In Situ Forming Depot as Sustained-Release Drug Delivery Systems

Area of Science:

• Pharmaceutical Sciences
• Biomaterials Engineering

Background:

• Long-acting injectable drug delivery systems are crucial for sustained therapeutic effects.
• Traditional microsphere-based systems face challenges in manufacturing scalability and process adaptability.
• In situ forming systems present a promising alternative due to inherent advantages.

Purpose of the Study:

• To provide an overview of in situ forming systems as advanced drug delivery platforms.
• To highlight the benefits and mechanisms of in situ gelling formulations.
• To discuss the evaluation methods and applications of these depot formulations.

Main Methods:

• Review of literature on in situ forming systems and their components.
• Analysis of gelling mechanisms, including physical, physiological stimuli, and cross-linking reactions.
• Examination of formulation parameters influencing drug release, such as polymers, lipids, and fatty acids.

Main Results:

• In situ forming systems exhibit low viscosity, facilitating manufacturing and administration through hypodermic needles.
• Gelling is triggered by various stimuli, enabling controlled drug release at the injection site.
• Key evaluation parameters include sol-gel transition, rheology, gel strength, and injectability.

Conclusions:

• In situ forming systems offer significant advantages over conventional long-acting injectables, including ease of administration and manufacturing.
• The tunable nature of these systems allows for tailored drug release profiles.
• Existing marketed products demonstrate the clinical viability and therapeutic potential of in situ forming depot formulations.