STP (Standard Test Procedure) in Pharmaceuticals: Definition, Key Sections, How to Write, Case Study & 11+ FAQs

Introduction and Outcome

The STP (Standard Test Procedure) is a critical document in pharmaceutical laboratories that guides analytical testing, method validation, and technology transfer. Even a small error in an STP can lead to inaccurate results or compliance issues. A well-prepared STP ensures consistency, reproducibility, and reliability of analytical methods across laboratories and sites.

In this article, you will learn about STP in pharmaceuticals, its definition, key sections, applications, advantages, and a case study, along with answers to frequently asked questions.

What is a Standard Test Procedure (STP)?

A Standard Test Procedure (STP) is a detailed analytical document that describes step-by-step procedures for performing a specific test. It ensures that analytical methods are executed consistently and accurately.

For example:

• The STP for a chromatographic method will differ from the STP for a titration method, as each analytical technique has unique requirements.

Related:

• HPLC Method Development
• Pharmaceutical Analysis in QC and ADL | Complete Guide

11 Important Sections of a Chromatographic STP

A comprehensive STP typically includes the following sections:

1. Approval Section – Names, signatures, effective date, STP number, and status of preparer and approver.
2. Safety Considerations – Material Safety Data Sheet (MSDS), lab coat, goggles, gloves, and shields.
3. List of Chemicals and Reagents – Required chemicals, grade, manufacturer, and part numbers.
4. Mobile Phase Preparation – Buffer preparation, solvent mixing, filtration, and adjustments.
5. Chromatographic Conditions – Instrument details, column, wavelength, flow rate, injection volume, temperature, run time, and diluent.
6. System Suitability & RT/RRT Table – System suitability criteria, retention time (RT), and relative retention time (RRT).
7. Solution Preparation – SST (System Suitability Test), QL, standard, and sample solutions.
8. Procedure – Injection order, integration method, and handling of peaks.
9. Calculation – Percent area, area normalization, or external standard methods.
10. Typical Chromatograms – Blank, SST, QL, standard, and sample chromatograms.
11. Abbreviations – Full forms of abbreviations used in the STP.

Note: Some companies also include molecular formulae and chemical structures of analytes.

Applications of Standard Test Procedures (STP)

STPs are used to:

• Perform routine analysis in analytical research labs
• Prepare monographs in QC departments
• Conduct analytical method validation and mini-validation
• Facilitate technology transfer between labs or sites

Case Study: STP for Related Substances of an API

Conclusion

The accuracy and reliability of pharmaceutical analyses depend on a well-prepared STP. Each STP must be carefully reviewed and approved by qualified personnel to ensure reproducibility and compliance.

Related:

• Key Differences Between SOP and STP
• Monograph And Standard Test Procedure (STP)

FAQS

What is the testing procedure (standard test procedure)?

A Testing procedure is an Analytical document that contains a detailed analysis procedure of any test of the pharmaceuticals

What are different applications of STP (standard test procedure)?

STP is used to perform analysis in R&D, to prepare monograph in QC and to perform technology transfer.

What is the standard test method?

Standard test method contains complete

Why is STP important in pharmaceutical analysis?

STPs ensure reproducibility, method validation, and technology transfer across laboratories, reducing errors and maintaining compliance with regulatory standards.

How do you write an STP?

An STP is written by including sections such as approval, safety, chemicals list, mobile phase preparation, chromatographic conditions, solution preparation, procedure, calculation, typical chromatograms, and abbreviations.

Can STP be used for technology transfer?

Yes, STPs are critical for transferring analytical methods from one site to another, ensuring consistency and compliance.

What safety precautions should be included in an STP?

Include MSDS review, personal protective equipment (PPE) like lab coats, gloves, goggles, and work in fume hoods when necessary.

Are STPs used only for chromatographic methods?

No, STPs are used for various analytical methods like titration, spectroscopy, dissolution tests, and more.

Further reading:

• What is STP in the chemical industry?

Abbreviations:

• STP: Standard test procedure
• SST: System suitability test
• DL: Detection limit:
• QL: Quantification limit
• RT: Retention Time
• RRT: Relative retention time
• MSDS: Material safety data sheet