Solubility of Sodium Hyaluronate

The solubility of sodium hyaluronate is the foundation of its application. Solubility not only affects its dispersibility in different solutions but also directly influences its bioavailability and efficacy. The solubility is influenced by various factors, including solvent type, temperature, pH, and the molecular weight of hyaluronic acid.

–How Long Does It Take for Sodium Hyaluronate to Dissolve

The solubility of sodium hyaluronate varies in different solvents. In water, it can dissolve quickly, forming a transparent and viscous solution. In glycerol, its solubility is moderate, though not as high as in water. This is why glycerol and hyaluronic acid are often found together in cosmetics. In ethanol, the solubility of hyaluronic acid is low, and it usually requires mixing with other solvents. In acetone, sodium hyaluronate is almost insoluble and is generally not used in such solvents.

Table 1. A comparison of the solubility of sodium hyaluronate in different solvents:

Stanford Chemical Company (SCC) is a trusted supplier of sodium hyaluronate powder. We provide customers with high-purity, non-animal-derived, non-GMO hyaluronic acid powder (including food grade, cosmetic grade, injection grade, medical grade, eye drop grade, cross-linked gel). Enjoy bulk purchase discounts and contract pricing.

• SDS of Sodium Hyaluronate
• Sodium Hyaluronate production flow chart

–How to Dissolve Sodium Hyaluronate Quickly

In addition to solvent type, several factors influence the solubility of sodium hyaluronate. A previous article discussed this topic in detail. If interested, you can click to read: Solubility of Hyaluronic Acid in Different Solvents and Its Influencing Factors

To accelerate dissolution, the following methods are commonly used:

• Stirring: Mechanical stirring can speed up the dispersion and dissolution of HA in water. The stirring speed and duration significantly affect the dissolution efficiency.
• Heating: Moderate heating (usually not exceeding 60°C) can increase the dissolution rate, but care must be taken to avoid degradation caused by high temperatures. Temperature should be controlled, and prolonged high-temperature treatment should be avoided.
• Premixing: Premixing sodium hyaluronate with a small amount of glycerol or ethanol before diluting with water can improve dissolution efficiency. This method is particularly suitable for preparing high-concentration sodium hyaluronate solutions.

Viscosity of Sodium Hyaluronate

Viscosity is one of the important physical properties of sodium hyaluronate, directly affecting its application in cosmetics and medicine.

–How Viscosity Affects the Efficacy of Sodium Hyaluronate

The viscosity of hyaluronic acid is closely related to its molecular weight. High-viscosity hyaluronic acid forms a protective film on the skin surface, effectively locking in moisture, while low-viscosity sodium hyaluronate penetrates deeper into the skin, providing deep hydration. Viscosity also affects the flowability and distribution uniformity of sodium hyaluronate during injection or application.

–What Factors Affect the Viscosity of HA

Molecular weight, concentration, temperature, pH value.

Higher molecular weight results in higher viscosity. High molecular weight hyaluronic acid has longer molecular chains and stronger intermolecular interactions, leading to higher viscosity.

Higher concentration leads to higher viscosity. In high-concentration sodium hyaluronate solutions, molecules are closer together, resulting in stronger interactions and increased viscosity.

Higher temperatures reduce viscosity. Increased molecular motion at high temperatures weakens intermolecular interactions, causing a decrease in viscosity.

Hyaluronic acid exhibits the most stable viscosity within a pH range of 6-8. Under acidic or alkaline conditions, sodium hyaluronate molecules may undergo hydrolysis or cross-linking, leading to changes in viscosity.

Fig 2. Relationship between the relative viscosity of LMW-HA/HMW-HA aqueous solutions and the HMW-HA content.[1]

Stability of Sodium Hyaluronate

The stability of sodium hyaluronate is another critical factor in its application. Stability not only affects its storage and shelf life but also influences the durability of its efficacy.

The Impact of Temperature on Stability

Hyaluronic acid is prone to degradation at high temperatures, so high-temperature environments should be avoided during storage and use. Typically, sodium hyaluronate is most stable within a temperature range of 4°C to 25°C.

The Impact of pH on Stability

Hyaluronic acid is susceptible to hydrolysis in acidic or alkaline environments, leading to molecular chain breakage. Therefore, maintaining the pH of sodium hyaluronate solutions within the range of 6-8 is crucial for ensuring stability.

The Impact of Light and Oxidation on Stability

Hyaluronic acid is prone to degradation under light and oxidative conditions. Therefore, it should be stored away from light, and antioxidants should be added to extend its stability.

Read more: How to Maintain the Stability of Hyaluronic Acid Products

Table 2 below is a comparison of the stability of HA under different conditions:

[1] Saitarly, Svetlana & Pushkarev, Yuriy & Nesterkina, Mariia & Ozturk, Serhat & Salih, Bekir & Kravchenko, Iryna. (2021). Rheological Properties of Hyaluronic Acid Diluted Solutions as Components of Cosmetics. Biointerface Research in Applied Chemistry. 12. 1907-1915. 10.33263/BRIAC122.19071915.

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What is Hyaluronic Acid

Hyaluronic Acid (HA) is a polysaccharide naturally found in the connective tissues, skin, joint fluid, and eyes of the human body. It has a unique ability to retain water and is an important structural component in living organisms.

Benefits of Hyaluronic Acid

Due to its biocompatibility and versatility, HA is widely used in medicine, cosmetology, and bioengineering.

1. Joint Health

Hyaluronic acid plays a crucial role in joint health as a major component of synovial fluid, which lubricates and cushions the joints. It helps reduce friction between the joints, alleviating pain and improving mobility. This is particularly beneficial for individuals with osteoarthritis, as HA can help relieve symptoms and slow disease progression.

2. Ophthalmic Applications

In ophthalmology, hyaluronic acid is widely used in eye drops to relieve dry eye symptoms, providing long-lasting lubrication and comfort. During eye surgeries, HA is used to protect and repair corneal tissue, accelerate postoperative recovery, and reduce complications.

3. Tissue Repair and Regeneration

Hyaluronic acid promotes tissue repair and regeneration by stimulating cell proliferation and migration, speeding up the wound-healing process. It is beneficial in treating burns, ulcers, and other skin injuries, helping to reduce scar formation and enhance the quality of skin repair.

4. Anti-inflammatory and Immune Regulation

Hyaluronic acid exhibits significant anti-inflammatory and immune-regulating properties. It can reduce the release of inflammatory mediators, lowering inflammation and minimizing tissue damage. Additionally, HA can modulate the immune system, enhancing the body’s defense mechanisms and helping to alleviate chronic inflammatory conditions.

5. Beauty and Skincare

In the field of beauty and skincare, hyaluronic acid is highly prized for its exceptional moisturizing capabilities. It can deeply hydrate the skin, increasing its water content, making it soft, and smooth, and reducing the appearance of fine lines and wrinkles. HA also promotes collagen production, enhancing skin elasticity and firmness, thus improving overall skin quality.

What is Molecular Weight

Molecular weight (MW), also known as relative molecular mass, is the sum of the masses of all the atoms in a molecule. It is used to measure the size of a molecule and is typically expressed in Daltons (Da) or atomic mass units (AMU).

Calculating the MW of hyaluronic acid is complex because it is a high-molecular-weight polysaccharide made up of repeating disaccharide units (glucuronic acid and N-acetylglucosamine). The molecular weight depends on the chain length, i.e., the number of disaccharide units.

Fig 1. Hyaluronic acid chemical structure

In practice, the molecular weight of HA is usually expressed as a range. Low molecular weight HA is less than 200 kDa, medium molecular weight HA ranges from 200 to 1800 kDa, and high molecular weight HA is greater than 1800 kDa. These ranges represent the average number of disaccharide units in HA molecules, not precise single values.

How Molecular Weight Affects Hyaluronic Acid’s Efficacy

The molecular weight of HA significantly influences its biological activity and efficacy.

1. Differences in Viscoelasticity and Lubricity

High molecular weight HA (typically over 1800 kDa) is widely used to treat arthritis due to its excellent viscoelastic and lubricating properties. It enhances the viscosity of joint fluid, reducing friction, pain, and inflammation. This type of HA is usually injected directly into the joint cavity for maximum effect. On the other hand, Medium molecular weight HA (200-1800 kDa) is also used for joint health, often found in oral or injectable supplements. It provides lubrication and cushioning within the joint cavity, improving joint mobility and flexibility.

In ophthalmic surgery, high molecular weight HA is commonly used, such as in cataract surgery and corneal transplants. Its high viscosity and viscoelasticity protect eye tissues, reducing mechanical damage during surgery. Conversely, low molecular weight HA (usually less than 200 kDa) is often used in eye drops. It effectively keeps the eyes moist, alleviating dry eye symptoms and improving eye comfort.

Fig 2. Low molecular weight hyaluronic acid eye drops

2. Different Effects on Wound Healing

Tissue Repair and Regeneration: In tissue engineering and regenerative medicine, high molecular weight HA is often used as a critical component of biomaterials and tissue engineering. Its structure can mimic the natural extracellular matrix, providing support and signals for cells, promoting cell migration, and tissue regeneration. Low molecular weight HA, due to its smaller molecular size, can better penetrate tissues, promoting wound healing and skin repair by activating fibroblasts and keratinocytes, accelerating the tissue regeneration process.

Fig 3. In the process of wound healing, different molecular weight hyaluronic acid has different effects

3. Variations in Anti-inflammatory and Immunomodulatory Effects

Anti-inflammatory and Immune Regulation: The role of HA in anti-inflammatory and immune regulation is also influenced by its molecular weight. Medium molecular weight HA shows certain advantages in anti-inflammatory and immune regulation. It can bind to cell surface receptors, regulating immune responses, and reducing inflammation, and is used to treat inflammatory diseases such as ulcerative colitis and Crohn’s disease. Low molecular weight HA has shown potential in some studies to regulate the immune system and promote antigen presentation, and immune responses, making it promising in vaccine development.

4. Varied Moisturizing Effects

Beauty and Skincare: In beauty and skincare, high molecular weight HA is mainly used for surface hydration in skincare products, forming a protective layer, reducing water loss, and enhancing skin smoothness. In contrast, low molecular weight HA can penetrate deeper into the skin, promoting hydration in the dermis layer, enhancing skin elasticity, and reducing fine lines and wrinkles, providing deeper skincare effects.

Fig 4. Varied Moisturizing Effects of High VS. Low Hyaluronic Acid

Conclusion

In summary, the molecular weight of HA significantly impacts its efficacy in different fields. High molecular weight HA is mainly used in applications requiring viscoelasticity and lubrication, such as joint health and ophthalmic surgery. In contrast, low molecular weight HA, due to its good permeability and biological activity, is more suitable for tissue repair, anti-inflammatory, immune regulation, and deep skin care. Choosing the appropriate molecular weight of HA can maximize its efficacy and meet the needs of different applications.

Stanford Chemical Company (SCC) is a pioneer in the development of hyaluronic acid. In addition to providing customers with food-grade, medical-grade, cosmetic-grade, and injectable-grade hyaluronic acid, we can also provide users with sodium hyaluronate powder with different molecular weights. For more information or specific applications, please visit our homepage.

Related reading:

Comparative Analysis of Hyaluronic Acid with Different Molecular Weights

High VS. Low Molecular Weight Hyaluronic Acid

The post High vs. Low Hyaluronic Acid: How Molecular Weight Affects the Efficacy appeared first on Stanford Chemicals.

Since its discovery, hyaluronic acid (HA) has garnered significant interest from scientists. Despite its simple chemical structure, its biological functions are extensive. Today, hyaluronic acid is widely used in cosmetics to moisturize the skin and reduce wrinkles. In aesthetic medicine, it is used as a dermal filler to add volume to facial wrinkles and hollow areas. In ophthalmic surgery, it serves as a viscoelastic agent for cataract and glaucoma surgeries, providing protection and lubrication for the eyes. In the field of orthopedics, it is used in intra-articular injections to help relieve osteoarthritis for several months. Sodium hyaluronate can be used in different fields such as skin care, medical treatment, and beauty, thanks to the different molecular weights of hyaluronic products.

Hyaluronic Acid Molecular Weight

Molecular Weight of Hyaluronic Acid

–What is the Molecular Weight of Hyaluronic Acid?

Hyaluronic acid (HA) is a naturally occurring polysaccharide molecule found in human tissues. Its molecular weight (M.W) is usually measured in Daltons (Da). The molecular weight of HA can vary greatly, ranging from a few thousand Daltons to several million Daltons. Common hyaluronic products are typically classified into high molecular weight, medium molecular weight, low molecular weight, and oligomeric hyaluronic acid based on their molecular weight.

–Methods for Measuring the Molecular Weight of HA

Gel Permeation Chromatography (GPC): GPC is one of the primary methods for measuring the molecular mass of HA. In this method, the sample is passed through a series of gel columns that separate molecules based on their size. The separated hyaluronic acid molecules are then detected in a detector to determine their molecular weight.

Light Scattering: Light scattering is another commonly used method for measuring the M.W of sodium hyaluronate. In this method, the hyaluronic acid sample solution is exposed to a laser beam, and its M.W is calculated based on the scattering pattern of the molecules.

Viscometry: This method determines the M.W of hyaluronic acid by measuring the viscosity of its solution. The molecular mass of hyaluronic acid correlates with its flow properties in solution, allowing the estimation of M.W through viscosity measurements.

Nuclear Magnetic Resonance (NMR): NMR can also be used to measure the M.W of sodium hyaluronate. By observing the NMR signals of a hyaluronic acid sample in a magnetic field, its molecular weight and molecular structure can be inferred.

Types of Hyaluronic Acid by Molecular Weight

1. High Molecular Weight HA:

• The M.W is higher than 1,800KDa
• Forms a breathable film on the skin surface, locking in moisture and preventing evaporation, providing long-lasting hydration.
• Poor penetration, does not absorb into the skin.

2. Medium Molecular Weight Sodium Hyaluronate:

• The M.W is between 200KDa and 1,800KDa.
• Forms a breathable film on the skin surface, locking in moisture and tightening the skin.

3. Low Molecular Weight Hyaluronic Acid:

• The M.W is between 5KDa and 200KDa.
• Penetrates the dermis layer of the skin, locking in moisture and promoting skin metabolism, making the skin moist, smooth, delicate, and elastic.
• Poor water retention ability on the skin surface.

4. Oligomeric Hyaluronic Acid:

• The M.W is less than 5KDa
• Composed of less than 50 monosaccharide units, with a degree of polymerization of less than 25, it can deeply penetrate the dermis layer.

Table 1 Comparison of HA with Different Molecular Weights

Table 1 compares the differences of hyaluronic acid with different molecular weights from the four dimensions of molecular weight, water solubility, moisturizing effect and durability.

Stanford Chemicals Company (SCC) is at the forefront of hyaluronic acid development, offering sodium hyaluronate powder in various molecular weights. For more information or specific applications, please visit our home page.

Common Applications of Hyaluronic Acid with Different Molecular Weights

There is currently a general view that the biological effects of hyaluronic acid depend largely on molecular mass. In the same way, hyaluronic acid is widely used in different fields depending on its molecular mass.

–Main Applications of High Molecular Weight HA

High molecular weight hyaluronic acid is mainly used in the fields of lubrication and moisturizing. It has strong moisturizing properties and biocompatibility, and is often used in medicine and cosmetics.

• Ophthalmic surgery: High molecular weight hyaluronic acid is often used as a viscoelastic agent in ophthalmic surgery (such as cataract surgery), where it can provide good lubrication and protection.
• Joint lubricant: In the treatment of osteoarthritis, as an intra-articular injection (such as SYNVISC), high molecular mass hyaluronic acid can improve the viscoelasticity of joint fluid, relieve pain and improve joint function.

–Main Applications of Medium Molecular Weight HA

Medium molecular weight hyaluronic acid is mainly used in the field of moisturizing and repairing. It has moderate moisturizing effect and good transdermal absorption, and is widely used in skin care products and medical dressings.

• Skin care products: For example, hyaluronic acid used in facial creams and essences can help the skin retain moisture, enhance skin barrier function, and promote cell regeneration.
• Medical dressings: Medium molecular mass hyaluronic acid is often used in burn and wound dressings to provide a moisturizing environment and promote wound healing.

–Main Applications of Low Molecular Weight HA

Low molecular weight HA is mainly used in the fields of permeability and anti-aging. It has better permeability and biological activity, and can penetrate deeper into the skin to stimulate cell activity.

• Anti-aging products: such as anti-wrinkle essences and eye creams. Low molecular mass hyaluronic acid can penetrate deep into the dermis, promote collagen production, and reduce fine lines and wrinkles.
• Oral supplements: Some oral hyaluronic acid supplements are designed to be absorbed through the intestines to improve skin hydration and anti-aging effects throughout the body.

–Main Applications of Oligomeric Molecular Weight HA

Oligomeric molecular weight HA is mainly used for deep moisturizing and repair. It has very high biological activity, can quickly penetrate the skin, and plays a role in cell repair and immune regulation.

• Deep moisturizing essence: In high-end skin care products, oligomeric molecular mass hyaluronic acid is often used as an active ingredient, quickly penetrating into the bottom layer of the skin to provide deep hydration.
• Regenerative repair products: such as post-traumatic repair cream or post-operative care products, oligomeric molecular mass hyaluronic acid can quickly repair the skin barrier and promote wound healing.

Conclusion

Hyaluronic acid is categorized into high molecular weight, medium molecular weight, low molecular weight, and oligomeric hyaluronic acid based on its M.W. Each type of HA, due to its unique physical and chemical properties, plays a distinct and important role in medicine and skincare products.

The post Comparative Analysis of Hyaluronic Acid with Different Molecular Weights appeared first on Stanford Chemicals.

Hyaluronic acid (HA) has become a popular ingredient in skincare and supplement products due to its hydrating and anti-aging properties. However, hyaluronic acid products have disparity among each other, as they can vary in their molecular weight. High molecular weight hyaluronic acid (HMW-HA) and low molecular weight hyaluronic acid (LMW-HA) are two different types of hyaluronic acid that can be used with their own benefits and drawbacks. In this article, we will explore the differences between HMW-HA and LMW-HA. Hope that you can have a better understanding of hyaluronic acid and choose the perfect HA products for your project.

Hyaluronate-acid-powder

Hyaluronic Acid: Different Molecular Weight

First, let’s define what we mean by molecular weight. In chemistry, molecular weight refers to the mass of a molecule, which is determined by adding up the atomic weights of all the atoms in the molecule. In the case of hyaluronic acid, the molecular weight can vary widely, ranging from as low as 50,000 Daltons to as high as 10 million Daltons.

HMW-HA has a molecular weight greater than 1500K Daltons, much larger than LMW-HA, whose molecular weight is less than 1000k Daltons [1]. There are also Micro hyaluronic acid and mini hyaluronic acid available. Micro HA has a molecular weight range between 5k Daltons and 50k Daltons [2], even lower than mini HA, whose molecular weight range is between 100k Daltons and 1,500k Daltons [3]. Stanford Chemicals Company (SCC) is a leading supplier of hyaluronic acid of different sizes. Send us an inquiry if you are interested.

Related reading: Viscosity, Molecular Weight and Rheological Properties of HA

High VS. Low Hyaluronic Acid: Different Application Areas

LMW-HA is considered more stable than HMW-HA because of its lower tendency to undergo degradation and better oxidation resistance. Besides, LMW-HA could penetrate the skin surface easier with a lower molecular size. In a word, HMW-HA catches water molecules on the surface, while LMW-HA goes deeper underneath.

Both of them are commonly used in the cosmetic field. They are both excessively hydrating and anti-aging. You can find these hyaluronic acid products such as lotions, creams, etc. LMW-HA and HMW-HA are employed to make supplements as well. You can also combine these hyaluronic acids for your dermis and underneath.

High VS. Low Hyaluronic Acid: Different Effects

HMW-HA is valued for its excellent hydration properties and anti-aging effect. It can hold more water and provide better hydration to the skin. It can also create a film-like barrier on the skin, preventing moisture loss and protecting the skin from environmental aggressors. It is often used in skincare products to provide long-lasting hydration, improve skin texture and elasticity, and reduce the appearance of fine lines and wrinkles.

Hydrating Effect

In contrast, LMW-HA is known for its anti-inflammatory benefits, as it can reduce redness, irritation, and inflammation in the skin. LMW-HA can penetrate the skin more easily. Additionally, it can stimulate the production of collagen and elastin, which are essential for cell growth and differentiation.

Inflammation

So, select hyaluronic acid products according to your skincare goals and concerns. If your primary concern is hydration and anti-aging, then HM-WHA may be the better choice for you. On the other hand, if you are dealing with inflammation, redness, or acne-prone skin, then LMW-HA may be the better choice.

Related reading: Health Benefits of hyaluronic Acid for Skin

Caution

It’s important to note that not all HA products will list their molecular weight on the label. If you are unsure which type of HA is used in a product, you can do some research or reach out to the manufacturer for more information.

In addition to molecular weight, other factors can impact the effectiveness of hyaluronic acid products. The concentration of HA, the delivery method, and other ingredients in the product can all affect how well the product works.

Conclusion

In summary, high molecular weight hyaluronic acid and lower molecular weight hyaluronic acid differ in their effects and use areas.

HMW-HA is better for providing hydration and anti-aging benefits for cells on the surface, while LMW-HA is better for reducing inflammation and improving deeper skin texture.

Stanford Chemicals Company has rich experience in the manufacture and sales of high molecular weight, middle molecular weight, and low molecular weight hyaluronic acid. It’s important to choose a product that is well-formulated and suited to your specific skincare needs to ensure the best results. Please check our homepage for more information.

Reference:

[1] Özdemir, H., & Özdemir, Ö. (2018). Hyaluronic acid: A literature review. In K. Schröder, S. S. Suleman, & L. Ahmad (Eds.), Polysaccharides and Nanocarriers for Drug Delivery and Pharmaceutical Applications (pp. 59-73). Springer.

[2] Guo, H., Jiang, Q., Zhang, L., Feng, R., & Li, X. (2018). Micro- and nano-sized hyaluronan: A comparative study of their in vitro uptake and biological activities. International Journal of Biological Macromolecules, 107(Pt A), 683-691. doi: 10.1016/j.ijbiomac.2017.09.026

[3] Papakonstantinou, E., & Roth, M. (2019). Hyaluronic acid: A comprehensive review. Journal of Cosmetic Dermatology, 18(2), 310-317. doi: 10.1111/jocd.12732

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