An improved high-performance liquid chromatography assay for spironolactone analysis

Area of Science:

• Pharmaceutical Sciences
• Analytical Chemistry

Background:

• Extemporaneous formulation of medications is crucial for patient-specific dosing.
• Spironolactone is a widely used diuretic and antihypertensive agent.
• Ensuring the stability and accurate quantification of extemporaneously prepared suspensions is essential.

Purpose of the Study:

• To prepare a liquid suspension dosage form of spironolactone (5 mg/ml) from commercially available tablets.
• To establish and validate a stability-indicating High-Performance Liquid Chromatography (HPLC) assay for the spironolactone suspension.
• To assess the stability of the prepared suspension under various stress conditions.

Main Methods:

• Preparation of a 5 mg/ml spironolactone liquid suspension from 25 mg tablets.
• Development of a stability-indicating HPLC assay method.
• Forced degradation studies (heat, extreme pH) to assess method specificity.
• Analysis of drug concentration and identification of potential interferences.

Main Results:

• A stable extemporaneously formulated spironolactone liquid suspension (5 mg/ml) was successfully prepared.
• The developed HPLC method is stability-indicating, showing no interference from degradation products or the internal standard (hydrocortisone 21-acetate).
• The analytical method is simple, utilizing a buffer-free mobile phase consistent with column storage recommendations, saving analytical time.

Conclusions:

• The established HPLC method is suitable for accurately quantifying spironolactone in extemporaneously prepared liquid suspensions.
• The analytical method's simplicity and efficiency make it practical for routine pharmaceutical analysis.
• The study confirms the stability-indicating nature of the developed analytical procedure for spironolactone formulations.