Study brief and scoping checklist for biomaterials testing
A study brief answers eight questions: the decision, the material and formulation, the sample format and count, the medium, the conditions, the duration and timepoints, the readouts, and the outputs and deadline. You don’t need any confidential formulation detail to start a scoping conversation. Fill in what you know, and mark the rest as open.
What goes in a study brief?
A study brief states what you need to decide and what the study has to look like to decide it. Copy the table into your own document and fill in the right-hand column. An “open” is a useful answer, since it tells the lab what to bring to the call.
| Item | The question it answers | Your answer |
|---|---|---|
| 1. Decision | What will you do differently once you have the result, and who decides? | |
| 2. Material and formulation | What class of material is it, and is it made already or still to be formulated? | |
| 3. Sample format and count | What form does it take, how much of it is there per sample, and how many formulations and lots? | |
| 4. Medium | What fluid does the material meet, and does it contain surfactant, enzyme or a preservative? | |
| 5. Conditions | What temperature, pH, pressure and flow? | |
| 6. Duration and timepoints | How long, and where does the behavior you care about happen? | |
| 7. Readouts | What has to be measured, and on what basis (wet mass, dry mass, drug in the medium)? | |
| 8. Outputs and deadline | Who reads the result, in what format, and by when is the decision due? |
The brief is the first step in how a biomaterials pilot study works.
What can you leave out until an NDA is in place?
You can leave out anything that would let someone reproduce your formulation. GelTech’s terms ask you not to send formulations, compositions or unpublished data through the site or by email until a confidentiality agreement is in place, and say that information sent before then isn’t covered by one. A useful first brief doesn’t need them.
| Share at first contact | Hold until an agreement is in place |
|---|---|
| Material class, such as “a crosslinked hydrogel” or “a resorbable polymer depot” | Exact composition, ratios and concentrations |
| Type of active, such as “a small molecule” or “a peptide” | Drug identity and loading |
| Sample format and rough size | Process parameters and crosslinking chemistry |
| Medium type, temperature and intended duration | Unpublished data and prior results |
How do you write the decision and the material?
Write the decision first, as a choice with two outcomes, because every other item depends on it. ICH’s Q8(R2) says the quality target product profile “forms the basis of design” for a product’s development. “Characterize our gel” gives a lab nothing to design around. “Choose between two crosslink densities for a dressing that has to hold fluid under load” does.
For the material, write down lots along with the name. Fu and colleagues found that ten batches of one pharmaceutical grade of sodium alginate differed in rheological properties, so a polymer’s name doesn’t tell a lab which material it’s testing.
How do you choose the medium and conditions?
Choose the medium and conditions that match the question, then write down why, since published methods differ more than you’d expect. A 2026 review of PLGA long-acting injectables tabulates FDA database entries that range from phosphate-buffered saline with 0.02% Tween 20 at 37 °C to 0.3% SDS in phosphate buffer at 35 °C.
The same review reports that testing is generally done at 37 °C for intramuscular or subcutaneous products, and that variations of ±0.5 °C changed release profiles from commercial risperidone microspheres. Other material classes may be less sensitive. Either way, write a tolerance beside the set point.
Name your reason for each choice in a word or two: “matches the pharmacopoeial setup”, “physiological”, “needed for solubility”. A surfactant added for solubility changes what the material sits in, and that’s a trade-off the brief should show.
How do you set the duration and timepoints?
Set the duration by the slowest behavior the decision depends on, and bunch the timepoints where the material changes fastest. The review notes that real-time testing of long-acting products takes weeks or months, and that burst, lag or secondary phases may shrink or disappear under accelerated conditions. If you plan a shorter accelerated run, say so, and expect a real-time comparison to go with it.
Burst behavior happens early, so a schedule that starts at 24 hours can miss it. Initial burst release covers that case. If you want a swelling ratio, say so under readouts: Caria and colleagues describe it as the difference between swollen and dry weight divided by dry weight, so the study needs a dry weight from somewhere. The hydrogel swelling ratio goes further.
What should you check on the samples before they ship?
Check that the lab can tell what state each sample was in, and what happened to it before it arrived. Tick these off for every formulation.
- Lot and supplier: recorded for every raw material, including the polymer.
- Preparation date: recorded per batch, with the sample’s age at shipping.
- Sterilization state: stated as sterile or not, and by which method. In one 2026 study of silk fibroin hydrogels, gamma irradiation and autoclaving increased stiffness and ethylene oxide compromised the mechanics. Test the state your product will be in, if you can.
- Storage: temperature, light and time recorded. The same study stored its hydrogels at 4 °C and tracked how their structure changed.
- State at test: dry, hydrated, or a liquid that sets in the medium, with any syringe, needle or mixing step written down.
- Sample mass or size: enough per sample for the method. Carousel’s minimum is 25 mg dry mass.
- Homogeneity: mixed, and free of air bubbles. Sinan’s newsletter on commercialization cites a protocol that lists bubbles, incomplete mixing and sample loading among the things that shift rheology results.
- Particle size: noted for microparticles and powders, so the lab can pick a filter that holds them back.
- Filter compatibility: flagged if your active may stick to plastics. The review says a filter used in release sampling shouldn’t adsorb the drug.
- Blanks: a placebo or active-free sample, if the study reads drug in the medium.
- Assay and standard: the analytical method and reference standard for your active, if you have them.
- Hazards: a safety data sheet, plus any cells, biologics or sensitive actives named.
- Shipping and leftovers: most samples ship at room temperature, so flag a sample that needs a cold shipment. Say whether you want leftover material sent back, or GelTech disposes of it.
What can’t a study brief settle?
A study brief can’t settle whether a method will work on your material, which is what a pilot is for. The 2026 review states there are currently no standard compendial in vitro release methods for long-acting injectables, so for that class some of the method has to be worked out against the sample itself. Expect some answers in the brief to change on the scoping call.
Compare options before you commit to one: outsourcing a study or buying an instrument and choosing a testing partner both start from the same answers.
What does GelTech do with a study brief?
GelTech uses a brief to scope a study on a call, then sends a formal quote. The Carousel spec sheet sets the limits to check your answers against:
- Samples: 25 mg minimum dry mass, 100 g maximum load, six at once per unit.
- Chamber and flow: a 24 mL sample chamber inside a 50 mL incubation chamber, and 5 to 150 mL/min of flow.
- Conditions: ambient to 60 °C, media from pH 1.5 to 12, and 0.1 to 1 PSI.
- Filters: 0.1 to 1,000 µm, in polypropylene, nylon or PTFE.
Release, rheology and chemistry come from integrated instruments on GelTech’s R&D services menu. GelTech doesn’t run animal or clinical studies or accredited biocompatibility or sterility testing.
Sources
- FDA and ICH. Q8(R2) Pharmaceutical Development, guidance for industry, November 2009
- Fu S, Thacker A, Sperger DM, et al. Rheological evaluation of inter-grade and inter-batch variability of sodium alginate. AAPS PharmSciTech. 2010;11(4):1662-1674
- Lusina Kregar M, Krtalić I, Šagud I. An overview of in vitro release methods for long-acting injectable products based on PLGA. Methods Protoc. 2026;9(3):87
- Busatto CA, Callone E, Di Chio M, et al. Effect of sterilization methods on the physicochemical properties of silk fibroin hydrogels. Polymers. 2026;18(13):1625
- Caria S, Petiti J, Picollo F, Divieto C. Strategies and technologies for comprehensive characterization of hydrogel-based materials in the biomedical field. Polymers. 2026;18(15):1805
- GelTech Labs, R&D services page
- GelTech Labs, Carousel page and spec sheet
- GelTech Labs, terms of use, confidential information and ideas
Related reading
Questions
Do I need all eight items before contacting a lab?
A study brief doesn't need all eight items before first contact. GelTech Labs asks for two to start: the material and what the data needs to show. The scoping call works through the rest.
Who should write a study brief?
A study brief usually starts with the bench scientist, who knows the sample and the method, and the R&D lead then checks the decision and the deadline. Bring quality in early when the buyer is regulated.
What if I don't have samples yet?
A team without samples can still send a study brief, because GelTech Labs can formulate the material. In that case the material item names the target properties the formulation has to hit.
