USP <1724> - Semisolid Drug Products - Performance Tests

What it says

Semisolid dosage forms, including creams, ointments and gels, should be evaluated using performance tests appropriate to their intended use, such as in vitro release testing, to characterize how the drug is released from the formulation and support consistent product quality across batches and after formulation or manufacturing changes.

Paraphrased for plain-language clarity. Always verify against the current published regulation text.

What it means in practice

• In vitro release testing for semisolids plays a role roughly analogous to dissolution testing for solid oral dosage forms, providing a routine, discriminating way to detect whether a batch's release characteristics have shifted from what clinical and stability data support.
• Because semisolid formulations are physically complex, with structure, viscosity and drug distribution all affecting release, performance test results can be sensitive to even minor manufacturing process variations, such as mixing time or cooling rate.
• A change in raw material supplier or grade, even one that seems chemically equivalent, can alter a semisolid's microstructure enough to change its performance test results.

What inspectors look for

• Whether performance testing appropriate to the semisolid dosage form is actually built into the release and stability testing program, not substituted entirely by chemical assay alone.
• Whether manufacturing process parameters known to affect semisolid structure, such as mixing or cooling conditions, are controlled and monitored consistently batch to batch.
• Whether a raw material or process change was evaluated for its impact on performance test results before being implemented.

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