Loss on Drying vs. Moisture Content : Exploring the Contrast

This article provide information about difference between Loss on Drying and Moisture Content.

Loss on Drying vs. Moisture Content : Exploring the Contrast

What is mean by Loss on Drying ?

Loss on drying (LOD) is a Inprocess checks or analytical method used in various pharmaceutical industries to evaluate the amount of moisture and volatile substances present in a drug substance or Drug product.

LOD Testing Instrument Used, Description and Methodology :

LOD Testing is performing on the instruments termed  as Moisture analyzer. It work on principle of  thermo-gravimetric principle, also often called as ‘Loss on Drying‘ (LOD) principle. Instrument consists of a weighing and halogen heating unit.

It is Critical Inprocess checks at granulation stage  in Tablet Formulations, moreover it is used for end point detection in FBE (Fluid bed equipment) Process Technology.

In Moisture Analyzer fixed amount of material to be taken and dried on the predefined Temperature in the instrument for certain time period, Then equipment stooped automatically and calculate LOD value in %.

Sample taken in the LOD apparatus is approx. 2.5 g and Temperature setting is approx.105 Degree Celsius. It may change as per product characteristics and its developmental studies.

Temperature setting is decide during product development and it will be fixed during validation batches.

Now a days instruments calculates the LOD automatically. But only to understand, plz find formula for calculating the LOD value as below :

What is mean by Moisture content/Water content by KF ?

Moisture content by KF means measurement of moisture i.e. water content  in a material by using a Technique called Karl Fischer titration.

This method is specifically used to determine the amount of water present in a Drug substances or Drug products in the pharmaceutical industry.

The Karl Fischer method involves a chemical reaction between the water in the sample and a reagent containing Iodine and sulfur dioxide i presence of Base and solvent . The Calculate of moisture content is depend on amount of reagent required to react with water present in tested materials.  Moisture content by KF is a highly accurate and precise method for measuring moisture levels i,e . water content in materials.

What is Major difference between LOD and Moisture Content?

LOD Test evaluates available content of water molecule with volatile substances (if any) from the material and Moisture Content by KF evaluates available content of water molecule from the material.

If same material Testing done on LOD apparatus or KF (Karl Fischer) apparatus simultaneously,  % Results may vary i.e. less or more respectively or vice versa as per material characteristics.

Importance of Water Content and Impact on Drug Stability ?

• Water content is a crucial factor in pharmaceuticals because it can affect the physical and chemical stability of drugs, their bioavailability, and overall product quality.

• High or variable water content in products can lead to physical and chemical instability. It can cause degradation, crystal growth, and changes in drug solubility, which can affect the shelf life of the product.

Purpose of Loss on drying (LOD) / Moisture Content Testing:

• The primary purpose of LOD testing in pharmaceuticals is to measure and control the moisture content of raw materials, intermediates, and finished drug products.
• Moisture content can affect the physical properties (e.g., powder flow, tablet hardness), chemical stability, and microbial quality of pharmaceuticals. High moisture content can lead to degradation, while low moisture content can cause brittleness or reduced dissolution rates.

Frequently asked questions (FAQs)

1) Why Loss On Drying (LOD) is important?

LOD is important in various industries, such as food and pharmaceuticals to ensure product quality, stability, and compliance with standards.

2) How Loss On Drying (LOD) is measured?

A sample is weighed, heated at a specific temperature, and re-weighed until a constant weight is achieved. The weight loss represents the LOD.

3) What is the standard temperature for Loss On Drying (LOD) determination?

The standard temperature for LOD determination is typically 105°C, but it can be vary depending on the sample and product requirement