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This page gives general product and regulatory information only. It is not medical advice and does not describe any clinical procedure.
Short answer
PLGA is poly(lactic-co-glycolic acid), a synthetic copolymer of lactic acid and glycolic acid that breaks down in water by hydrolysis. A 2023 laboratory study describes it as a biodegradable and biocompatible polymer used for scaffolds, nanoparticles, microparticles and implants. “FDA approved” is attached to finished products, not to the raw polymer, as the sections below explain.
Definition and scope
The name describes the structure: a copolymer built from lactic acid (LA) and glycolic acid (GA) units. The ratio of the two is written as LA:GA, for example 65:35, which is the grade studied in the paper cited below. Because the two building blocks can be combined in different proportions, “PLGA” is a family of materials rather than one fixed substance, and a supplier’s ratio is part of what identifies the grade.
Labs and clinic supply teams meet PLGA in three places: as a research material for particles and scaffolds, as a component of drug delivery systems, and, in closely related form, in absorbable surgical sutures. For a wider view of resorbable print materials, see our guide to biocompatible 3D printing materials.
How it degrades in practice
The Ciocilteu et al. study (Current Health Sciences Journal, 2023) reports that the hydrolysis reaction takes place at the ester group in the polymer structure. The acids released can catalyse further hydrolysis and lower the pH of the surrounding medium, a process the authors call autohydrolysis. In the paper’s phosphate-buffered saline (PBS) experiment, a 65:35 PLGA degraded completely in about 40 days. That figure belongs to that polymer and that setup; it is not a general degradation time for PLGA.
Composition and behaviour: what one study reports
| Factor | What the study reports |
|---|---|
| More lactic acid | More hydrophobic polymer, slower degradation and slower release |
| More glycolic acid | The polymer degrades faster |
| Released acids | Can catalyse further hydrolysis and lower the pH of the medium (autohydrolysis) |
| Acidic surroundings | Degradation can be accelerated |
| Loaded active ingredient | Burst release of surface-bound material in the first 7 to 10 days (about 60% in that study), then a slower diffusion and erosion phase |
Every row comes from one in vitro study using one 65:35 polymer, so treat it as a description of direction, not as numbers to plan around.
Related polymers
PLGA sits between two homopolymers: polylactic acid (PLA, all lactic acid units) and polyglycolic acid (PGA, all glycolic acid units). The study’s finding that more glycolic acid degrades faster is the reason the ratio matters when comparing grades. Regulation of sutures uses a different naming convention based on the monomers: 21 CFR 878.4493 covers sutures made from glycolide homopolymers or from copolymers of 90 percent glycolide and 10 percent l-lactide. That composition is a defined suture material, so it should not be read as a rule for PLGA in general. For background on the discipline, see what polymer science covers.
Where it matters for labs, clinics and supply decisions
Absorbable sutures and 21 CFR 878.4493
Under 21 CFR 878.4493, an absorbable poly(glycolide/l-lactide) surgical suture is described as an absorbable, sterile, flexible strand indicated for soft tissue approximation. The regulation says it meets United States Pharmacopeia (U.S.P.) requirements in the “Monograph for Absorbable Surgical Sutures”; it may be monofilament or multifilament, coated or uncoated, undyed or dyed with an FDA-approved color additive, and supplied with or without a needle. It is classified Class II (special controls), and the named special control is FDA’s guidance document “Class II Special Controls Guidance Document: Surgical Sutures; Guidance for Industry and FDA.” Related reading: what a suture is and absorbable vs non-absorbable sutures.
Questions to ask about a PLGA-containing product
- Is the item a finished device, and if so, what regulatory classification and regulation number does the manufacturer give it? (21 CFR 878.4493 is Class II for the suture described above.)
- For an absorbable suture, does the product state that it meets the U.S.P. monograph for absorbable surgical sutures, as the regulation requires?
- Does the listing give the LA:GA ratio or the monomer composition? The study shows the ratio changes degradation behaviour, so grades with different ratios are not interchangeable on that basis alone.
For device context, see what counts as a medical device and FDA guidance on biocompatibility.
Common misunderstandings
“PLGA is FDA approved”
The Ciocilteu paper calls PLGA “FDA approved” and counts fourteen PLGA-based drug delivery systems that, according to the authors, have received FDA approval and are commercially available. The regulation, however, attaches to finished devices: the Class II suture in 21 CFR 878.4493 is a defined product with defined composition and a named special control. Read together, these two sources show that the approvals and classifications concern specific products, so a polymer name alone does not tell you a product’s regulatory status. Check the product, not the polymer.
“PLGA degrades in a fixed time”
The only timing in the cited study is about 40 days for a 65:35 polymer in PBS. The same paper shows the rate depends on the LA:GA ratio and on the acidity of the surroundings.
“Biodegradable means it vanishes harmlessly everywhere”
The study notes that degradation products are acids that can lower local pH. The paper describes this as part of how degradation proceeds; it does not make claims about any individual patient.
FAQ
What does PLGA stand for?
Poly(lactic-co-glycolic acid): a copolymer of lactic acid and glycolic acid.
What does the ratio such as 65:35 mean?
It is the proportion of lactic acid to glycolic acid units. In the cited study, more lactic acid meant slower degradation and more glycolic acid meant faster degradation.
Is PLGA regulated by the FDA?
The FDA regulates finished devices and drug products. For example, 21 CFR 878.4493 classifies an absorbable poly(glycolide/l-lactide) surgical suture as Class II (special controls). That regulation covers that suture, not PLGA as a whole.
What is PLGA used for?
The cited paper lists tissue engineering scaffolds, nanoparticles, microparticles and implants.
Sources
- 21 CFR 878.4493, Absorbable poly(glycolide/l-lactide) surgical suture, https://www.law.cornell.edu/cfr/text/21/878.4493 (date checked: 2026-10-30).
- Ciocilteu et al., “PLGA – The Smart Biocompatible Polimer: Kinetic Degradation Studies and Active Principle Release”, Current Health Sciences Journal 2023;49(3):416-422, doi 10.12865/CHSJ.49.03.15, https://pmc.ncbi.nlm.nih.gov/articles/PMC10832882 (date checked: 2026-10-30).
