Stability-indicating high-performance liquid chromatographic assay for oxazepam tablets and capsules

Area of Science:

• Analytical Chemistry
• Pharmaceutical Analysis

Background:

• Oxazepam is a benzodiazepine used to treat anxiety and insomnia.
• Ensuring the stability of pharmaceutical formulations is crucial for patient safety and drug efficacy.
• Existing analytical methods may not adequately separate oxazepam from all potential degradation products.

Purpose of the Study:

• To develop and validate a stability-indicating high-performance liquid chromatographic (HPLC) assay for oxazepam.
• To identify and quantify oxazepam degradation products under various stress conditions.

Main Methods:

• Extraction of oxazepam from capsules and tablets using 2% aqueous methanol.
• Chromatographic separation on a C18 reverse-phase column.
• Elution with a methanol-water-acetic acid mixture (60:40:1).
• Detection of oxazepam at a wavelength of 254 nm.

Main Results:

• The developed HPLC assay demonstrated excellent separation of oxazepam from known and observed degradation products.
• The method achieved a detection limit of 0.1% for degradation products.
• Oxazepam degradation was observed under acidic and basic conditions, yielding specific byproducts like 6-chloro-4-phenyl-2-quinazolinecarboxaldehyde and 2-amino-5-chlorobenzophenone.

Conclusions:

• A robust and stability-indicating HPLC method for oxazepam analysis has been successfully developed.
• This assay is suitable for quality control and stability testing of oxazepam formulations.
• The study identified key degradation pathways of oxazepam under stress conditions.