Content Test in Pharmaceuticals: How and Where to Perform

Table of contents

• Introduction and Outcome
• Content test
• Techniques for required Content test
• Difference between Content test and Assay
• Applications
• Conclusion

Introduction and Outcome; Content test in Pharmaceuticals

The content test is a widely used method to detect impurities, counter ions, or related substances in Pharmaceuticals or Dosage forms. This article will clarify all doubts related to it, and you will learn:

• What is the content test?
• What are the different procedures for perform the content test?
• Why content test is required?
• What is the differance between content test and assay?
• What is the differance between content test and related substances test?
• What are the applications of the Content test?

Content test

In a content test, impurities, related compounds, or counter ions may be quantitatively or qualitatively estimated at low or specification levels. Examples; In Venlafaxine HCl, Counter ion HCl is estimated by titration method and here this test is quantitative. The heavy metal test is performed by color comparison and it will be qualitative in nature

Analytical techniques required content test

Following instruments are used to perform content test

• High-pressure liquid chromatography: Most of the Pharmaceuticals have UV absorption and hence HPLC (with UV detector) is widely used for this test. Apart from UV detector other detectors can also be used. Example: 4-Aminophenol is tested at limit 0.005% in Acetaminophen in paracetamol by HPLC method.
• Gas chromatography (GC): Content of volatile impurities or organic volatile solvents like Methanol, Ethanol, and Isopropyl alcohol in Pharmaceuticals are tested by GC and GC-HS
• FTIR: Simethicone in Antacid is performed by FTIR method and here this test is quantitative in nature.
• UV spectrophotometer: UV spectrophotometer is also used for content test. For example content each paracetamol and Ibuprofen in the Dosages Forms is performed by UV spectrophotometer. Here this test is quantitative in nature.
• Mass spectroscopic technique: GC-MS and LC -MS are generally used to estimate Genotoxic impurities at very low level or at TTC level
• AAS and ICP MS: It is used to estimate residual elemental impurities in the Drug substances or Dosages Forms.

Content test calculation methods

During content testing using chromatographic or spectroscopic methods, the external standard approach is commonly utilized. Area normalization may be employed for qualitative content testing.

Difference between Content test and Assay

Applications

The following are the uses of content tests in the Pharmaceutical industries:

• For limit test like chloride test, Bromide test, nitrate test and heavy metals test
• For test of organic volatile impurities like Methanol, Ethanol and Isopropyl alcohol in drug substances or dosages forms.
• For assay of APIs in the dosages forms

Conclusion

The content test is a commonly used method in the pharmaceutical industry. I hope this post has cleared up any doubts you may have had about the content test, and that you can now easily implement it in your routine analysis. If you have any suggestions or questions, please leave them in the comment section and I will prioritize answering them.

FAQs

What is content in pharma?

When test like impurities, related compounds, counter-ions and moisture are assessed quantitatively or qualitatively at low or specification levels then the test is called content testing. Examples; In Venlafaxine HCl, Counter ion HCl is estimated by titration method and here this test is quantitative. The heavy metal test is performed by color comparison and it will be qualitative in nature

What is the purpose of a moisture content test?

The quality like assay, impurity profile and stability of pharmaceuticals or food products depend upon the moisture. That is why the content test is performed.

What are the tests done in pharmaceutical industry?

The tests like description, solubility, LOD (loss and drying), moisture, assay, impurities profile, specific optical rotation, chiral purity and OVI (organic volatile impurities) are performed in the pharmaceuticals

What is content uniformity in pharma?

In content uniformity testing, individual dosage forms such as tablets and capsules are assayed

How to calculate moisture content?

Moisture content is performed by Karl-Fischer (KF) apparatus.

References:

• https://pharmaknowledgeforum.com/genotoxic-impurities-ttc-concept-and-insilco-system/

Abbreviations:

• UV: Ultra-violet spectrophotometer
• HPLC: High performance liquid chromatography
• GC: Gas chromatography
• GC-HS: Gas chromatography headspace
• AAS: Atomic absorption spectrophotometer
• ICP MS: Inductively coupled plasma mass spectrophotometry