Two experiments, two development questions
Climate storage and pressure exposure answer different questions. The climate experiment assessed mass change, formulation appearance, applicator condition, and package function. The altitude experiment examined whether reduced pressure produced leakage or measurable package change. Their outcomes should not be merged into a single pass/fail claim.
| Experiment | Units | Conditions | Observation plan | Primary question |
|---|---|---|---|---|
| Climate storage | 210 total; 70 per variant | -30, 5, 23, 40, and 60 °C; study spanning 226 hours | Seven timepoints; immediate and 4-hour room-temperature observations | Mass change, formulation appearance, applicator condition, and package function |
| Simulated altitude | 54 total; 18 per variant | 18,000, 26,000, and 40,000 ft simulated elevation | Immediate and 4-hour room-temperature/pressure observations | Leakage and package behavior under reduced pressure |
The experiments used the same three anonymized variant labels but were not one combined protocol.
Climate-storage design
The climate experiment included 210 units: 70 per anonymized variant, with 14 per variant at each of -30 °C, 5 °C, 23 °C, 40 °C, and 60 °C. The study spanned 226 hours. At seven observation points, two units per variant and condition were removed. One was evaluated immediately; the other was evaluated after four hours at room temperature.
The study spanned 226 hours, but individual units had different exposure durations because they were removed at successive observation points. The immediate and four-hour evaluations used separate units, so they show package appearance under each evaluation condition without demonstrating recovery of the same package between inspections. The total sample count therefore does not represent repeated measurements on every package.
Units were weighed before and after exposure and inspected for residue, internal appearance, cap and wand behavior, brush appearance, product accumulation, crystallization, and wiper seating. The qualitative accumulation scale was intentionally strict, so a slight level-1 observation did not necessarily represent an unacceptable condition.
Climate-storage results
View figure data as a table
| temperature | Variant A | Variant B | Variant C |
|---|---|---|---|
| -30 °C | 0 mg | 0 mg | 0 mg |
| 5 °C | 0 mg | 0 mg | 0 mg |
| 23 °C | 15 mg | 15 mg | 15 mg |
| 40 °C | 93 mg | 52 mg | 51 mg |
| 60 °C | 88 mg | 95 mg | 90 mg |
Values summarize the climate-storage experiment.
- The 40 °C Variant A bar includes one anomalous 93 mg result; the maximum among the remaining Variant A units was 46 mg.
- The report did not determine the cause of elevated-temperature mass loss.
| Temperature | Units across variants | Variant A | Variant B | Variant C | Observed package/formulation condition |
|---|---|---|---|---|---|
| -30 °C | 42 | 0 mg | 0 mg | 0 mg | Frozen immediately after removal; thawed after four hours |
| 5 °C | 42 | 0 mg | 0 mg | 0 mg | Generally normal; occasional slight accumulation |
| 23 °C | 42 | 15 mg | 15 mg | 15 mg | Weight loss observed; occasional accumulation |
| 40 °C | 42 | 93 mg (46 mg among remaining units) | 52 mg | 51 mg | More visible accumulation; a pre-existing residue condition dried or crystallized |
| 60 °C | 42 | 88 mg | 95 mg | 90 mg | All 42 wands bent; all wipers displaced or stuck during opening |
The 93 mg result came from one anomalous Variant A unit. The maximum among the other Variant A units at 40 °C was 46 mg. Cause of mass loss was not determined.
Three abnormalities were documented before climate exposure. One Variant A unit was recorded as having an internal leak, and another Variant A unit had serum on the exterior, thread, and wand. One Variant C unit was difficult to open. The unit later photographed with dried or crystallized thread residue at 40 °C already had residue before exposure. That image therefore does not establish a new storage-caused leak.
The weight-loss display reports maxima, not group means or the fraction of units affected. At 23 °C, each variant had a maximum of 15 mg. At 60 °C, the maxima were 88, 95, and 90 mg for A, B, and C. These maxima do not show that every unit lost that amount or establish a precise temperature threshold for the package.
Maximum measured loss was 0 mg at -30 °C and 5 °C, but the immediately inspected -30 °C samples were frozen. Separate observations after four hours at room temperature recorded thawing. A zero in the weight-loss table means that this measurement recorded no mass loss under those conditions. It does not mean the product had no visible or functional change during cold exposure; the inspections describe its observed state.
The report discussed possible mechanisms for elevated-temperature mass loss, but the measurements did not establish a cause.
At 40 °C, the 93 mg result came from one unusual Variant A unit; the maximum among the remaining Variant A units was 46 mg. Both values are reported to keep that distinction clear. The pre-exposure residue observation also matters: the later photograph documents the residue's appearance but does not establish when or why it first developed.
Altitude-exposure design
The altitude experiment included 54 units: 18 per variant, with six per variant exposed at each simulated elevation. For each variant/elevation combination, three units were inspected immediately and three after four hours at room temperature and pressure. Samples were held close to horizontal in a sealed chamber for 15 minutes at the target condition.
| Simulated altitude | Equivalent absolute pressure | Gauge vacuum | Ramp | Dwell | Units |
|---|---|---|---|---|---|
| 18,000 ft | 7.6 psi | -15.0 in Hg | 9 min | 15 min | 18 |
| 26,000 ft | 5.2 psi | -19.5 in Hg | 13 min | 15 min | 18 |
| 40,000 ft | 2.7 psi | -24.5 in Hg | 20 min | 15 min | 18 |
| Variant | 18,000 ft | 26,000 ft | 40,000 ft |
|---|---|---|---|
| A | 0.167 ± 0.408 mg | 0.333 ± 0.516 mg | 0.833 ± 0.753 mg |
| B | 0.667 ± 0.816 mg | 0.333 ± 0.516 mg | 0.500 ± 0.548 mg |
| C | 0.500 ± 0.548 mg | 0.667 ± 0.516 mg | 0.833 ± 0.753 mg |
The report recorded no observed exterior or cap-thread leakage. An internal-visual inconsistency between summary and inspection sheets remains disclosed in the article.
What the altitude results support
The report recorded no observed exterior or cap-thread leakage at either post-exposure time. Mean weight changes were below 1 mg for every variant/elevation combination. The internal-visual records conflict: individual inspection sheets marked the bottom viewing window as cloudy throughout, while the summary reports a moving or visible bubble. This inconsistency limits the conclusion to the supported leakage and inspection findings. The records do not support an unqualified statement that every internal-visual observation agreed.
The altitude table reports mean weight change and sample standard deviation for six units per variant and elevation. A mean below 1 mg summarizes the group; it does not mean every individual result was identical. The no-observed-leak result also does not resolve the conflicting internal-visual records. Leakage, measured mass change, and internal appearance are separate observations, each with its own limits.
Development interpretation
For this anonymized product-package configuration, elevated temperature produced more pronounced package-function findings than the tested reduced-pressure exposures. The main finding involved the applicator system: at 60 °C, wand deformation coincided with wiper displacement during opening.
High-temperature inspection identified a wand-and-wiper issue to investigate without establishing its cause. The altitude experiment provided a no-observed-leak result within the tested conditions. Neither experiment identifies a final redesign, verifies a corrective action, or establishes a shelf life. Those decisions require their own acceptance criteria and follow-up evidence; the displayed summary values alone cannot establish them.
Summary
The two experiments gave the client a comparison of package behavior under the tested temperature and reduced-pressure conditions. ARE Labs documented the observed mass changes and package-function findings, including the anomaly and conflicting visual records. These results could inform the next package review without establishing a failure mechanism or performance beyond the tested conditions.