How to write a sop

SOP is the standard operating procedure.SOP or standard operating procedure is a written procedure that is a step-by-step description of how a task will be performed.SOPs are written for personnel who are going to perform that specific task.

SOPs play an important role in the success of any pharmaceutical industry because any inspection or audit is usually started with checking of  SOPs.

Purpose of SOP

  • Purpose of SOP is to indicate that an organization has a defined set of procedures.
  • SOPs show that the organization has a specific policy.
  • SOPs are the backbone of an organization.
  • SOPs indicate or reflect consistency in operations.
  • A task can be completed more easily and accurately by following the SOPs or written procedures.
  • The purpose of SOP is to maintain good quality and uniformity.
  • SOPs serve as a training document.
  • SOP’s promote communication and prevent  failure.
  •  If there is no SOP there may not be consistency in operations.

SOP In Pharmaceuticals.

As the pharmaceutical industry is related to the manufacturing of medicines, there should be clearly defined written procedures for every task and operation so that good quality products can be produced. The pharmaceutical industries are regulated by different authorities and SOPs are demanded by different agencies like ISO.

ISO is international organization for standardization and ISO 9001 demands that companies must have SOPs for all those processes and operations which affect the quality of the product. The pharmaceutical industry has different sections and each section has different types of  SOPs.

Types of SOP

1.0 Production Department SOPs.

It may include 

  • Safety sops.
  • General sops.
  • SOPs for Documentation.
  • SOPs for production Operations.
  • SOPs for Operating Equipments

2.0 Quality Control  Department SOPs.

It may include,

  • SOPs for Analytical method.
  • SOPs for  Preparing Reagents.
  • SOPs for Operating Instruments.

3.0 Quality Assurance Department SOPs.

4.0 Engineering Department SOPs.

5.0 Product Development Department SOPs.

6.0 Finance Department SOPs.

7.0 Marketing Department SOP’s.

8.0 Human Resource Department SOPs.

How to write SOP

There are no official standards for writing the SOP but some important steps should be kept in mind while writing SOP.

  • SOP Should be written in Word document or Google Document.
  • Use the same Formatting style for all SOP writing, in an organization.
  • Use font size, font style and margins etc according to organizational set-standards.
  • The SOP should be written in easy wording.
  • The SOP should be written in the present sentence or active voice.
  • The SOP should not be written in the past sentence.
  • The SOP should be written by the person who knows of that activity of a task.
  • The SOP should not be too long, long SOPs are difficult to follow.
  • The SOP should be written in Steps.
  • The  SOP should not contain words like “Maybe “If possible”.
  • SOP  should be concise.
  • The SOP should contain Clear wording.
  • Use visualisation in SOPs through flow-charts or diagrams for the understanding of persons involved in performing the task.
  • SOP  should be written for personnel performing the task not just for regulatory requirements.
  • The SOP should be written in such a way that a person who has limited knowledge, can perform a task by following SOPs.

Parts of SOP

SOP consist of following parts,


  • It includes the company name.
  • It is present on all Pages of Standard Operating Procedure or SOP.
  • It is written in Bold capital letters usually font size of 16.

Type of Document

It contains document type like, STANDARD OPERATING PROCEDURE

  • Write it in capital bold letters.
  • Usually, 14 font size is used.


  • It contains the name of activity for which SOP is written e.g  COMPRESSION MACHINE
  • Write it in bold and capital letters.
  •  Usually,  font size is 12.

SOP Number

  • SOP is given a unique number depending on an in-house coding system like SOP-DC-ABC-Z.
  • DC is departmental code like PRD for production, STR for store etc.
  • ABC is a sequence number starting from 001.
  • Z is the revision number.

Effective Date

  • It is the date from which SOP is going to be implemented. Mean it is the date from which SOP will be effective for that specific activity, after approval from all concerned persons.
  • Before the effectiveness of SOP training of concerned personnel is conducted.
  • It is written as
  •  (day, month and year)

Review Date

It is the date at which SOP should be reviewed.


It includes the previous Revision number.

If SOP is new it will be Nil

Page No

It includes a total number of pages.

Signature Box

  • It includes,
  • Prepared By
  • Reviewed By
  • Approved By

Prepared By

  • It includes the name and designation of a person who writes the SOP.
  • The person is from SOP initiating department e.g production, QA, QC etc.
  • It is written as the name and designation of a person followed by signature and date.

Reviewed By

  • It includes the name and designation of a person who reviews the SOP.
  • Usually, the head of the department of the initiating department reviews the SOP.
  • It is written as the name and designation of a person followed by signature and date.

Approved By

  • It includes the name and designation of a person who approves the SOP.
  •  Usually, the head of the department of QA or Management representative/MR approves the SOP.
  • It is written as the name and designation followed by signature and date.


  • Purpose section clearly describes the need of that SOP, why it is generated.
  • For example in the case of SOP for Fluid Bed dryer, it is written as, 
  • This SOP is generated to define a standard operating procedure for the operation of the fluid bed dryer.


  • It includes the areas which are covered by a specific SOP.
  • In the case of SOP for Fluid Bed dryer, Scope is written as,
  • This SOP is for the fluid bed dryer.


This Section highlights the responsibilities of personnel for that SOP.


  • This section includes a step by step description of how a task is to be performed.
  • It should be written after a complete study of that specific task or operation for which SOP is to be established.
  • The procedure should be in such a way that it can easily be understood by the end-user.
  • It is written on A4 size white paper.
  • Usually, the font size used is 12.
  • Do not write long paragraphs.
  • Write in steps.
  • Headings and subheading should be written in bold capital letters.


Safety measures should be listed in this section.

Revision History

  • It includes the data which represent the revision history of SOP.
  • Reason for revision is mentioned in this section along with the date.


  • Annexures are specific formats which are used along with SOP for recording specific data.
  • Annexures are attached with SOP
  • e.g
  • Annexure 1 
  • Any checklist.
  • Annexure 2
  • Data recording form.

Footer of SOP

  • Footer is on every page of SOP.
  • It is usually written in 10 font size.
  • It includes,
    • SOP Number.
    • Revision Number.
    • Page Number.
    • The page number is written as x of y.
    • x is an individual page number.
    • y is the total number of pages.
    • Example, if the total number of pages are 4 then for 1st-page x of y means 1 of 4.

Important topics:

  1. SOP for Rapid Mixing Granulator.
  2. SOP for Double Cone Blender.
  3. SOP for Wet Granulator.
  4. SOP Of Fluid Bed Dryer
  5. lux level in pharmaceutical industries.
  6. HEPA filters in pharmaceuticals.