Analytical Chemistry & Physical Testing

This assay demonstrates that the declared antimicrobial preservation agent present within a multiple-dose injectable does not exceed the labeled amount by more than 20%.

Evaluating a drug product’s physical appearance can be subjective; however, it is a vital procedure for product quality and understanding. As an example, color can serve as a gross purity marker and a way to detect contaminants and degradents introduced during synthesis or storage.

The types of chromatography useful in qualitative and quantitative analysis employed in USP procedures include column, gas, paper, thin-layer (including high-performance thin-layer chromatography), and pressurized liquid chromatography (commonly called high-pressure or high-performance liquid chromatography).

This standard addresses the microbiological integrity of sterile product packaging, including the container, closure system, and sterile barrier packaging of medical devices, including in vitro diagnostic products.

This standard ensures the consistency of drug substance within a batch aligns with the narrow range around the label claim.

Elemental impurities are defined as residual catalysts or environmental contaminants that may be present in drug substances, excipients, or drug products. Whether these impurities occur naturally, are added intentionally, or are introduced inadvertently, testing is required for assurance of the specified levels.

The IR absorption spectrum of a substance provides some of the most conclusive evidence of the identity of the substance. This standard, and corresponding methods, are integral for monograph testing and product quality.

Melting point (MP) determination is a raw material and drug product characterization assay. Most substances exhibit a melting transition, spanning the temperatures at which the first noticeable change of phase is detected to when no solid phase is detected. MP methods must be carefully selected to generate certifiable results for quality control and quality assurance.

Particulate matter in injections (or parenteral infusions) assays determines the presence of mobile undissolved particles, other than gas bubbles, unintentionally present in the solutions.

pH measurements are characterization assays to determine or confirm pH levels for drug compatibility, quality control, and/or shelf-life stability concerns. For compendial assays, pH is defined as the value measured by a properly calibrated, potentiometric sensor and measuring system.

Methods to determine that residual solvents used or produced in the manufacture of drug substances or excipients or in the preparation of drug products do not exceed specified ranges. Residual solvents are organic volatile chemicals with no therapeutic benefit, and must be removed to the extent possible for quality-based requirements.

Many pharmaceutical substances, like some crystals and many pharmaceutical liquids or solutions of solids, are optically active. For appropriate substances, optical rotation assays are highly informative characterization assays and the best means for distinguishing optically active isomers from each other, making this test an essential part of identity and purity.

Guided by USP 921, Karl-Fischer titration is used to determine water content in a variety of substances. Many life science products either are hydrates or contain water, and the determination of the water content is important in demonstrating compliance.