| HS Code | 256732 |
| Product Name | LACTEL 75:25 DL-PLG (B6012-1) Biomedical Acid-Terminated PLGA |
| Product Code | B6012-1 |
| Polymer Type | Poly(DL-lactide-co-glycolide) |
| Monomer Composition | 75:25 DL-lactide:glycolide |
| Lactide Stereochemistry | DL (racemic) |
| Terminal Group | Carboxylic acid |
| Grade | Biomedical |
| Inherent Viscosity | 0.55-0.75 dL/g |
| Appearance | White to off-white granules or powder |
| Glass Transition Temperature | Approximately 50-55 °C |
| Solubility | Soluble in chloroform, dichloromethane, and tetrahydrofuran; insoluble in water |
| Storage Condition | Store at -20 °C, desiccated, protected from moisture |
| Cas Number | 26780-50-7 |
| Biodegradation Products | Lactic acid and glycolic acid |
As an accredited LACTEL 75:25 DL-PLG (B6012-1) Biomedical Acid-Terminated PLGA factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | LACTEL 75:25 DL-PLG (B6012-1) is supplied as 1 g in an amber glass vial, nitrogen-flushed and sealed for biomedical use. |
| Container Loading (20′ FCL) | LACTEL 75:25 DL-PLG (B6012-1), a biomedical acid-terminated PLGA, loaded into a sealed 20′ FCL container with secure packing. |
| Shipping | LACTEL 75:25 DL-PLG (B6012-1) is shipped at ambient temperature in a sealed, moisture-resistant container. Not classified as dangerous goods for transport. Upon receipt, store at -20°C, protected from moisture, heat, and light. Handle under inert atmosphere if stored long-term and keep container tightly closed to prevent hydrolysis and degradation. |
| Storage | Store LACTEL 75:25 DL-PLG (B6012-1) in a tightly sealed, moisture-proof container at -20 °C. Protect from light, heat, and humidity. Keep desiccated; use an inert atmosphere (nitrogen or argon) for extended storage. Allow to equilibrate to room temperature before opening to avoid condensation. Avoid repeated temperature cycling and aqueous exposure, since PLGA hydrolyzes readily. |
| Shelf Life | Recommended shelf life is two years from receipt when stored desiccated at -20°C, protected from moisture. |
In microsphere-based sustained-release parenterals, the acid-terminated 75:25 DL-PLG (B6012-1) is introduced as the dispersed organic phase because the terminal carboxyl groups promote faster hydration, higher bulk water uptake, and stronger ionic interaction with basic peptide residues than ester-capped analogues. Aseptic manufacturing is governed by ISO 13485:2016 and ISO 14644-1:2015 Class 5 fill zones, while finished microspheres are evaluated under USP <711> Apparatus 4 for release, USP <787> for subvisible particulates, USP <85> for endotoxin, and ICH Q3C(R8) for residual dichloromethane or ethyl acetate. In a water-in-oil-in-water double-emulsion route, the polymer is dissolved in dichloromethane at 10–20% w/v and the drug is added at a drug:polymer ratio of 1:5 to 1:20 w/w; the primary emulsion is generated with a Silverson L5M-A rotor-stator fitted with a 10 mm dispersion head at 5,000–15,000 rpm for 30–120 s and then transferred into an aqueous continuous phase containing 0.1–0.5% w/v polyvinyl alcohol. Solvent evaporation proceeds at 2–8°C for 3–6 h, after which the hardened microspheres are collected by centrifugation, washed, wet-sieved through 25 µm and 75 µm screens, and lyophilized with 2–5% w/w mannitol as a cryoprotectant. The terminal finished product is a sterile, off-white lyophilized powder filled into Type I glass vials for reconstitution as an injectable suspension. Because the acid terminus accelerates water ingress, the initial release phase is typically higher than an equivalent ester-capped PLGA; gamma irradiation above 25 kGy is not recommended unless the resulting molecular-weight loss has been quantified by intrinsic viscosity against the certificate of analysis.
For resorbable interference screws, suture anchors, and craniofacial tacks, injection molding of acid-terminated 75:25 PLG is limited by a narrow thermal processing window: the polymer must be sufficiently molten to fill micro-scale mold features, but residence above 170°C accelerates chain scission and shortens post-implantation mechanical retention. Pre-drying is mandatory at 40°C under vacuum below 10 mbar until residual moisture reaches ≤0.05% w/w; melt processing is performed on a micro-molding machine with barrel zones from 140°C to 170°C, injection pressures of 800–1,500 bar, mold temperature of 25–45°C, and total residence time under 5 min. Compliance for the formed device includes ISO 13485:2016, ASTM F1635-16 for in vitro degradation of hydrolytically degradable polymers, ISO 15814:1999 for copolymer degradation testing, and ISO 10993-5:2009 for cytotoxicity. Formulation addition ratio: the polymer may be molded unfilled, or 10–30 wt% β-tricalcium phosphate may be compounded to buffer acidic degradation products and improve osteoconductivity; if intraoperative visibility is required, 5–10 wt% barium sulfate is dispersed as a radiopacifier. The production route uses a twin-screw extruder with L/D 30:1 for compounding, followed by pelletization, micro-injection molding, and trimming; regrind is limited to a single pass because reprocessing depresses the intrinsic viscosity of the acid-terminated polymer and increases variability in degradation rate. The terminal finished product is an ethylene-oxide-sterilized bioresorbable screw or anchor packaged in foil-sealed pouches, with lot release requiring melt viscosity measurement under ASTM D3835-16 and residual moisture verification before molding.
During electrospinning of acid-terminated 75:25 DL-PLG into nonwoven scaffolds for soft-tissue repair, the free carboxylic acid terminus reduces the solution conductivity threshold at which bead-free fiber formation occurs and provides surface carboxyl groups without additional plasma treatment. The polymer is dissolved at 10–15% w/v in 1,1,1,3,3,3-hexafluoroisopropanol or in a chloroform:N,N-dimethylformamide 80:20 v/v blend; the solution is fed at 0.5–2.0 mL/h through a 21–27 G blunt needle with an applied voltage of 18–25 kV and a tip-to-collector distance of 15–25 cm. Fibers are deposited onto a rotating mandrel at 100–500 rpm or onto a grounded flat collector, then vacuum-dried at 40°C under 10 mbar for 24 h to reduce residual HFIP or chloroform below ICH Q3C(R8) limits. Compliance for these devices is established through ISO 10993-5:2009, ISO 10993-10:2010, ASTM F2150-13 for biomaterial scaffold characterization, and ISO 10993-23:2021 for irritation. Addition ratio: the PLG may be used at 100%, or blended with 5–15 wt% gelatin or collagen to moderate hydrophobicity and increase cell attachment; the acid terminus is retained to provide surface carboxyl groups without additional wet-chemical treatment. Terminal finished products include tubular vascular grafts, dura mater substitutes, and wound-contact matrices supplied in sterile double-peel pouches. The principal operational boundary is hygroscopic uptake: solutions prepared under relative humidity above 60% produce inconsistent fiber diameter and bead formation, so solvent preparation and electrospinning are conducted under dry nitrogen purge.
Ultrasonic spray coating of acid-terminated 75:25 PLG onto bare-metal or cobalt-chromium stent platforms yields a conformal drug matrix when the polymer-to-drug ratio and total solids concentration are controlled within narrow limits. The coating solution is prepared at 0.5–2.0% w/v total solids in acetone or a tetrahydrofuran:acetone blend, with a polymer:drug ratio of 1:1 to 2:1 w/w; the antiproliferative drug is applied at 1–3 µg/mm² of stent surface. Deposition is performed with an ultrasonic nozzle at 0.8–2.5 W, flow rate 0.05–0.2 mL/min, nozzle-to-stent distance 8–15 mm, and drying gas temperature of 50°C; the target coating thickness is 5–12 µm with total coating mass of 500–800 µg/cm². Compliance for this product class includes ISO 25539-2:2020 for vascular stents, ISO 10993-1:2018 for biological evaluation, USP <788> for particulate matter, and ICH Q3C(R8) for residual acetone and tetrahydrofuran. Addition ratio: the acid-terminated PLG is selected when faster post-deployment drug release is required, as the carboxylic acid groups accelerate polymer hydration relative to ester-capped PLG. Process controls include in-line coating mass measurement and visual inspection for webbing; the coated stent is annealed at 45°C for 12–24 h under vacuum before crimping onto the delivery balloon. Terminal finished products are drug-eluting coronary or peripheral stents in sterile barrier packaging. The operational boundary is the low glass transition of the 75:25 PLG: storage above 30°C may induce film tackiness and coating delamination during balloon expansion.
When injected subcutaneously or into periodontal pockets, a flowable solution of acid-terminated 75:25 DL-PLG in N-methyl-2-pyrrolidone forms a solid depot by solvent exchange and entraps the dispersed drug. The polymer is dissolved in N-methyl-2-pyrrolidone at 30–50% w/w under dry nitrogen at 40–60°C; the active pharmaceutical ingredient is added at 1–10% w/w of the final formulation, and the resulting solution exhibits viscosity from 0.5 Pa·s to 2.0 Pa·s at 25°C, which governs syringeability through 21–23 G needles. The manufacturing line includes a jacketed glass reactor, a 0.22 µm sterilizing filter, and an aseptic filling isolator; the finished product is a pre-filled single-dose syringe or a two-syringe mixing system. Compliance is addressed by ISO 10993-6:2016 for local effects after implantation, ISO 10993-11:2017 for systemic toxicity, USP <788> for particulate matter, and ICH Q3C(R8) for residual N-methyl-2-pyrrolidone. The terminal product class is an injectable in-situ forming depot for sustained systemic or local delivery. The acid terminus of B6012-1 increases water uptake relative to ester-capped PLG, which shortens the lag phase but may also increase initial drug release; therefore, formulation studies with the actual drug and target injection volume are required because published data for this specific configuration is limited. Pre-clinical depots are characterized by mass loss and molecular weight decline under ISO 15814:1999 to distinguish bulk erosion from surface erosion, and release testing is performed in phosphate-buffered saline at 37°C under USP <711> Apparatus 4.
Solvent casting of acid-terminated 75:25 PLG into resorbable barrier membranes for guided tissue regeneration requires low-humidity drying and controlled polymer concentration to avoid surface skinning that traps residual solvent. The polymer is dissolved in dichloromethane or a dichloromethane:ethanol 85:15 v/v mixture at 15–25% w/v; where osteoconductivity is desired, 10–20 wt% hydroxyapatite or β-tricalcium phosphate is dispersed with a high-shear mixer at 3,000–6,000 rpm before casting. The solution is drawn with a knife-over-roll coater onto a PTFE-coated plate at a wet thickness of 200–600 µm, dried at 25–30°C for 8–12 h, and then vacuum-dried at 40°C to reduce residual dichloromethane below the ICH Q3C(R8) limit. Compliance testing uses ISO 10993-5:2009, ISO 10993-10:2010, ASTM D882-18 for tensile properties of thin plastic sheeting, and ASTM F1635-16 for in vitro degradation; the finished membrane is sterilized as a single-use device under ISO 11135:2014. The terminal product is a resorbable periodontal or dental barrier membrane, typically 0.2–0.5 mm thick, cut into 20 mm × 25 mm or 30 mm × 40 mm formats. The acid terminus is retained to promote moderate hydrophilicity and in situ expansion without the use of migratory plasticizers; however, published data for B6012-1 solvent-cast membrane barrier performance is limited, and batch-to-batch variation in crystallinity after solvent evaporation is controlled by fixed cooling rates, differential scanning calorimetry at 10°C/min, and residual solvent measurement by headspace gas chromatography.
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Lactel 75:25 DL-PLG (B6012-1) Biomedical Acid-Terminated PLGA is an absorbable copolymer of DL-lactide and glycolide in a 75:25 molar ratio, with free terminal carboxylic acid groups rather than ester-capped chain ends. The B6012-1 product code distinguishes the acid-terminated member of the 75:25 DL-PLG series from ester-capped analogues of equivalent comonomer ratio. The polymer is amorphous because the racemic DL-lactide repeat unit suppresses stereoregular crystallization, and it is supplied as a solid resin intended for dissolution in chlorinated or polar aprotic solvents for drug encapsulation, microsphere fabrication, implant coating, electrospinning, or absorbable device component manufacture. The raw material is not a finished medical product; chemical characterization, residual impurity control, and biological evaluation are therefore managed under ISO 10993-18:2020 and pharmacopeial methods appropriate to the intended use.
Product selection typically begins with the acid-end-group chemistry rather than the comonomer ratio alone. Ester-capped 75:25 DL-PLG carries alkyl ester chain termini, whereas B6012-1 presents ionizable carboxylic acid groups. The difference alters early water uptake, interfacial pH, and ionic interaction with peptide or protein cargo during encapsulation. DL-lactide rather than L-lactide prevents the crystalline domains observed in poly(L-lactide) homopolymer and provides a lower glass transition temperature and faster hydrolytic degradation than semicrystalline poly(L-lactide). Relative to 50:50 DL-PLG at equivalent molecular weight, the 75:25 ratio reduces glycolide repeat-unit density and slows hydrolytic chain scission; relative to 85:15 DL-PLG, the 75:25 ratio shortens the expected resorption window under identical device geometry and porosity.
The free acid terminus is not a passive structural detail. In aqueous environments, carboxylic acid end groups raise local chain hydrophilicity and can lower interfacial pH, which accelerates ester-bond hydrolysis during the early degradation phase before autocatalytic bulk erosion dominates. The ester-capped equivalent lacks this initial ionizable end-group population and hydrates more slowly under identical geometry, molecular weight, and temperature. Published in vitro hydrolysis studies in phosphate-buffered saline at 37 °C and pH 7.4 show that degradation rate is not determined solely by end-group chemistry; molecular weight, specimen thickness, porosity, buffer exchange, and local accumulation of lactic and glycolic acid can dominate the observed mass-loss profile.
The acid end group also creates a handling boundary that is less prominent in ester-capped grades. The terminal carboxylic acid can form ionic complexes with amine-containing peptides and proteins, which may increase encapsulation efficiency but also change release kinetics and reduce the free fraction of basic drug during early release. Formulations containing acid-labile active ingredients or amine-functional excipients should therefore be evaluated for ionic precipitation, salt formation, or pH-driven degradation before committing to a solvent-evaporation or spray-drying process. The 75:25 ratio is selected when slower degradation than 50:50 DL-PLG is required but 85:15 DL-PLG would persist beyond the target resorption window; however, terminal acid groups on B6012-1 can narrow that window relative to ester-capped 75:25 DL-PLG under identical processing history.
In aqueous environments at 37 °C and pH 7.4, water uptake by the amorphous 75:25 DL-PLG matrix precedes ester-bond cleavage. The glass transition temperature reported in the literature for 75:25 PLGA is commonly in the range of 45–50 °C, depending on molecular weight and residual solvent; absorbed water plasticizes the matrix and lowers the effective Tg below the incubation temperature, increasing chain mobility and hydrolysis rate. Hydrolytic degradation produces lactic acid and glycolic acid. In thick implants or large microspheres, acidic byproducts cannot diffuse out rapidly, producing internal autocatalysis and faster core degradation than surface erosion. B6012-1 adds an additional carboxylic acid source at the chain termini, which can contribute to this autocatalytic process during early hydration. The resulting heterogeneous degradation is a critical processing consideration for microsphere release testing and implant mechanical integrity.
The B6012-1 standard grade is commonly specified with an inherent viscosity range of 0.55–0.75 dL/g when measured in chloroform at 25 °C and 0.1 g/dL, with the exact value reported on each lot certificate of analysis. Size-exclusion chromatography with refractive index or multi-angle light scattering in hexafluoroisopropanol or tetrahydrofuran is used to characterize number-average molecular weight, weight-average molecular weight, and dispersity. Acid termination can be confirmed by titration of carboxylic acid content or by end-group analysis using 1H NMR. Residual lactide and glycolide monomers are controlled because unreacted monomer can migrate and contribute to local irritation or plasticization. Residual process solvents such as dichloromethane or ethyl acetate are measured by headspace gas chromatography under USP <467> protocols. Tin residues from stannous octoate catalyst are quantified by inductively coupled plasma mass spectrometry because tin is used in the ring-opening polymerization of lactide and glycolide.
The material should be stored in moisture-barrier packaging under refrigeration or frozen conditions typical for absorbable polyesters, and the package should be equilibrated to ambient temperature before opening to avoid condensation. A maximum moisture content of 0.5 wt% by Karl Fischer titration is frequently used as the pre-drying target before melt processing, because residual moisture accelerates hydrolytic chain scission at elevated temperature. Biocompatibility screening of the raw polymer may be carried out using ISO 10993-5:2009 cytotoxicity testing, but finished-device biological evaluation under ISO 10993-1:2018 is still required because processing aids, sterilization, and degradation products can alter the final biological response.
| Parameter | Method or standard | Technical relevance |
|---|---|---|
| Chemical identity | ISO 10993-18:2020; FTIR, NMR | Confirms DL-lactide/glycolide ratio and acid end-group character |
| Inherent viscosity | ISO 1628-1:2021; capillary viscometry | Controls molecular weight and lot-to-lot processing consistency |
| Residual monomers | ISO 10993-13:2010; HPLC | Limits lactide and glycolide burden in biomedical intermediates |
| Residual solvents | USP <467>; headspace GC | Controls solvent residues after microsphere or film processing |
| Tin catalyst residue | ISO 10993-18:2020; ICP-MS | Quantifies residual tin from stannous octoate catalyst |
| Cytotoxicity screening | ISO 10993-5:2009 | Raw-material screening; finished-device testing remains mandatory |
For emulsion-based encapsulation of water-soluble peptides or proteins, B6012-1 is dissolved in an organic phase such as dichloromethane or ethyl acetate at concentrations commonly between 1% and 20% w/v, depending on target microsphere size and solution rheology. The aqueous drug solution or suspension is dispersed into the organic phase by rotor-stator homogenization to form a water-in-oil emulsion; this primary emulsion is then transferred into an external aqueous poly(vinyl alcohol) phase to form a water-in-oil-water emulsion. Droplet size is measured by laser diffraction per ISO 13320. Particle size is controlled primarily by impeller tip speed, continuous-phase viscosity, and external-phase stabilizer concentration; tip speed rather than impeller speed is the usual scale-up variable in rotor-stator emulsification. After solvent extraction or evaporation, the microspheres are washed, filtered, and lyophilized. Residual moisture after lyophilization is measured by Karl Fischer titration per ISO 15512 or an equivalent pharmacopeial method. For organic-soluble actives, a single oil-in-water emulsion may be used. The polymer solution should be filtered through a 0.2 µm membrane to reduce bioburden before aseptic processing.
The acid terminus exerts the strongest processing and stability influence during early aqueous exposure. In dilute solution or high-surface-area microspheres, free carboxylic acid end groups can increase water uptake and catalyze ester hydrolysis, so molecular weight may decline faster during the first 24–72 h than an ester-capped analogue of equivalent comonomer ratio and molecular weight. This is relevant to formulations that are terminally sterilized by gamma irradiation or exposed to moisture during lyophilization or delayed packaging. Irradiation can induce chain scission and free-radical reactions that increase carboxylic acid content and reduce melt viscosity. Published irradiation data for this specific B6012-1 configuration is limited; dose mapping and post-irradiation inherent-viscosity or size-exclusion chromatography testing are therefore required. If gamma sterilization is selected, dose establishment follows ISO 11137-1:2006 and ISO 11137-2:2013, and the molecular-weight shift must be characterized for each lot and irradiation configuration.
The acid end groups can interact with amine-containing cationic peptides through ionic complexation. This may improve encapsulation efficiency by retaining peptide in the polymer phase, but it can also delay release or alter the local pH within the degrading microsphere. In PLGA microspheres, the internal pH microenvironment can become acidic during bulk erosion, and acid-labile proteins may lose activity if not protected by buffering excipients. B6012-1 should be considered in that context because the terminal carboxyl groups are part of the same acidic microenvironment. Formulations containing amine-functional additives should be evaluated for premature ionic association with the polymer chain ends, which can alter emulsion stability and drug distribution.
In melt extrusion of B6012-1 on a twin-screw extruder with L/D ratio from 25:1 to 40:1, pre-drying to a low moisture specification is required before processing. A vacuum oven or desiccant-dry-air dryer is used because moisture-driven hydrolysis at barrel temperature can reduce intrinsic viscosity during compounding. Extruder barrel temperatures are frequently profiled downward from the feed throat to the die to limit thermal history, and processing above 120 °C can produce measurable intrinsic-viscosity loss in the presence of residual moisture or prolonged residence time. A vented extruder under vacuum removes volatile residual solvents and moisture. Because B6012-1 is amorphous, strand cooling and pellet cutting may require lower die temperatures and faster cooling than semicrystalline biodegradable polymers to prevent sticking or strand breakage. Steam autoclaving is generally incompatible with this polymer because hydrolytic degradation accelerates under saturated moisture and high temperature; terminal sterilization by gamma irradiation may be used only after validation of molecular-weight retention and degradation product formation at the selected dose.
