Incompatibility of a nonsterile compound may be indicated by:

Incompatibility in a nonsterile compound can be identified through various physical, chemical, and therapeutic changes.An unexpected change in odoris a key indicator of chemical instability, contamination, or degradation of a compounded preparation. Some ingredients may break down into volatile compounds, leading to noticeable odor changes.

A. A clear solution→ Incorrect; clarity alone does not indicate incompatibility.Some solutions may be clear but still chemically unstable.

B. The use of a pH buffer system→ Incorrect; buffer systems are used to maintain pH stability and prevent incompatibility rather than indicate it.

D. Suspension particles settling to the bottom of a container→ Incorrect; suspensions naturally settle and require shaking before use.This is not necessarily a sign of incompatibility.

Other Answer Choices Explained:References:

USP <795> Pharmaceutical Compounding—Nonsterile Preparations

PTCB PTCE Exam Content Outline (Medication Safety & Quality Assurance)

Remington: The Science and Practice of Pharmacy