Sunday, May 8, 2022

Active Pharmaceutical Ingredient

The active pharmaceutical ingredient is the main component of any dosage form which is pharmacologically active & provides desired therapeutic effects.

Active Pharmaceutical Ingredient Definition

The active pharmaceutical ingredient also known as API is the ingredient which is a biologically active part of the medicines or pesticides & produces the desired effect.

Component Of Dosage Form

The finalized form of a finished product is known as the dosage form. Dosage form consists mainly of two components which are given below,

  • Active Pharmaceutical Ingredient

  • Excipients

As we discussed earlier, active pharmaceutical ingredients are the main component which provides a therapeutic effect.

The ingredients in dosage form other than active pharmaceutical ingredients are known as excipients.Excipients are inert and provide no pharmacological effect.

Read About

Role and Classification of Excipients.


To understand the concept of Active pharmaceutical ingredients, take the simple daily life example of medicines used to relieve pain or fever.

If anyone is suffering from fever he or she usually takes a dosage form containing paracetamol. Paracetamol or acetaminophen is the active pharmaceutical ingredient (API) which provides us relief from fever & pain.

Strength Of Active Pharmaceutical Ingredients (APIs)

  • Active pharmaceutical ingredients may be divided into two categories one is natural & other is synthetic.

  • Different strengths of active pharmaceutical ingredients are available in the market in the form of various dosage forms.

  • The strength of the active pharmaceutical ingredient in any dosage form decides how strong the effect will be.


Metformin Hcl is a commonly used active pharmaceutical ingredient (API) which is used to control a specific diabetic condition & is available in the following strengths:

  • Metformin Hcl  500 mg

  • Metformin Hcl 850 mg

  • Metformin Hcl 1000 mg


It is confusing for most people who think that the strength mentioned on the finalized packaging indicates the tablet's weight.But the fact is that tablet strength & tablet weight are two different things.


Take a simple example of Atenolol 50 mg tablets. Here 50 mg is not the weight of the tablet rather 50 mg represents only the quantity of active pharmaceutical ingredient (API)

 in the tablet.

As we know that along with API,different excipients are also used for manufacturing of dosage form,so tablet weight may be 100 mg or 200 mg depending on the formulation.

Combination Of Active Pharmaceutical Ingredients

A dosage form may contain a single Active pharmaceutical ingredient (API) or more than one active pharmaceutical ingredient in the same dosage form to provide a therapeutic effect.


Metformin Hcl & Sitagliptin phosphate are two commonly used active pharmaceutical ingredients in a single tablet.

Manufacturing Of Active Pharmaceutical Ingredients

Manufacturing of Active pharmaceutical ingredients is a complex process where different types of compounds or raw materials are used to form APIs.The byproducts which are formed during the manufacturing of API or active pharmaceutical ingredient are known as intermediates.

Taste Of Active Pharmaceutical Ingredients

Different active pharmaceutical ingredients may have different taste which may be one of the following,

  • Bitter

  • Sour

  • Metallic

  • Saltish

  • Astringent

To mask the taste various techniques & excipients are used depending upon the type of dosage form.Tablet coating is one of the simplest examples of taste masking technique.

Examples Of Active Pharmaceutical Ingredients

Following are some examples of commonly used active pharmaceutical ingredients,

  • Diclofenac Sodium

  • Acetylsalicylic Acid

  • Ciprofloxacin

  • Omeprazole 

  • Valsartan

  • Levofloxacin

Also Read

Potency calculation of Active pharmaceutical Ingredient.

Reconciliation in pharmaceutical industries.

How to calculate Batch Size?

Role of diluents in tablet granulation.

Important SOPs

SOP for Rapid Mixing Granulator.

SOP for Spiral Mixer/Sigma Mixer

SOP for Double Cone Blender.

SOP for Wet Granulator.

SOP Of Fluid Bed Dryer

Friday, May 6, 2022

Calibration Frequency Of Measuring Instruments

One of the most confusing questions for professionals working in any pharmaceutical industry or area where measurements are involved is,What should be the calibration frequency?

or When equipment or instruments should be calibrated?  

In this article, we will discuss the following important points.

  • What is calibration?

  • Importance Of Calibration?

  • When To Perform Calibration?

  • How is Initial Calibration Frequency determined?

  • What is the traditional method used to determine calibration duration?

  • How Final Calibration frequency or due date is determined?

  • When Calibration Frequency Can Be Decreased.

  • When Calibration Frequency Can Be Increased.

What Is Calibration?

Calibration is the process in which the values of any device or instrument are compared with reference standards whose values are accurate & known.


Take a simple example of calibration of analytical balance used in a quality control laboratory.

To calibrate the balance we place standard weights on the balances & readings are recorded.

If The reading displayed on balance is the same as the value of the reference standard weight then we declare that our balance is calibrated.

Importance Of Calibration

The importance of calibration can not be ignored because of the following important facts,


The critical operations which involve measurements are greatly dependent on the accuracy of the measuring device.If the device is calibrated we can claim that our results are accurate.

Product Quality

If a product is manufactured using calibrated measuring devices it assures us that our product is of high quality.

Precise Results

By using calibrated devices we get precise results.

Reduce Cost

By using timely validated devices the down times are reduced (which may occur due to faulty readings) & cost of operation is also reduced.

When To Perform Calibration?

  • Before first time usage of a new device or instrument.

  • After the due date, recalibration is done.

  • According to manufacturer specifications.

  • To meet regulatory requirements.

  • In case of any shock or damage.

What Is Calibration Frequency?

Calibration frequency is the duration after which the device or instrument is recalibrated.

Calibration frequency is also known as Calibration Interval Or Calibration Due Date.


The general concept is that Calibration frequency is the due date which is provided by the third party and after which the device or instrument is calibrated.

This concept is wrong because the third party can not provide a due date. After all, determining the due date or calibration interval is the responsibility of the customer.

The logic behind this point is that, at the customer site the calibration status may be changed due to any shock,  damage or unsuitable conditions so Calibration Frequency as Per ISO 17025 states that,

The third-party which provides calibration services should not mention the due date or calibration interval on the certificate or the calibration label until & unless there is a mutual understanding with the customer.

Also Read

100 MCQs to revise your pharmaceutical knowledge.

How To Determine Calibration Frequency?

Now we will discuss how calibration interval or calibration frequency is determined Or in simple words how an organisation sets a calibration duration for a device or equipment.

We will divide it into 2 parts,

  • Initial Calibration Interval

  • Final Calibration Interval

Initial Calibration Interval

Initial calibration interval or frequency is the period which is set for the first time for any instrument or device.

Most  Pharmaceutical industries use ls traditional fixed initial calibration intervals like

  • Bi-Annual

  • Annual

  • After Two Years

Some Pharma uses one year as an initial calibration frequency for those devices which are used for less critical operations & twice a year for those which are used for critical processes.

Best Practice

The best practice to determine calibration interval is based on the following,

  • It is initially defined based on expert advice.

  • It is defined based on previous experience with such an instrument.

  • Based on manufacturer recommendations.

  • Based on regulatory requirements.

  • Nature of work for which it is used.

  • Frequency of use.

Final Calibration Interval

The initial calibration frequency is not final; it is set only to get data for a specific period.

When we have sufficient calibration data for a specific device we compare different values of past data and check the trend of values or results.

If all the values are within the limit from start to end we may increase the initial validation duration.

If values show variation we may decrease the duration.

When  Calibration Frequency Can Be Decreased?

As calibration is performed by third parties it increases the cost of the organisation so here we will discuss the cases where the calibration frequency can be decreased to reduce the cost & men power involved.

The calibration frequency can be decreased in following situations.

  • When the tolerance of calibration results is within range.

  • When the device or equipment is used for less sensitive or non-critical operations.

When  Calibration Frequency Can Be Increased?

Can be increased in the following cases,

  • When the drift of a device or instrument is out of defined ranges.

  • When the device shows significant drift in past results.

  • When the device is placed in a critical area.

  • When the results of a device may significantly affect the product quality.

  • When the equipment is used in an area where temperature, humidity or vibrations may affect the performance.

Also Read

Cleaning Validation In Pharmaceutical Industry

Validation | Process Validation

Difference between Validation & Calibration.

Why is a Separate Manufacturing Facility Required For Penicillin And Non Penicillin Products

Why Do We Use Three Batches For Validation

GMP vs cGMP and 21 CFR.


Saturday, April 30, 2022

SOP For Automatic Tablet Coating System

Standard Operating Procedure for perforated coating pan system or automatic tablet coater.

1.0 Purpose

The purpose of this SOP is to establish a standard procedure for operating the coating pan system

2.0 Scope

This SOP will be applicable for the tablet coater in the coating area of the production section.

3.0 Responsibility

3.1 Machine Operator is responsible for operating the tablet coater.

3.2 Production Pharmacist is responsible for the implementation of this SOP.

3.3 HOP is responsible to ensure the implementation of this SOP.

3.4 Quality Assurance Officer monitors the compliance of this SOP.

4.0 Procedure

4.1 Production Pharmacist will ensure that the tablet coater, its components and the area are properly cleaned.

4.2 Production Pharmacist will ensure that the tablet coater, its components and Area are labelled with Cleaned label status.

4.3 Before line clearance, ensure that the spray guns & air pipes are properly installed.

4.4 Take line clearance from the production officer & quality assurance inspector.

4.5 After line clearance, prepare a coating solution according to the procedure mentioned in BMR.

4.6 While the coating solution is under mixing, add tablets to the coater by opening the charging door of the coater.

4.7 Enter product name & batch number to the HMI & Load the recipe or manually add the following  parameters,

  • Inlet Air Temperature

  • Air Flow Volume

  • Atomization Air Pressure

  • Tablet Bed Temperature

  • Peristaltic Pump Speed

  • Exhaust Air Value

  • Pan Speed or Pan rpm

4.8 Open the exhaust and deduct the tablet by operating the pan in jogging mode.

4.9 Now Open the heating & inlet airflow system and preheat or warm the tablets according to the BMR.

4.10 Check the average weight of 100 core tablets and the hardness of 10 tablets before starting the coating process.

4.11 Adjust the distance between spray guns & moving tablet bed.

4.12 Meanwhile the coating suspension is ready and starts coating operation by adjusting the atomization air pressure, spray pattern,pan speed and peristaltic pump speed.

4.13 The coating parameters are adjusted according to BMR until all the coating suspension is used.

4.14 Check the average Weight of  100 tablets to ensure that our target weight is achieved.

4.15 Turn off the peristaltic pump and atomization air pressure, dry the tablets according to BMR.

4.16 Turn off the heating system & ensure temperature normalization of tablets.

4.17 When tablet temperature is normal, discharge the tablets in containers.

4.18 Again weigh the average weight of 100 tablets & also check the bulk weight of the whole coated batch.

4.19 Calculate yield and store the coated batch in a storage area.

4.20 Record the activity in the logbooks.

5.0 Abbreviations

5.1 SOP: Standard Operating Procedure

5.2 rpm:   Rounds per minute

5.3 BMR: Batch Manufacturing Record

5.4 QA:    Quality Assurance

5.5 HOP: Head Of Production

Also Read:

SOP For Compression Machine.

SOP for Rapid Mixing Granulator.

SOP for Spiral Mixer/Sigma Mixer

SOP for Double Cone Blender.

SOP for Wet Granulator.