reported results. Overall, the record explains what the investigators aimed to compare, while leaving the central numerical findings and their statistical precision unreported.
13. Why This Trial Matters Statistically
This study is statistically interesting because topical formulations can be compared through measured systemic drug exposure rather than through a clinical endpoint alone. AUC0-τ,ss captures diclofenac concentration over a dosing interval at steady state, making the endpoint relevant to the stated relative-bioavailability objective. The record also reports a sampling schedule across the interval and identifies a geometric-mean summary, both of which clarify the intended pharmacokinetic description.
The crossover structure is another important feature. In general, within-participant comparisons can help separate treatment contrasts from stable differences among participants. That advantage comes with design and analysis requirements: order and period effects need consideration, and carryover must be addressed where relevant. The registry identifies the crossover but does not report the details needed to evaluate those parts of the design.
The race-stratified supportive analysis is also notable because the study summary explicitly identifies potential racial differences in pharmacokinetics as an interest. It describes a planned 50:50 stratification and an Analysis of Variance approach for supportive comparisons. However, the actual estimates and uncertainty are not reported in the registry record, so the statistical question is visible but its answer is not.
Most importantly, the record illustrates the distinction between a well-defined endpoint and an interpretable result. Knowing the endpoint, design, and stated summary statistic does not reveal the estimated treatment contrast. Without treatment-specific results and uncertainty, readers cannot judge the size or precision of the observed association. This matters in pharmacokinetic work, where an estimate's scale and uncertainty are central to interpretation.
Finally, the registry's safety counts show why descriptive event reporting should be distinguished from a comparative safety analysis. Counts by group do not, on their own, establish causality or quantify a treatment effect. The record supports a careful description of study design and reported events, but not a broad conclusion about clinical benefit or safety.
14. 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 principal limitation for interpreting the pharmacokinetic comparison is that the registry record does not report the primary endpoint estimates. Geometric means, treatment contrasts, confidence intervals, and p-values are absent. The actual size and precision of any difference therefore cannot be assessed. The record also does not report the secondary outcome estimates, despite listing several secondary pharmacokinetic measures.
Important design details are not available. Although the study is described as a randomized, open-label, three-period crossover, the treatment sequences, period arrangements, washout procedures, and analysis of period or carryover effects are not reported in the registry record. The exact administration instructions are also not reported. These omissions make it difficult to evaluate how well the crossover design supports the intended contrasts.
The analysis description is incomplete. The primary outcome population definition ends mid-description, and the number analyzed for each treatment or race subgroup is not reported. Handling of missing samples, exclusions, and protocol deviations is not reported. The full statistical model and any prespecified decision criteria for interpreting relative bioavailability are not reported either.
Race was a stated supportive interest, but no race-specific estimates or uncertainty are included in the registry entries. The planned stratification does not establish the achieved composition of the analyzed population. The record also does not report detail about the adverse events beyond group counts and serious-event and death counts; event terms, severity, timing, and attribution are not provided.
Finally, the study was conducted in healthy volunteers and focused on pharmacokinetic outcomes. The registry record does not report clinical efficacy outcomes. The findings, even if numerical exposure results were available, would address systemic drug exposure rather than directly establish clinical outcomes. The absent results and limited methodological detail restrict interpretation to the stated design and objectives.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Comparison of the Bioavailability of Diclofenac in a Combination Product (Diclofenac 2% + Capsaicin 0.075% Topical Gel) With Two Diclofenac Only Products, Diclofenac Mono Gel 2% and Voltarol® 12 Hour Emulgel 2.32% Gel, in Healthy Volunteers — NCT03074162.
- Registry record last updated 2019-03-01; status last verified 2019-02.
- Results first posted 2019-03-01.
- 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.
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18. Record Summary
NCT03074162 is a completed Phase 1, randomized, open-label, single-center, multiple-dose, three-period crossover study sponsored by Boehringer Ingelheim. It enrolled 48 healthy volunteers and compared diclofenac exposure from a diclofenac 2% plus capsaicin 0.075% topical gel with Diclofenac Mono Gel 2% and Voltarol® 12 Hour Emulgel 2.32% Gel.
The primary endpoint was AUC0-τ,ss for diclofenac over a 12-hour dosing interval on Day 7, summarized by geometric mean with geometric coefficient of variation. Pharmacokinetic samples were scheduled from pre-dose through 12 hours after administration. The record describes supportive race-stratified analyses and lists secondary pharmacokinetic outcomes.
The registry reports adverse-event group counts, including zero serious adverse events and zero deaths in each group. It does not report numerical primary endpoint results, treatment contrasts, confidence intervals, or p-values. Detailed missing-data handling and the complete statistical analysis plan are not reported in the registry record.