Description
Sterile, non-pyrogenic viscoelastic fluid containing hylan A and B polymers produced from a highly purified avian extract. Hylans are hyaluronate derivatives (sodium salt of hyaluronic acid) and consist of repeating disaccharide units of N-acetylglucosamine and sodium glucuronate. Hylan A has an average molecular weight of approximately 6,000,000 daltons and hylan B is a hydrogel. Hylan G-F 20 contains hylan A and B (8.0 mg ± 2.0 mg per ml) in buffered physiological sodium chloride solution (pH 7.2 ± 0.3).
Hylan G-F 20 is biologically similar to hyaluronate. Hyaluronate is one of the components of synovial fluid and determines its viscoelastic characteristics. The mechanical (viscoelastic) properties of Hylan G-F 20 are, however, superior to those of synovial fluid and those of hyaluronate-based solutions of similar concentration.
Hylan G-F 20 has an elasticity (storage modulus G f) at 2.5 Hz of 111-13 Pascal (Pa) and a viscosity (loss modulus G h) of 25-2 Pa. The elasticity and viscosity of knee synovial fluid in subjects aged between 18 and 27 years, measured with a comparable technique, at 2.5 Hz are respectively G L = 117-13 Pa and G. = 45-8 Pa. Hylans are physiologically metabolized through the same process as hyaluronates and the decomposition products are non-toxic.
Hylan G-F 20:
- temporarily restores the viscoelasticity of the synovial fluid;
- provides clinical benefits to patients at all stages of joint osteoarthritis;
- is more effective in patients who actively and regularly use the affected joint;
- achieves its therapeutic effect through viscosupplementation, a process through which the physiological state and rheological characteristics of the synovial fluid of the osteoarthritic joint are restored.
Viscosupplementation with Hylan G-F 20 is indicated to relieve pain and functional limitations, allowing for greater joint movement. In vitro studies have shown that Hylan G-F 20 protects cartilage cells from damage due to physical and chemical agents.
Synvisc is indicated only for intra-articular use by a physician for the symptomatic treatment of pain associated with osteoarthritis of the knee, hip, ankle, and shoulder.
Synvisc-One is indicated only for intra-articular use by a physician in the treatment of pain associated with knee osteoarthritis.

Directions for use
- Remove synovial fluid or effusion before each Hylan G-F 20 injection. - Inject at room temperature. - To remove the syringe from the blister (or container), hold it firmly by the body without touching the plunger rod. - Administer using strictly aseptic procedures, paying particular attention to the removal of the tip. - Unscrew the tip before pulling it out, to minimize product leakage. - Use appropriate needle sizes: • Synvisc – 18 to 22 gauge (use a needle of appropriate length for the joint to be treated);
• Synvisc-One – 18 to 20 gauge (to ensure a perfect seal and prevent leakage during administration, make sure the needle is firmly attached to the syringe).
- Do not overtighten or apply excessive pressure when attaching the needle or removing the needle guard, as this could break the tip of the syringe.
- Inject only into the synovial space, performing the operation under instrumental guidance if necessary, e.g., fluoroscopy, especially when treating the hip and shoulder.
- The contents of the syringe are for single use. The recommended dosage guidelines indicate injecting the entire volume (2 ml for Synvisc and 6 ml for Synvisc-One) of the syringe. Discard unused Synvisc/Synvisc-One.

Knee osteoarthritis
Synvisc
The recommended treatment regimen for Synvisc is three 2 ml injections into the knee, one week apart. To achieve optimal effect, it is essential to administer all three injections. The maximum recommended dosage is six injections over six months, with a break of at least four weeks between treatment regimens.
Synvisc-One
The recommended treatment regimen for Synvisc-One is a single 6 ml injection into the knee, which can be repeated after six months if justified by the patient's symptoms.
Hip, ankle, and shoulder osteoarthritis
Synvisc
The recommended initial treatment regimen is a single 2 ml injection. However, a second 2 ml injection is recommended if adequate symptomatic pain relief is not achieved. Clinical data have shown that patients benefit from this second injection if administered one to three months after the first.

Components
Each ml contains: hylan 8.0 mg, sodium chloride 8.5 mg, disodium hydrogen phosphate 0.16 mg, sodium dihydrogen phosphate hydrate 0.04 mg, water for injections q.s.

Warnings
- Hylan G-F 20 should not be injected into the joint in the presence of venous or lymphatic stasis in the affected limb.
- Hylan G-F 20 should not be used in the presence of infections or severe inflammations or dermatoses or skin infections in the injection area.
- Hylan G-F 20 should not be used in patients with known hypersensitivity (allergy) to hyaluronate-based preparations (sodium hyaluronate).
- Do not inject intravascularly.
- Do not inject extra-articularly or into tissues or the synovial capsule. In general, complications in the injection area have been caused by extra-articular spread of Synvisc.
- Do not use disinfectants containing quaternary ammonium salts for skin preparation, as hyaluronate may precipitate in their presence.
- Hylan G-F 20 should not be used if a significant intra-articular effusion has occurred before injection. - As with all invasive joint procedures, it is recommended that the patient avoid any excessive motor activity after intra-articular injection, and resume full activity within a few days.
- Hylan G-F 20 has not been tested in pregnant women or in children/adolescents under 18 years of age.
- Hylan G-F 20 contains small amounts of avian protein and should not be used in patients with hypersensitivity to this protein.
- Do not use Hylan G-F 20 if the package is open or damaged.
- Do not reuse the syringe and/or needle. Reuse of syringes, needles, and/or product from a used syringe may lead to loss of sterility, contamination of the product, and/or incomplete treatment.
- An ionic or non-ionic contrast agent can be used under fluoroscopic guidance. Do not use more than 1 ml of contrast agent per 2 ml of Hylan G-F 20.
- Do not re-sterilize Hylan G-F 20.

Storage
The contents of the syringe must be used immediately after opening the package.
Store at a temperature between 2 ° C and 30 °C. Do not freeze.

Format
Synvisc is supplied in a 2.25 ml glass syringe pre-filled with 2 ml of Hylan G-F 20.
Synvisc-One is supplied in a 10 ml glass syringe pre-filled with 6 ml of Hylan G-F 20.

Code 002420