Decomposition of aminophylline in suppository formulations

Area of Science:

• Pharmaceutical Chemistry
• Drug Stability
• Formulation Science

Background:

• Aminophylline is a common bronchodilator.
• Suppositories are a common dosage form.
• Drug degradation can impact efficacy and safety.

Purpose of the Study:

• To investigate the degradation of aminophylline suppositories.
• To identify the decomposition products.
• To understand the impact of storage on aminophylline suppositories.

Main Methods:

• USP XIX assay for ethylenediamine content.
• Specific method for primary amine analysis.
• Melting point determination.
• Accelerated decomposition experiment.

Main Results:

• Stored aminophylline suppositories showed ethylenediamine deficiency.
• Decomposition products included insoluble diamides formed from ethylenediamine and fatty acids.
• High melting point of decomposition products indicated poor solubility.

Conclusions:

• Ethylenediamine in aminophylline can react with suppository base fatty acids.
• This reaction forms insoluble amide decomposition products.
• Degradation impacts the quality and stability of aminophylline suppositories.