Intermediate precision expresses within-laboratory variation, as on different days, or with different analysts or equipment within the same laboratory. In this context, reproducibility refers to the use of the analytical procedure in different laboratories, as in a collaborative study. Precision may be a measure of either the degree of reproducibility or repeatability of the analytical method under normal operating conditions. The precision of an analytical method is usually expressed as the standard deviation or relative standard deviation (coefficient of variation) of a series of measurements.

The precision of an analytical method is the degree of agreement among individual test results when the method is applied repeatedly to multiple samplings of a homogeneous sample. Recognizing the legal status of USP and NF standards, it is essential, therefore, that proposals for adoption of new or revised compendial analytical methods be supported by sufficient laboratory data to document their validity. Also, according to these regulations, users of analytical methods described in the USP and the NF are not required to validate accuracy and reliability of these methods, but merely verify their suitability under actual conditions of use. The Current Good Manufacturing Practice regulations require that test methods, which are used for assessing compliance of pharmaceutical products with established specifications, must meet proper standards of accuracy and reliability. According to Section 501 of the Federal Food, Drug, and Cosmetic Act, assays and specifications in monographs of the United States Pharmacopeia and the National Formulary constitute legal standards.

Test procedures for assessment of the quality levels of pharmaceutical products are subject to various requirements.

Usp dissolution validation