In-vitro dissolution methods for controlled release parenterals and their applicability to drug-eluting stent testing

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems

Background:

• Dissolution testing is vital for characterizing in vitro dosage form performance.
• Parenteral drug products and drug/device combination products like drug-eluting stents are increasingly prevalent.
• Existing compendial methods are insufficient for these advanced parenteral dosage forms.

Purpose of the Study:

• To review current in vitro dissolution testing methods for parenteral dosage forms.
• To assess the suitability of these methods for drug-eluting stent testing.
• To highlight the need for biorelevant conditions in parenteral dissolution testing.

Main Methods:

• Review of existing literature on 'sample and separate', 'dialysis', and 'flow-through' dissolution methods.
• Analysis of methods' applicability to drug-eluting stent testing.
• Examination of approaches incorporating biorelevant parameters for parenteral dosage forms.

Main Results:

• Current methods like 'sample and separate', 'dialysis', and 'flow-through' are described.
• The review emphasizes the limitations of existing methods for drug-eluting stents.
• Attempts to incorporate biorelevant conditions and emulate in vivo scenarios are discussed.

Conclusions:

• A significant gap exists in suitable in vitro dissolution testing methods for parenteral dosage forms, particularly for biorelevant conditions.
• Reproducing in vivo transport forces (diffusive vs. convective) is critical for implanted devices.
• Further development of predictive in vitro models is essential for parenteral drug products.