Reviewable Unit

A collection of one or more Submission Units grouped together (usually by subject) that collectively become part of a Submission for purpose of review.


Process of subjecting the non-conforming material to a different manufacturing process to get a product meeting all the predefined specifications.

Reference Material

Biological material of defined biological activity which can be used as calibrant and/or positive control and/or monitor.

Reye Syndrome

Encephalopathy (general brain disorder) in children following an acute illness such as influenza or chickenpox. Symptoms include vomiting, agitation, and lethargy. This condition is often associated with the use of certain medicines (e.g., aspirin) and may result in coma or death.

Reference Sample

A sample of a batch of starting material, packaging material, intermediate or finished product which is stored for the purpose of being analysed should the need arise during the shelf-life of the batch concerned.


An RNA molecule capable of acting as an enzyme.

Reference Standard

Biological material of defined biological activity which can be used as calibrant and/or positive control and/or monitor.

Risk Analysis

The process of identifying and analyzing potential issues that could negatively impact key business initiatives or projects.


A measure of the relation between the mean value of one variable (e.g. output) and corresponding values of other variables (e.g. time and cost).

Risk Assessment

The process of identifying hazards that could negatively affect an organization’s ability to conduct business.

Regulatory affairs (RA)

A profession that deals with an organization’s adherence to regulatory compliance. It is a position mostly found within regulated industries, such as pharmaceuticals, medical devices, cosmetics, agrochemicals, energy, banking, telecom, etc.

Relative risk

The ratio of the probability of an outcome in an exposed group to the probability of an outcome in an unexposed group.

Risk Management

The process of identifying, assessing and controlling threats to an organization’s capital, earnings and operations.


Proximity between measurement values obtained from repeated analyses of multiple samples from a uniform sample under identical operating conditions, including the same laboratory, tester, apparatus, equipment, serial number, reagents, and other identical operating conditions, with short time intervals between analyses.

Risk of Bias (RoB)

The risk that a study’s results will overestimate or underestimate a true intervention effect.


The repetition of a scientific experiment or trial to obtain a consistent result.

Risk Ratio (RR)

The ratio of the probability of an outcome in an exposed group to the probability of an outcome in an unexposed group.


A prescribed course of medical treatment.


A measure of whether changes in some conditions of a test method, even if small in scale, intentionally or unintentionally, do not affect the measurement results.

Reporting Bias

type of selection bias that occurs when the results of a study are skewed due to the way they are reported.


A small animal (such as a mouse, rat, squirrel, or beaver) that has sharp front teeth.


Process of treating all or part of a batch of products deemed unfit for quality during a specific production stage through one or more additional operations to bring the quality to an acceptable level.


The extent to which consistent results are obtained when an experiment is repeated.


A category of viruses that cause diarrhea in children.


The ability to withstand or recover quickly from difficult conditions.

Reproductive toxicology

Study of occurrence of adverse effects on the male and female reproductive system due to exposure to chemicals or physical agents.

Rubella (German measles)

A highly contagious disease caused by a virus which spreads easily when an infected person coughs or sneezes.

Retrospective Validation

Validation conducted based on accumulated manufacturing, testing, and management data for a product already on the market.

Respiratory Syncytial Virus (RSV)

A common respiratory virus that usually causes mild, cold-like symptoms. It can cause serious lung infections, especially in infants, older adults, and people with serious medical problems.


A contagious viral disease caused by measles virus, marked by the eruption of red circular spots on the skin. Also known as measles.

Retention sample

A sample of a fully packaged unit from a batch of finished product.

Radiation Sterilization

A non-thermal sterilization method that destroys microorganisms in a product with gamma radiation, beta particles (electron beam), or ultraviolet light.


The act of transferring all or part of a previous batch with the required quality from a defined manufacturing unit into another batch.

Raman probe

The device used in Raman spectroscopy to connect the spectrometer to the sample.

Redox potential

A measure of the propensity of a chemical or biological species to either acquire or lose electrons through ionization.

Raman spectroscopy

A non-destructive chemical analysis technique which provides detailed information about chemical structure, phase and polymorphy, crystallinity and molecular interactions. It is based upon the interaction of light with the chemical bonds within a material.

Random-Effect Method

A statistical model where the model parameters are random variables. In case of clinical trials, the reason for heterogeneity among the included studies in a meta-analysis is explained by not only variation within each primary study but also between the primary studies.

Randomization / Random Allocation

An experimental technique for assigning human participants or animal subjects to different groups in an experiment using randomization.

Randomized Clinical Trial (RCT)

Studies in which participants are randomly assigned to an experimental group or a control group. It is the gold standard for ascertaining the efficacy and safety of a treatment.

Randomized Controlled Trials

Form of scientific experiment used to control factors not under direct experimental control. By randomly allocating participants among compared treatments, an RCT enables statistical control over predicted or unpredicted influences that influence study outcomes.

Rate Constant

A coefficient of proportionality relating the rate of a chemical reaction at a given temperature to the concentration of reactant (in a unimolecular reaction) or to the product of the concentrations of reactants.

Raw Material

The chemical components that serve as the foundation for the production of intermediates or APIs.

Raw data

The data originally generated by a system, device or operation, and has not been processed or changed in any way.


Capable of causing a reaction and especially an immunological reaction.


An apparatus used to conduct chemical reactions.


An integral part of any chemical reaction.

Real Time Release Testing

The ability to evaluate and ensure the quality of in-process and/or final drug product based on process data, which typically includes a valid combination of measured material attributes and process controls.


Of or resulting from new combinations of genetic material or cells; the genetic material produced when segments of DNA from different sources are joined to produce recombinant DNA.

Recombinant DNA (rDNA)

An artificially made DNA strand that is formed by the combination of two or more gene sequences.

Recombinant protein

A protein that has been produced by the means of recombinant DNA – DNA that has been modified in order to encode the blueprint of a protein of interest.