USP <671>
USP <671> evaluates how well packaging protects pharmaceutical products from moisture. The main focus is measuring the moisture vapor transmission rate (MVTR), how much water vapor can pass through a package over time. This is critical because too much moisture can degrade drug products. The standard provides test methods (often using desiccants and controlled humidity conditions) to generate measurable data on package performance.
USP <671> establishes classification systems for different types of packaging, helping determine whether a package is “tight,” “well-closed,” or falls into barrier categories (ie: high vs. low moisture protection). Overall, USP <671> helps manufacturers select and validate packaging systems that maintain product stability and quality throughout shelf life.
USP 671 Moisture Vapor Transmission Rate
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Method 1 – Multiple-Unit Containers (Barrier Determination)
Measures moisture vapor transmission for bottles and similar containers using desiccant-filled systems over time, providing a quantitative MVTR value to compare barrier performance.
Method 2 – High-Barrier Blister Packs
Evaluates moisture protection of high-barrier blister packaging by tracking weight gain under controlled conditions, allowing precise comparison of very low moisture transmission rates.
Method 3 – Low-Barrier Blister Packs
Assesses moisture transmission in low-barrier blister systems using a shorter test duration, where desiccant saturation occurs more quickly, and results are calculated over a 2-day period.
Method 5 – Multiple-Unit Container Classification – Solid Oral Dosage Form (SODF)
Classifies bottles and similar packaging as “tight” or “well-closed” based on moisture gain over time, helping determine if the packaging is suitable for protecting solid oral products.
Method 6 – Plastic Container Material Performance
Evaluates moisture barrier performance specifically for plastic packages with an impervious seal, helping determine if the packaging is suitable for protecting solid oral products.
Method 7 – Unit-Dose Container Classification (SODF)
Classifies single-unit and blister packaging (ie: classes A – D) based on moisture vapor transmission, helping determine the level of protection provided to individual doses.
Method 8 – Liquid Oral Container Testing (LODF)
Measures weight loss from filled liquid containers over time to assess how well packaging prevents evaporation and maintains product integrity.
Frequently asked questions
How does PCL calculate MVTR?
PCL performs all measurements on a calibrated analytical scale and uses validated calculators. Everything else is specific to the method used.
Do I need USP <671> testing for my product?
You may need testing if you are launching a new product, changing packaging materials or suppliers, repackaging products, or supporting stability and regulatory submissions.
What is moisture vapor transmission rate (MVTR)?
MVTR measures how much moisture passes through a packaging system over time. It is a key indicator of how well packaging protects moisture-sensitive products.
How do I know which test method applies to my packaging?
The appropriate method depends on your packaging type (ie: bottle vs. blister) and barrier level.
How long does MVTR testing take?
Most MVTR/USP <671> tests run between a few days to several weeks, depending on the method and barrier properties of the packaging.