SOP-001: Real-Time Stability Testing

1. Purpose

This procedure establishes the protocol for conducting real-time stability testing on cosmetic emulsions under ambient storage conditions. Real-time testing validates the labeled shelf life by monitoring product changes over the actual intended storage period.

2. Scope

This SOP applies to all finished cosmetic products including lotions, creams, serums, and other emulsion-based formulations requiring shelf life validation.

3. Storage Conditions

Temperature: 20-25°C (68-77°F)
Humidity: Ambient (40-60% RH typical)
Light: Protected from direct light unless product is designed for light exposure
Container: Final market packaging, stored upright unless otherwise specified

4. Sample Requirements

Minimum 3 units per batch for testing
Additional units as retention samples
All samples from same production batch
Samples must be properly labeled with batch number, manufacturing date, and sample ID

5. Evaluation Schedule

Timepoint	Duration from T0	Tests Performed
T0 (Initial)	Day 0	All parameters
T1	1 Month	All parameters
T2	3 Months	All parameters
T3	6 Months	All parameters
T4	12 Months	All parameters
T5	18 Months	All parameters
T6	24 Months	All parameters

6. Evaluation Parameters

6.1 Visual Appearance

Observe for: phase separation, creaming, sedimentation, color change, clarity/opacity changes, surface film

6.2 Odor

Evaluate for: off-notes, rancidity, chemical/preservative smell, fragrance degradation

6.3 pH Measurement

Measure using calibrated pH meter. Document deviation from initial pH. Flag if drift exceeds ±0.5 units.

6.4 Viscosity

Measure using appropriate viscometer at standard temperature (25°C). Note significant changes (>10% deviation).

6.5 Texture/Feel

Evaluate spreadability, grittiness, stickiness, skin feel compared to initial sample.

7. Pass/Fail Criteria

Parameter	Pass Criteria	Fail Criteria
Appearance	No visible separation or significant change	Phase separation, creaming, syneresis
Color	Consistent with initial (minor fading acceptable)	Significant color change, yellowing, browning
Odor	Consistent fragrance profile	Off-notes, rancidity, unpleasant smell
pH	Within ±0.5 of initial	Drift >0.5 units from initial
Viscosity	Within ±15% of initial	Change >15% from initial

Product Name:
Batch/Lot Number:
Manufacturing Date:
Test Start Date (T0):
Target Shelf Life:
Storage Location:
Preservative System:

Timepoint	Date	Appearance	Color	Odor	pH	Viscosity	Pass/Fail	Initials
Initial (T0)
1 Month
3 Months
6 Months
12 Months
18 Months
24 Months