Partition-controlled progesterone release from waterborne, in situ-gelling materials

Area of Science:

• Biomaterials science
• Polymer chemistry
• Reproductive medicine

Background:

• Developing effective and long-lasting contraception methods is a public health priority.
• Injectable drug delivery systems offer advantages in patient compliance and targeted delivery.
• Intrafallopian tube embolization requires a system for sustained release of contraceptives.

Purpose of the Study:

• To evaluate the long-term, constant zero-order release of progesterone from a novel waterborne, in situ-gelling, injectable material.
• To assess the potential of this material for use in an intrafallopian tube embolization system for contraception.

Main Methods:

• Poly(ethylene glycol) diacrylate (PEGDA) or poly(propylene glycol) diacrylate (PPODA) were combined with pentaerythritol-tetrakis (3-mercaptopropionate) to form a 75 wt.% emulsion.
• The emulsion was crosslinked via Michael-type addition reaction to form a hydrophobic solid in situ.
• Progesterone (5.5 or 25 wt.%) was incorporated into the material, which was then formed into cylindrical samples.

Main Results:

• The in situ-gelling materials formed hydrophobic solids within minutes.
• Samples with 25 wt.% progesterone exhibited constant release of approximately 40 microg/day for over 50 days.
• This zero-order, partition-controlled release profile was observed in both PEGDA and PPODA systems.

Conclusions:

• The developed injectable, in situ-forming system provides sustained, zero-order release of progesterone.
• This material holds promise for enhancing the efficiency of intrafallopian tube embolization systems for contraception.
• The system overcomes limitations of traditional preformed hydrophobic matrices by enabling in situ gelation and drug release.