Inject
A low-volume liquid or suspension passes through a clinically practical needle.
Polymer Science for Long-Acting Delivery
Injectable Depots,
Formed In Situ
InSituGels develops injectable polymer platforms that transform from free-flowing formulations into localized depots after administration—enabling controlled, sustained drug release from a single injection.
01 In-situ depot formation
01 / SCIENCE
A liquid at injection.
A depot at the site.
In-situ-forming systems transform after administration through solvent exchange, temperature response, ionic interaction or molecular self-assembly. The resulting matrix can protect an active ingredient and control its release from days to months.
Transform
Water, temperature or local chemistry triggers gelation or polymer precipitation.
Release
Diffusion and matrix degradation shape exposure across the intended interval.
Polymer architecture, API properties and depot microstructure work as one system.
02 / PLATFORM LANDSCAPE
Different triggers.
One design challenge.
01 Solvent-exchange depots +
Biodegradable PLA, PLGA and PEG–PLA systems precipitate as solvent exits and tissue water enters. This family has the strongest commercial precedent for multi-month systemic delivery.
02 Thermoresponsive gels +
Poloxamer and degradable block-copolymer solutions gel near body temperature. They are attractive for aqueous processing and local delivery, with dilution and mechanical strength as key constraints.
03 Chemical & ionic gels +
PEG, hyaluronan, alginate and chitosan networks can form through crosslinking, pH or ions. Their flexibility suits localized therapy, while gelation reproducibility and residual chemistry require care.
03 / DEVELOPMENT
Design the entire
depot system.
Success depends on more than gelation. The molecule, polymer, solvent, device and injection site must be developed together.
Start with the target profile
Dose, potency, solubility, stability and therapeutic window define the viable platform space.
Control formation and burst
Polymer identity, solvent exchange and API state determine early exposure and depot morphology.
Build predictive release tests
Real-time and accelerated methods should resolve burst, diffusion and degradation phases.
Treat the device as product
Needle, injection force, volume and rate determine what actually forms in tissue.
04 / CONNECT
Advance the science of
long-acting delivery.
InSituGels is building a focused knowledge platform for polymer depots, formulation strategy and translational development.
hello@insitugels.com ↗