Arithmetic mean roughness value. The arithmetical average of all absolute distances of the roughness profile R from the center line within the measuring length lm.

Random Sample

A random sample is defined a unit taken from a larger population of such units.In a simple random sample each unit has an equal chance of being included.

Range for critical process parameter

The range for each process parameter generally developed on laboratory-, pilot-, or plant-scale batches that encompasses values that are capable of producing intermediates and APIs having acceptable quality attributes. 

Raw Data

Raw data in the GMP environment can be defined as any work sheets, records, memoranda, notes or exact copies thereof, that are the result of original observations and activities of a study, or a process, and are necessary for the reconstruction and evaluation of the report of that study or process. Raw data includes e.g. photographs, computer printouts, magnetic media, including dictated observations, and recorded data from automated instruments where applicable.

Raw Material

Any ingredient intended for use in the production of drug products or APIs. These may include starting materials, process aids, solvents, and reagents. reagent: A substance, other than a starting material or solvent, that is used in the manufacture of an API or intermediate. 


Reanalysis is the repetition of some or all conducted analytical testing. This is different than Retesting or a Resample.


The product recall is basically the removal of one or more batches of product from the market, thought or known to be in violation of one or more laws or rules in that country with full knowledge of one or more regulatory agencies.


The term reconciliation is used to for performing a comparison between the amount of product or materials theoretically produced or used and the amount actually produced or used.


Any treatment of materials by a process intended to make them suitable for further use.

Reference Standard

A reference standard is defined as any chemical substance or mixture, or analytical standard, or material other than a test substance that is used for the purposes of establishing a basis for comparison with the test substance for known chemical or biological measurement.

Regulatory Authority

The Regulatory Authority (Regulatory Body) is a legislatively empowered organization, group, or individual charged with evaluating the compliance profile of a site and/or product as measured against applicable standards.

Regulatory Compliance

The term Regulatory Compliance is used for the system within the organization administered by the Quality Assurance Unit to ensure adherence to the applicable Regulatory Requirements.

Regulatory Requirements

The term Regulatory Requirements is often used for mandates and standards enforced by a government-appointed agency designed to protect the public interest by assuring identity, potency, Quality, purity, safety and efficacy of drugs, devices and components entering into the market place.

Regulatory Specifications

For Pharmacopoeia articles, the specifications in the current edition of the pharmacopoeias are those legally recognized and are used by the agencies when determining compliance with the Regulations or the defined limits within which physical, chemical, biological and microbiological test results for a Drug Substance / API (Active Pharmaceutical Ingredient) or a Drug Product should fall when determined by the Regulatory methodology.

Release Specification

The release specifications are the specifications which must be met to release a Product. This might be a combination of physical, chemical, biological and microbiological test requirements that determine that a final product is suitable for release.


Person or institution who processes, conditions, renovates, repackages, restores, or does any other act to a finished product that significantly changes the product performance or safety specifications, or intended use.

Repeating a chemical reaction

Adding fresh reagents or solvents to unreacted or base material and repeating a chemical reaction from its beginning. This excludes those situations where a chemical reaction is continued or extended in the same vessel with the addition of more solvent, to ensure completion of a reaction or increase the yield and/or purity of the API (e.g., continuation of a hydrogenation step). 

Representative Sample

A representative sample is defined as a sample that is based on rational criteria such as random sampling, and is intended to assure that the sample is representative of the sampled material.


A sample that consists of a number of units that are drawn based on rational criteria such as random sampling and intended to assure that the sample accurately portrays the material being sampled.


The treatment of all or a part of a batch of product from a defined stage of production with the original process so that it’s quality may be rendered acceptable by one or more additional operations.

ICH Q7A defines reprocessing as is introducing an intermediate or Drug Substance…back into the process and repeating appropriate chemical or physical manipulation steps (e.g., distillation, filtration, chromatography or milling) that are part of the established manufacturing process.


Introducing an intermediate or API that does not conform to standards or specifications, back into the process and repeating one or more steps that are part of the established manufacturing process (e.g., recrystallization using the same solvent).


A resample is an additional sample taken from the batch of material Resample should only been taken if the original sample used for testing is deemed not representative of the batch or the original sample has been compromised in some manner.

Reserve Sample

A reserve sample also called retained sample is a sample being representative of the batch from which it was taken and which is stored over a pre-determined period of time to perform testing if needed against established specifications.

Retest Date

The retest date of a material is the date when material must be tested again to assure that the material still meets all specification.


The date when the Product (API) should be re-examined to ensure that it is still suitable for use.

Retest Period

The retest period is the timeframe during which the Drug Substance / Active Pharmaceutical Ingredient (API) can be considered to remain within the predefined specification and therefore, acceptable for use.


The period of time during which the API can be considered to remain within specifications, and therefore acceptable for use in the manufacture of a given drug product, provided that it has been stored under defined conditions. After this period, the API should be retested for compliance with specifications before use.


Retesting is defined as the conduct of repeating an analytical procedure on a different portion of the same sample.

Retrospective concurrent drug use evaluation

One of three forms of evaluation of prescribing patterns to specifically determine the appropriateness of drug therapy. Retrospective drug use evaluation is conducted after the therapy has been completed. There are two other forms of drug use evaluation: concurrent (during the course of drug therapy) and prospective (before or at the time of despensing). 

Retrospective Process Validation

A Retrospective Process Validation is a validation of a process which is already in use based upon accumulated historical data’s conformance to predetermined acceptance criteria.


Establishing documented evidence that a system does what it purports to do based on a review and analysis of historic information. It is normally conducted on an API already being commercially distributed and is based on accumulated production, testing, and control data.

Retrospective Qualification

A Retrospective Qualification is qualification of a system already in use based upon accumulated historical data’s conformance to predetermined acceptance criteria.

Returned Goods

Any returned finished packaged drug product not associated to a complaint or a recall.

Revalidation Process

The term Revalidation Process is used for the description of a repeated validation to provide assurance that changes in the Process or Process environment, whether introduced intentionally or unintentionally do not adversely affect process characteristics and process quality of a validated process.

Reworking - Rework

The treatment of all or part of a batch of material of unacceptable quality using an approved process other than that used to produce the original.

ICH Q7A defines reworking as subjecting an intermediate or Drug Substance (DS=API) that does not conform to standards or specifications to one or more processing steps that are different from the established manufacturing process to obtain [material of] acceptable quality (e.g., re-crystallizing with a different solvent).


US GMPs for APIs: Subjecting an intermediate or API that does not conform to standards or specifications, to one or more processing steps that are different from the established manufacturing process (e.g., recrystallizing with a different solvent).

Risk Analysis

A systematic use of available information to identify Hazards and to estimate the Risk.

Risk-benefit ratio

Relation between the risks and benefits of a given treatment or procedure. Institutional review boards located where the study is to take place determine whether the risks in a study are reasonable with respect to the potential benefits. The patient also decides if it is reasonable, in light of the risk-benefit ratio, to take part in the study.


Root mean square roughness value. (An alternative to Ra.) The RMS value of a profile calculated over a single sampling length, but can be expressed as the mean result of 5 consecutive sampling lengths. 


An abbreviation of the Latin word "recipere" which means "to take". The symbol is used at the beginning of a medical prescription.