2.2.5 | European Pharmacopoeia

A pycnometer is a glass flask with a close-fitting stopper that has a capillary hole running through it. This design ensures that the volume of liquid held by the flask is constant.

: When determining density by weighing, the buoyancy of air is generally disregarded unless a more precise calculation is required, which may introduce a small error of approximately 1 unit in the fourth decimal place.

The 2024-2025 editions of the European Pharmacopoeia continue to emphasize harmonization with ICH Q4B. Expect:

Key nuance: Relative density is a dimensionless quantity. It is not the same as absolute density (mass/volume), because it compares the substance to a reference standard—purified water with a known density at specified temperatures. european pharmacopoeia 2.2.5

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may be used if measurement at exactly 20 °C is impractical, but the monograph prefers actual temperature control.

European Pharmacopoeia 2.2.5. Relative Density - Anton Paar Wiki A pycnometer is a glass flask with a

For global compliance, a laboratory testing products for EU markets must strictly follow Ph. Eur. 2.2.5, not USP <841>.

. In pharmaceutical testing, the standard reference temperatures are typically for both the substance and water, expressed as d2020d sub 20 to the 20th power Analytical Methods

Accurate relative density testing is mandatory for several reasons: : may be used if measurement at exactly

Each monograph referencing Ph. Eur. 2.2.5 provides an acceptable range. For example:

In the intricate world of pharmaceutical manufacturing, the difference between a life-saving medicine and a hazardous substance often comes down to minute details. Among the myriad of tests required to ensure the quality, safety, and efficacy of medicinal products, physical parameters serve as the first line of defense. One of the most fundamental, yet critical, of these parameters is defined in

| Pharmacopoeia | Chapter | Key Differences | |---------------|---------|------------------| | USP | <841> Specific Gravity | Allows 25 °C as standard reference; uses "specific gravity" term. | | JP | 2.56 | Similar to Ph. Eur. but includes additional hydrometer method. | | Ph. Eur. | 2.2.5 | Strict 20/20 reference; prefers pycnometer or validated digital meters. |