1. Overview of effervescent tablets

Effervescent tablets are a type of pharmaceutical product that has been widely used in the pharmaceutical industry for many decades. They are widely used in Europe, America and many other regions around the world. The granulation of effervescent tablets is a very important step as it directly affects the quality of the finished product, such as the stability of the drug.

Effervescent tablets have the main advantage of being easy to use, especially effective for patients who are children. However, their production is more complicated than traditional tablets, especially the selection of technology and equipment.


2. Effervescent reaction

Effervescence is the phenomenon of many gas bubbles escaping from the solution from a chemical reaction between carbonate salt and organic acid, for example: sodium bicarbonate and citric acid.


3. Drug formula and raw materials

Basic effervescent tablets include the following components

 - Active Pharmaceutical Ingredients

 - Acidic material, typically citric acid, tartaric acid, ascorbic acid, acid anhydride, acid salt

 - Source of CO2 (alkaline material), typically NaHCO3 or Na2CO3

 - Adhesive

 - Lubricant excipient

 - Additives: colorants, sweeteners, flavorings…

Among them, the acidic and alkaline materials account for most of the weight of the drug.


4. Production of effervescent tablets

Because effervescent tablets are limited in raw materials compared to traditional forms of drugs and most of the raw materials have very high hygroscopicity, the production for this form of drug preparation must be strictly controlled. For example, the air inside the entire factory must be controlled ≤ 23 oC and ≤ 20%RH

The production of effervescent tablets on a large scale is usually done according to a semi-continuous process. The production process is standardized to achieve the highest production output. The production starts from a closed process from loading raw materials, mixing and granulating, fluidized bed drying to create semi-finished products in powder form, then compressing, packaging. The granulation process is usually done by batch. The granulation process greatly affects the quality of semi-finished and finished products in later stages. Equipment, technology for effervescent tablet production requires high safety, explosion-proof, strict production and preservation process, thoroughly evaluated


5. Granulation method

Currently, wet granulation is the most preferred method to produce effervescent tablets, because it ensures uniformity of granules, suitable for compression, thereby creating uniform tablets in terms of weight or active ingredient content. There are two wet granulation technologies: Single-step and Multi-step


Source: D.M. Parikh, Ed., Handbook of Pharmaceutical Granulation (Marcel Dekker Inc., New York, New York, USA, 1997)