Preformulation experiences and in vitro model studies with spironolactone-containing suppositories

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems

Background:

• Rectal suppositories are a viable dosage form for drug delivery.
• Spironolactone, a diuretic, requires optimal formulation for effective rectal administration.

Purpose of the Study:

• To determine the optimal suppository base for spironolactone rectal formulations.
• To investigate the impact of solubility-enhancing additives on drug release from suppositories.

Main Methods:

• Experimental selection of suppository bases (lipophilic vs. hydrophilic).
• In vitro drug release studies using varying pH acceptor phases, diffusion times, and sampling intervals.
• Stability assessment of the selected suppository formulation during storage.

Main Results:

• Hydrophilic Macrogolum 1540 was identified as the optimal suppository base.
• Spironolactone exhibited the most favorable release and diffusion characteristics from Macrogolum 1540 suppositories.
• Suppositories maintained stability during storage with no significant decrease in drug release (p < 0.05).

Conclusions:

• Macrogolum 1540 is a suitable base for spironolactone rectal suppositories.
• The optimized formulation ensures stable and effective drug release for diuretic therapy.