Drug release and depot testing for long-acting injectables
GelTech Labs runs in vitro release studies for long-acting injectables, hydrogels and microparticles, and records depot mass and drug release on one timeline. Your team sees why a formulation bursts or lags, and takes the right candidate forward.
Discuss a pilot studyThe right depot, chosen sooner, reaching patients faster
One injection that releases for weeks to months can replace daily doses. Clearer release data means fewer dead-end candidates, a stronger case going into animal studies, and better medicines reaching patients sooner.
- 3x
- higher precision than manual methods, so a real difference between formulations stands out.
- Know why it bursts or lags
- See when the depot swelled, set and eroded, so you know what to change.
- A formulation decision sooner
- Testing runs around the clock, nights and weekends, so a candidate is ready for animal studies sooner.
- Fewer surprises in the clinic
- Weeks to months at the temperature and pH you set: closer to in vivo conditions, and a stronger basis for IVIVC.
Depot mass and drug release in one study
A release curve shows how much drug left the depot. It doesn't show when the depot swelled, set or began to erode. Carousel weighs the depot while UV-Vis, one of our integrated instruments, reads the drug in sampled medium.
Swelling/degradation and drug released
Illustrative · one point per automated 24/7 measurement
Illustrative chart of one gel sample's swelling and degradation, as its mass ratio to the initial dry mass, and the cumulative % of its drug released through one test.
Swelling, antimicrobial released and wound pH
Illustrative · one point per automated 24/7 measurement
Illustrative chart of a wound dressing's swelling, as its mass ratio to the initial dry mass, the cumulative % of its antimicrobial released, and the wound bed's pH, neutral to slightly alkaline when fresh (about 7.8) and acidifying toward intact skin's pH (about 5.5) as it heals.
Scaffold swelling/resorption and new tissue
Illustrative · one point per automated 24/7 measurement
Illustrative chart of a hydrogel scaffold in a knee cartilage defect: its mass ratio to the initial dry mass as it swells to press-fit the defect and is then resorbed, and the % of the defect new cartilage has filled.
Swelling, deswelling and biodegradation
Illustrative · one point per automated 24/7 measurement
Illustrative chart of a soil hydrogel's water held per gram through two rains (shaded) and dry spells, then its biodegradation.
Swelling
Illustrative · one point per automated 24/7 measurement
Illustrative chart of a superabsorbent's swelling in a diaper, as its mass ratio to the initial dry mass, through one test.
How a depot releases its drug
Drug leaves a hydrogel or depot three ways, often at once: diffusion through the network, swelling that opens it, and degradation that breaks it down.
| Measurement | What it answers | How it's measured |
|---|---|---|
| In vitro release testing | How fast and how completely the drug leaves. | Sampled medium read by UV-Vis or mass spectrometry. |
| Depot behavior | How the depot takes up fluid, sets and swells. | Carousel weighs hydrated mass from the first minutes. |
| Degradation | When the polymer starts losing mass and erosion starts driving release. | Carousel tracks drained wet mass. ASTM F1635 weighs dry mass at set timepoints. |
Formats and polymers
Resorbable polyesters (PLGA, PLA, PGA, PCL) and natural and synthetic hydrogels (hyaluronic acid, alginate, chitosan, PEG), run from ambient to 60 °C in media from pH 1.5 to 12.
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Injectable depots
Hydrogels and in situ forming depots, injected as a liquid that sets.
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Microparticles
Drug-loaded microspheres, suspended for injection.
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Biodegradable implants
Rods and discs that release as the polymer erodes.
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Oral solids
Tablets, capsules and gastroretentive forms.
Oral solid dosage forms
A swelling tablet's release follows its gel layer, which forms as fluid enters. Carousel tracks swelling and disintegration by mass while UV-Vis reads the drug in the medium, so release can be read against what the tablet is doing.
Dissolution methods are aligned with USP <711>.
What this testing doesn't cover
- Animal and clinical studies. We get a candidate ready for them; we don't run them.
- No accredited biocompatibility, sterility or safety testing.
- The regulatory decision. You receive a documented dataset and report, and your team decides how it supports a submission.
How a release study starts
Get a dataset and report on your own material through a pilot study: ship us your formulation, or have us formulate it, and our R&D services team runs the study. Teams that test often can run the same methods on their own Carousel, with install, training and a 30-day trial.
- 01
Formulation
Yours, or one we develop with you.
- 02
Depot formation
The depot forms in medium at a set temperature and pH.
- 03
Weighing and sampling
Carousel weighs the depot; integrated instruments read the sampled medium.
- 04
Dataset
Depot mass and release data, delivered as a report.
Plan a pilot release study
Send us your formulation and what the study needs to show.