Random Sample

Sample in which the different fractions of the material have an equal probability of being represented. [26]

Random Variation

Variation in the measured property whose distribution of results shows no predictable pattern. [4]


The range of an analytical procedure is the interval between the upper and lower concentration (amounts) of analyte in the sample (including these concentrations) for which it has been demonstrated that the analytical procedure has a suitable level of precision, accuracy and linearity. [14]

Rapidly Dissolving Products

An immediate release solid oral drug product is considered rapidly dissolving when not less than 80% of the label amount of the drug substance dissolves within 15 minutes in each of the following media: (1) pH 1.2, (2) pH 4.0, and (3) pH 6.8. [9]

Raw Material

A general term used to denote starting materials, reagents and solvents intended for use in the production of intermediates or excipients. [1, 2, 3]

Raw material and starting material are not equivalent, as starting material has a different meaning in a regulatory context.

Re-evaluation Date/(Retest Date)

The date beyond which the bulk pharmaceutical excipient should not be used without further appropriate re-examination to ensure that it is still in conformance with the specification. [1, 3, 7]

Re-evaluation Interval

The duration, normally expressed in months or years from the date of manufacture, throughout which the excipient should continue to conform to the specification and after which should be tested to confirm it continues to meet specification. [4]

Re-test Period

The period of time during which the drug substance is expected to remain within its specification and, therefore, can be used in the manufacture of a given drug product, provided that the drug substance has been stored under the defined conditions. After this period, a batch of drug substance destined for use in the manufacture of a drug product should be re-tested for compliance with the specification and then used immediately. A batch of drug substance can be retested multiple times and a different portion of the batch used after each re-test, as long as it continues to comply with the specification. For most biotechnological/biological substances known to be labile, it is more appropriate to establish a shelf life than a re-test period. The same may be true for certain antibiotics. [13]


A material that is used to chemically modify a starting material or intermediate during the manufacture of an excipient.

Recall (USA: see Retrieval)

A process for withdrawing or removing a pharmaceutical material from the distribution chain because of defects in the materials or complaints of a serious nature. The recall might be initiated by the manufacturer/importer/distributor or a responsible agency. [3, 18]

Recommended Re-Evaluation Date

That date beyond which the bulk pharmaceutical excipient should not be used without further appropriate reexamination. [6]

Recommended Re-evaluation Interval

The period beyond which the bulk pharmaceutical excipient should not be used without further appropriate re-examination.


A comparison between the theoretical quantity and the actual quantity. [20]


Document stating results achieved and/or providing evidence of activities performed. The medium may be paper, magnetic, electronic or optical, photographic etc. or a combination thereof. [1, 3]


The introduction of all or part of previous batches (or of redistilled solvents and similar products) of the required quality into another batch at a defined stage of manufacture. It includes the removal of impurities from waste to obtain a pure substance or the recovery of used materials for a separate use. [20]

Reduced Frequency Testing Program

See "Skip-Lot Testing". [8]

Reference Standard, Primary

A substance that has been shown by an extensive set of analytical tests to be authentic material that should be of high purity. This standard can be: (1) obtained from an officially recognised source, or (2) prepared by independent synthesis, or (3) obtained from existing production material of high purity, or (4) prepared by further purification of existing production material. [2]

Reference Standard, Secondary

A substance of established quality and purity, as shown by comparison to a primary reference standard, used as a reference standard for routine laboratory analysis. [2]


The process of putting a new label on the material (see also labeling). [3, 18]


An expression of the degree to which a measurement performed by different people at different times and under different circumstances produces the same results (see also validity). [25]

Reliable Quantification of Drug Needs

A careful evaluation of the quantities needed of each drug, based on either adjusted past consumption or anticipated pattern of diseases and standard treatment, which can be expected to match actual needs reasonably well. [25]


The action of changing the packaging of the material. [3, 8, 18]


Repeatability expresses the precision under the same operating conditions over a short interval of time. Repeatability is also termed intra-assay precision. [14]

Replacement in Kind

Manufacturing equipment that uses the same operating principle and is of similar construction or packaging components made with the same materials of construction and sealed in a similar manner. [5]

Reporting Threshold

A limit above (>) which an impurity should be reported.

Representative Sample

A quantity of the excipient taken according to a prescribed rationale so as to accurately portray the material being sampled (e.g., a batch).


Repetition of an activity that is a normal part of the manufacturing process and that has been documented previously. [1]


Reproducibility expresses the precision between laboratories (collaborative studies, usually applied to standardization of methodology). [14]


The explicit or implicit needs or expectations of the governing standards.

Residual Solvents

Residual solvents are defined as organic chemicals that are used or produced in the manufacture of active substances or excipients, or in the preparation of medicinal products. ICH Q3C Impurities: Residual Solvents [6]


Material, process, equipment or personnel required to perform an activity or service.

Responsible Care

A voluntary program to achieve improvements in environmental, health and safety performance. Adopted by most Chemical Industry associations worldwide.

Retained Sample

Representative sample of a batch/delivery that is sufficient quantity to perform at least 2 full quality control analyses and will be kept for a defined period of time.

Retest Date

The date when a specific batch of material must be re-examined to ensure that it is still suitable for use.

Retest Interval

(Re-evaluation Interval) [4]

Retest/Re-evaluation Interval

The duration, normally expressed in months or years, from the date of manufacture, throughout which the excipient is expected to continue to conform to the specification and after which must be tested to confirm it continues to meet the specifications.


Process for the removal of an excipient from the distribution chain. [1, 3]

Retrospective Validation

Validation based upon historical records that demonstrates the process can achieve the desired output.


Repeated validation of an approved process (or a part thereof) to ensure continued compliance with established requirements. [23]

Reversible Toxicity

The occurrence of harmful effects that are caused by a substance and which disappear after exposure to the substance ends. [16]


Subjecting previously processed material that did not conform to standards or specifications to processing steps that differ from the normal process. [1, 2]


The combination of the probability of occurrence of harm and the severity of that harm (ISO/IEC Guide 51). [10]

Risk Acceptance

The decision to accept risk (ISO Guide 73). [10]

Risk Analysis

The estimation of the risk associated with the identified hazards. [10]

Risk Assessment

A systematic process of organizing information to support a risk decision to be made within a risk management process. It consists of the identification of hazards and the analysis and evaluation of risks associated with exposure to those hazards. [10]

Risk Communication

The sharing of information about risk and risk management between the decision maker and other stakeholders. [10]

Risk Control

Actions implementing risk management decisions (ISO Guide 73). [10]

Risk Evaluation

The comparison of the estimated risk to given risk criteria using a quantitative or qualitative scale to determine the significance of the risk. [10]

Risk Identification

The systematic use of information to identify potential sources of harm (hazards) referring to the risk question or problem description. [10]

Risk Management

The systematic application of quality management policies, procedures, and practices to the tasks of assessing, controlling, communicating and reviewing risk. [10]

Risk Reduction

Actions taken to lessen the probability of occurrence of harm and the severity of that harm. [10]

Risk Review

Review or monitoring of output/results of the risk management process considering (if appropriate) new knowledge and experience about the risk. [10]


The robustness of an analytical procedure is a measure of its capacity to remain unaffected by small, but deliberate variations in method parameters and provides an indication of its reliability during normal usage. [14]

Route of Exposure/Administration

The method by which the drug product containing the excipient is administered to the patient. [7]