The key difference between azelaic acid and salicylic acid is that azelaic acid is an aliphatic compound, whereas salicylic acid is an aromatic compound.
Azelaic acid is an organic compound with the formula HOOC(CH2)7COOH while Salicylic acid is an organic compound having the chemical formula C7H6O3. Both azelaic acid and salicylic acid are carboxylic acid group-containing organic compounds. They have different chemicals structures and different chemical and physical properties.
CONTENTS
1. Overview and Key Difference
2. What is Azelaic Acid
3. What is Salicylic Acid
4. Side by Side Comparison – Azelaic Acid vs Salicylic Acid in Tabular Form
5. Summary
What is Azelaic Acid?
Azelaic acid is an organic compound with the formula HOOC(CH2)7COOH. Also, this compound falls under the category of dicarboxylic acids. It appears as a white coloured powder, and we can find this acid in wheat, barley, and rye plants. Furthermore, this compound is the precursor for many compounds including polymers and plasticizers. Also, it is an ingredient in many hair and skin conditioners.
Figure 01: Chemical Structure of Azelaic Acid
The molar mass of azelaic acid is 188.22 g/mol. It is an aliphatic molecule having carboxylic acid groups at the two ends of a chain of carbon atoms. In the industrial-scale applications, this compound is produced by ozonolysis of oleic acid. However, it is naturally produced by some forms of yeast that live on the skin. Moreover, bacterial degradation of nonanoic acid also gives azelaic acid.
What is Salicylic Acid?
Salicylic acid is an organic compound having the chemical formula C7H6O3. It is very useful as a medication that helps to remove the outer layer of the skin. Salicylic acid is a colourless to white crystalline solid that is odourless as well. The molar mass of this compound is 138.12 g/mol. Also, the melting point of salicylic acid crystals is 158.6 °C and, it decomposes at 200 °C. Furthermore, these salicylic acid crystals can undergo sublimation at 76 °C (sublimation refers to the conversion of a solid directly into its vapour phase without going through a liquid phase). The IUPAC name of this organic compound is 2-Hydroxybenzoic acid.
Figure 02: Chemical Structure of Salicylic Acid
Salicylic acid is an important medication. It is useful in treating warts, dandruff, acne and other skin disorders due to its ability to remove the outer layer of the skin. Therefore, this compound is a major ingredient in manufacturing skincare products; for example, it is an ingredient in some shampoos to treat dandruff. Moreover, it is important in manufacturing Pepto-Bismol, a medication used to treat gastrointestinal disorders. Salicylic acid is also useful as a food preservative.
What is the Difference Between Azelaic Acid and Salicylic Acid?
Azelaic acid is an organic compound with the formula HOOC(CH2)7COOH while Salicylic acid is an organic compound having the chemical formula C7H6O3. The key difference between azelaic acid and salicylic acid is that azelaic acid is an aliphatic compound, whereas salicylic acid is an aromatic compound. Moreover, azelaic acid contains two carboxylic acid groups per molecule, while salicylic acid contains one carboxylic acid group per molecule.
The following table summarizes the difference between azelaic acid and salicylic acid.
Summary – Azelaic Acid vs Salicylic Acid
Both azelaic acid and salicylic acid are carboxylic acids. The key difference between azelaic acid and salicylic acid is that azelaic acid is an aliphatic compound, whereas salicylic acid is an aromatic compound.
Reference:
1. “Azelaic Acid.” Wikipedia, Wikimedia Foundation, 19 Apr. 2020, Available here.
Image Courtesy:
1. “Azelaic acid” By User:Edgar181 – Own work; uploaded to en-wiki by User:Edgar181 as en:Image:Azelaic_acid.png; transferred to Commons by User:InfoCan (Public Domain) via Commons Wikimedia
2. “Salicylic acid chemical structure” (CC BY-SA 3.0) via Commons Wikimedia