FAQ's

Asha Cellulose (I) Pvt Ltd Company manufactures and markets many different ASHACEL® products to accommodate the needs of customers for different physical properties, uses, viscosities, and solubilities.

ASHACEL® polymers are white granular powders with a bulk density of approximately 0.4 g/cm 3. The differences in physical properties of ASHACEL® polymers result largely from variation in ethoxyl content. 0.3 to 0.4 g/cc

ASHACEL® polymers are produced in two ethoxyl types ( M and H) that cover the range of the most useful ethoxyl content. "M" polymers have an ethoxyl content of 48.0 to 49.5%; and "H" polymers have an ethoxyl content of minimum 49.6 % .

ASHACEL® polymers are also produced and marketed in a number of different viscosities. Viscosity increases as the length of the polymer molecule increases.

"M" and ''H'' ethoxyl types are available in various grades useful in regulated as well as industrial application refers to the table below These grades are designed to meet the requirements of pharmaceutical applications.

a Majewicz, T.G., et al., eds., “Cellulose Ethers,” Encylopedia of Polymer Science and Technology, John Wiley & sons, Inc., New York, 2002.

ASHACEL® ethylcellulose polymers are derived from cellulose, which is a naturally occurring polymer. Hence, these polymers have cellulose backbone. The molecule has a structure of repeating anhydroglucose units. Note that each anhydroglucose unit (ring) has three reactive -OH (hydroxyl) sites.

Cellulose is treated with an alkaline solution to produce alkali cellulose, which is subsequently reacted with ethyl chloride, yielding crude ethylcellulose.

ASHACEL® is a trademark of Asha Cellulose (I) Pvt Ltd Company for its family of thermoplastic cellulose ethers. These polymers have provided excellent service to industry since their commercial introduction in the mid-1970s. 1990s Production of Ethyl cellulose

These multifunctional, water-insoluble, organo-soluble polymers are used in many pharmaceutical and specialty applications. They function as binders; tough, flexible film formers; masking and time-release agents; water barriers; and rheology modifiers, to name a few.

General Properties - ASHACEL^® ethylcellulose polymers are colorless, odorless, tasteless, and noncaloric.  They have outstanding chemical and physical properties. These properties make them useful in many applications - from pharmaceutical, food, and personal care applications to specialty applications, including some of the most sophisticated electronic devices.

Flammability - Once ignited, ASHACEL^® will support combustion. However, ASHACEL^® offers no greater fire hazard on storage and handling than does paper or cellulose in the same physical form.

Thermal Stability - ASHACEL^® is stable up to its melting point (~160°C, 320°F). The viscosity of ASHACEL^® polymers is stable to high temperatures. It has good outdoor durability and toughness at both high and low temperatures.

Low Ash Content - ASHACEL^® has a very low ash content, making it useful in applications such as conductive inks and pastes, dielectrics, ceramics, and fluorescent lighting.

Stability to Light - ASHACEL^® does not discolor on exposure to strong sunlight nor does it promote the discoloration of plasticizers or polymers.

Chemical Stability/Resistance - ASHACEL^® is a stable, slightly hygroscopic material. It is inert to attack by aqueous alkalies, even when hot and highly concentrated. It is resistant to salt solutions and resists oxidation below its softening temperature.

Thermoplasticity - ASHACEL^® possesses excellent thermoplasticity.  Unplasticized ASHACEL^® softens and becomes plastic at 135°C to 160°C Softening point and metling point temperatures .  It can be compounded with plasticizer, waxes, and polymers while in a plastic condition.  Plasticized ASHACEL^® softens at much lower temperatures than unplasticized ASHACEL^® and forms the basis of compositions for molding, extruding, and laminating uses.

Flexibility - Films made from ASHACEL^® polymers are highly flexible and retain their flexibility at temperatures well below freezing.

Film Formation - ASHACEL^® is an excellent film former. Films made from ASHACEL^® are tough, with high tensile strength and an unusual degree of flexibility even at low temperatures. ASHACEL^® polymers yield a greater volume of film-forming solids than any other cellulose derivative.

Compatibility - ASHACEL^® is compatible with most common plasticizers and polymers. It yields clear films with a wider variety of plasticizers and polymers than any other cellulose derivative.

Water Resistance - ASHACEL^® is an excellent water barrier. Films of ASHACEL^® absorb little moisture either on exposure to the atmosphere or after long immersion in water.

Binding - The good binding qualities of ASHACEL^® are useful in applications such as tableting and microencapsulation.

Controlled Release - ASHACEL^® allows control of the release of active ingredients from solid dosage forms.

Solubility - ASHACEL^® dissolves in a wide range of solvents such as aliphatic alcohols, chlorinated solvents, and natural oils. It is practically insoluble in glycerin, propylene glycol, and water.

ASHACEL® ethylcellulose polymers are colorless, odorless, tasteless, and noncaloric. They have outstanding chemical and physical properties. These properties make them useful in many applications - from pharmaceutical, food, and personal care applications to specialty applications, including some of the most sophisticated electronic devices.

Physical Properties a of ASHACEL® Standard cellulose ethers

The bulk density of ASHACELTM Ethylcellulose is approximately 0.3 - 0.4 g/cc.

The product description can be found on both the sales specification and Material Safety Data Sheet (MSDS). 

Depending on grade, the sales specification may show the Material Description as:
Color: white/off-white to tan powder
Odor : none                        

Specific tests to identify ASHACEL^® ethylcellulose are given in the United States National Formulary (NF).

Effective at low percentages of total formulation weight, cast ASHACEL^® ASHACEL Pharma Grade cellulose ethers yield strong films. Film properties depend on the specific ASHACEL^® polymer chosen, on the solvent or solvent blend used for processing, and on the type and amount of plasticizer.

Effect of polymer choice -- The higher viscosity ASHACEL^® polymers tend to yield stronger, tougher films than lower viscosity products. The figure below puts these into perspective for films derived from a complete range of ASHACEL^® products in their respective reference of toluene/alcohol solvent blends.

Load-Elongation Curves for ASHACEL^® Ethylcellulose

“Effect of solvent -- The table below, by contrast, compares viscosity and film properties for a single product, ASHACEL^®MP-10 ASHACEL Pharma Grade polymer, as derived from several solvents which could be used in pharmaceutical processing.”

Viscosity and Film Properties of Unplasticized ASHACEL^® MP 10
in Solvent Blends at 25 C (20 g Resin in 100 ml Solvent)

ASHACEL^® Pharma Grade polymers are soluble in a very wide variety of organic solvents, beginning with aliphatic alcohols such as ethanol and isopropanol. They are compatible with most other familiar organic solvent chemistries, including ether alcohols, ketones, aromatic hydrocarbons, and many more. 

ASHACEL^® products are compatible with most of the common plasticizers. Plasticizers exert greater softening action on ASHACEL^® polymers than on most other cellulose derivatives. The Medium ethoxyl type requires greater concentrations of plasticizers to produce a given degree of softness than does the Standard ethoxyl type. The table below lists plasticizers with high and low softening effect.

Plasticizers with varying softening effects on ASHACEL^® cellulose ethers

In many formulations using ASHACEL^® polymers, 10 to 30% of plasticizer (based on the total solids) is sufficient to produce satisfactory flexibility. The choice of plasticizer depends on the other components and the temperature range or other application or use conditions, rather than on the particular ASHACEL^® polymer. The most widely used plasticizers include phthalates, phosphates, glycerides, and esters of higher fatty acids and amides. For use in compositions that are resistant to low temperatures, long-chain, ester-type plasticizers are recommended. Examples include dibutyl sebacate, butyl stearate, glycol esters of coconut oil fatty acids, and butyl ricinoleate.

Plasticizers used with ASHACEL^® polymers in pharmaceutical applications include dibutyl sebacate, triethyl citrate, triacetin, and acetylated monoglycerides.

Polymers of greater molecular weight yield more viscous solutions. The corresponding films formed are generally tougher and possess higher yield strengths than those created from lower molecular weight materials.  Film permeability can also be adjusted by varying the nominal viscosity of the polymer used, often in conjunction with adjustment of film thickness and plasticizer level.

When you specify an ASHACEL^® cellulose ether product, you get that performance from fast-curing films that won't bottleneck production rates. Consider coatings or matrices of ASHACEL^® ethylcellulose when you need a water vapor barrier to improve product shelf life or prevent hydrolysis of ingredients. Where taste masking is needed, thin films of ASHACEL^® polymers often provide excellent barrier properties.

There is limited compatibility with urea formaldehydes, alkyds of medium oil length, vinyl butyral polymers, and vinyl acetate polymers. Small percentages of ASHACEL^® polymers can be added to these polymers, or small percentages of these polymers can be added to ASHACEL^® products, usually without causing incompatibility or haze. Approximately equal ratios of such polymers and ASHACEL^® polymer will, however, invariably produce hazy or incompatible films.

ASHACEL^® polymers are incompatible with most of the short oil alkyds and vinyl chloride-type polymers. On curing, certain urea formaldehyde and melamine formaldehyde polymers react with ASHACEL^® polymers to greatly improve the solvent resistance and softening point of the finished films. Such compositions have been used, for example, as top coats to protect a gellacquered surface that might come in contact with solvents that would attack the ASHACEL^® polymer alone.

Six different ASHACEL^® Pharma Grade ethylcellulose products are available for pharmaceutical applications, as shown in the table below. ASHACEL^® Pharma Grade Polymers for Pharmaceutical Applications

Although certainly not all-inclusive, the table below provides starting point recommendations for various formulating technologies. 

ASHACEL^® ethylcellulose polymers have provided excellent functionality in many pharmaceutical and specialty applications . ASHACEL^® polymers are essentially tasteless, odorless, noncaloric, and physiologically inert. They offer an attractive range of physical properties and can be blended with other materials to achieve intermediate characteristics.

Pharmaceuticals - ASHACEL^® MP products are among a very small number of water-insoluble excipient polymers that are approved and accepted globally for pharmaceutical applications. They are proven organosoluble polymers for tablet coatings, controlled-release coatings, microencapsulation, granulation, and taste masking.

Personal Care - ASHACEL^® polymers are approved for use in cosmetics. Ethylcellulose is listed in the International Cosmetic Ingredient Dictionary and Handbook. It is also listed in the Japanese Standards of Cosmetic Ingredients.

ASHACEL^® is soluble in many organic solvents, including ethanol and natural oils. It yields strong, flexible films at low concentration. It provides excellent water resistance and can be used to protect water-sensitive ingredients. It can be used to mask or control the release of active ingredients.

ASHACEL^® has been used in lipsticks and nail polishes (gives long-lasting brilliance), as a fragrance stabilizer, and as a thickener for perfumes and body creams (waterproof sunscreens).

Food - ASHACEL^® is used as a flavor fixative in encapsulation and as a vitamin coating. It is approved for and used in inks for marking fruits and vegetables, as a component of paper and paperboard in contact with aqueous and fatty foods, and for certain uses in animal feed.

Ceramics - ASHACEL^® is used in ceramic applications as a rheology modifier and binder. It provides green strength to the unfired ceramic and burns out cleanly, leaving no residue after firing.

Conductive Pastes - ASHACEL^® is used in conductive pastes and inks. It functions as a rheology modifier and as a binder and stabilizer for metal pigments. It burns out cleanly, leaving no residue after firing.

Printing Inks - ASHACEL^® is used in gravure, flexographic, and screen printing inks. It is soluble in common solvent systems and is compatible with plasticizers, waxes, and other polymers commonly used. It functions as a rheology modifier, dispersant, and binder for pigments and as a polymeric binder for pigment chips. It contributes to the formation of tough, abrasion-resistant films. It reduces tack of ink films and improves printability on difficult substrates. Ink films dry quickly because of the permeability of films of ASHACEL^® polymers.

Specialty Coatings - ASHACEL^® brings an unusual combination of properties to specialty coatings applications.

Hot Melts - ASHACEL^® dissolves readily in many hot polymers, plasticizers, and oil and wax mixtures. It has excellent thermoplasticity.

Adhesives - Hot melts using ASHACEL^® can be easily heat-sealed. ASHACEL^® contributes added strength especially where stresses may be applied to a freshly sealed joint.

Paper Coatings - ASHACEL^® provides remarkable toughness (resistance to scuffing) and flexibility at room temperature and low temperatures. The coating has good gloss and block resistance and retains a low rate of water vapor transmission.

Fluorescent Lighting - ASHACEL^® acts as a rheology modifier and binder for coating fluorescent lighting tubes. ASHACEL^® is removed by heating. It burns cleanly, leaving no residues, which allows the triphosphor coating to adhere to the glass tube.

Other Applications - ASHACEL^® is also used in waterproofing coatings, high temperature/maintenance coatings, enameling, lacquers, varnishes, and marine coatings.

ASHACEL^® polymers have a long history in film and bead coating for controlled release applications. ASHACEL^® forms a strong film with good adhesion. These polymers can provide a versatile diffusion barrier whose properties can be modified by film thickness, the level of pore-forming additives, or by modifying the solvent(s) used and molecular weight of ASHACEL^®.

ASHACEL^® polymers can be applied with conventional coating techniques such as pan and fluidized bed coating.

When you need one or more of the advantageous characteristics of multiparticulate systems, ASHACEL^® polymers offer excellent routes to controlling drug release.
 
As water insoluble excipients, ASHACEL^® polymers can effectively control the release of an active by modifying the size and length of the diffusion path. In this role, an ASHACEL^® polymer is typically used in combination with a water-soluble active and/or water-soluble excipient such as a Hydroxypropyl methyl cellulose. By varying the type and amount of insoluble/soluble excipient ratio and the particle size, a wide variety of release rate profiles can be achieved. Micro-encapsulated particles of ASHACEL^® can also use these techniques.

ASHACEL^® polymers are used as tablet binders in roller compaction granulation or direct compression tableting. In these applications they produce hard tablets with very low friability. When used in small but effective amounts, ASHACEL^® ethylcellulose will not adversely affect tablet disintegration or dissolution rates.

ASHACEL^® polymers are commonly used to micro-encapsulate pharmaceutical actives for sustained release or taste masking applications. This can be accomplished by coacervation or fluidized bed coating techniques. The coated particles of ASHACEL^® provide a tough controlled release film which can be compressed directly into tablets.

ASHACEL^® polymers are approved for use in cosmetics. Ethylcellulose is listed in the International Cosmetic Ingredient Dictionary and Handbook (INCI). The INCI name for ASHACEL^® is ethylcellulose. It is also listed in the Japanese Standards of Cosmetic Ingredients.

ASHACEL^® ethylcellulose polymers are naturally derived polymeric materials. ASHACEL^® is not a skin sensitizer, it is not irritating to the skin, it is not mutagenic.

ASHACEL^® is soluble in many organic solvents, including ethanol and natural oils. It yields strong, flexible films at low concentration. It provides excellent water resistance and can be used to protect water-sensitive ingredients.

ASHACEL^® has been used in lipsticks and nail polishes (it gives long-lasting brilliance), as a fragrance stabilizer, and as a thickener for perfumes and body creams (waterproof sunscreens). It can be used to mask or control the release of active ingredients.

ASHACEL^® FP polymers may broaden formulation options available in the area of personal care. ASHACEL^® polymers have been used for decades in the hydrated state as water-resistant film formers in sunscreens, lipsticks, and ointments. The enhanced lipophilic and hydrophobic properties of ASHACEL^® FP in the unhydrated state can be used to improve controlled release of oily actives, improve stability of an active, and in viscosity modification. 

Since ASHACEL^® polymers are not water soluble, typically cleaning is done using a suitable solvent for dissolution of the polymer and compatibility with your environment.   Here is a solubility table that may be helpful.  Also, refer to the Material Safety Data Sheet for safe handling procedures.  ASHACEL^® resins can be difficult to clean.  A solvent system used in the Dow labs for preparing solutions for testing is 60/40 toluene/ethanol.  This may be used for cleaning.  If a toluene blend is not acceptable in your application, ethanol alone may work.

Safe handling of Ashacel ethylcellulose

Material Safety Data Sheet on Ashacel ethylcellulose polymers should be obtained from us PRIOR TO handling or using the product.

The materials along with Ashacel, particularly solvents may constitute separate toxicity or fire hazard. Please ensure to get Material Safety Data Sheets for each of the product from respective suppliers prior to using them with Ashacel.

Health considerations:

Ashacel ethylcellulose products are thermoplastic polymers with a cellulose backbone. Dust from Ashacel products could conceivably cause temporary mechanical irritation to the eye under extreme conditions. When inhaled, it is considered as nuisance dust. However, the products are considered to present no significant or unusual health hazard to personnel in normal industrial handling. Hence, no special precautions need to be observed to handle the products safely other than the possible need for a local exhaust system to control dust during opening and dumping the fibre drums.

Combustibility:

Dust of Ashacel ethylcellulose in air can reach explosive levels and care must be taken to prevent this.

Ashacel products are of organic origin and will burn under the right conditions of heat and oxygen levels. Ashacel products will melt upon exposure to an open flame. Once melted and ignited, these products will support combustion. Any available extinguishing agent can extinguish such fires.

Spills:

To prevent accidents, good house keeping requires that spills should be thoroughly vacuumed or swept. Any slight residual product on the walls or floor can then be flushed with water into a sewer. For small spills of liquid formulations of Ashacel products, a solid adsorbent should be used to absorb the liquid. Any solvents should then be allowed to evaporate and the absorbate containing Ashacel product should be disposed of through approved landfill or incinerations.

For large liquid spills, appropriate diking precautions should be taken until the solution can be collected for proper disposal. In liquid solution spills, solvents may present significant health and fire risk.

Disposal:

ASHACEL^® polymers are water insoluble and do not biodegrade in aqueous environment. Hence, there is no ecological hazard presented by these polymers.

ASHACEL^® products can be disposed of by burning in an incinerator or by burial in approved landfill. Incineration should be done under carefully controlled conditions to avoid dust explosion.

If the formulation containing Ashacel polymers needs to be disposed, it is recommended to consult disposal other formulation ingredients as well before deciding upon the disposal method.

In disposal of any wastes be certain to meet all the regulatory requirements.

Storage:

Ashacel products should be stored at ambient temperatures not exceeding 35ºC in a dry area away from all sources of heat.

In storage or use, good house keeping practices need to be followed to prevent dust or fine powder of Ashacel reaching explosive levels in air.

Ashacel products should not be stored in vicinity of peroxides or other oxidizing agents.

Ashacel products should be stored following current Good Manufacturing Practices requirements. These products should not be stored near hazardous or non-food chemicals.

Please refer the present MSDS.

ASHACEL® ethylcellulose products, do not contain material that has been irradiated nor have they been manufactured at any stage with irradiation.

The ASHACEL^® products are stored in a large, indoor warehouse at ambient temperatures in Valsad, Gujrat, India. The temperature and humidity of the warehouse is generally not controlled except during colder weather where an internal heating system may be used to ensure tolerable working conditions for warehouse personnel.

The ASHACEL^® ethylcellulose sales specification for ASHACEL Pharma Grade grade products identify both the Total Aerobic Microbial Count and Total Combined Yeast & Mold Count with a max allowable limit of 100 CFU/g.  The limit of detection due to the dilution factor is <10 CFU/g for these tests. 

When preparing (Material) Safety Data Sheets Asha draws from the best available information generated within Asha and gathered from external sources. A significant amount of work has been completed on cellulosic polymers available in the open literature.

Listed below are two references on toxicological work done on cellulosics.

• JECFA (1990) WHO Food Additives Series: 26. "Toxicological evaluation of certain food additives and contaminants"
• Opdyke, Food Cosmet Tox 19, 113, 1981

Yes, both ASHACEL Pharma Grade and Industrial grade ASHACEL^® polymers are manufactured in compliance with the cGMP requirements for indirect food additives and comply with US FDA Indirect Food Additive regulations (21 CFR Parts 174 - 179, 181, 186).

As suggested by the Inactive Ingredient Guide (published by the Division of Drug Information Resources, the Food and Drug Administration, July 2004), the highest level of ethylcellulose in a drug form currently being used is approximately as shown in the following table:

As suggested by the Inactive Ingredient Guide (published by the Division of Drug Information Resources, the Food and Drug Administration, July 2004), the highest level of ethylcellulose in a drug form currently being used is approximately as shown in the following table:

The toxicology studies on our ASHACEL^®  ethylcellulose products indicate a very low order of acute toxicity in animal studies by the peroral or percutaneous routes of exposure.  These polymers are not absorbed from the gastrointestinal tract, but appear to be completely and rapidly eliminated.

Long-term feeding studies in the rat have established a no-observable effect level (NOEL) of 1.2% ethylcellulose in the diet.  Extrapolating the NOEL for rats to humans, and allowing for a 100-fold safety factor, yields an acceptable level of intake that suggests that the upper limit of the amount of ASHACEL^® ethylcellulose in a tablet could be reasonably set higher than the amount indicated above.  

Please note that this estimate is for single-tablet daily dosage forms in adults. Other dosages in other target populations may warrant a refinement of this estimate.

ASHACEL^® Pharma Grade ethylcellulose complies with the compendial specifications of the National Formulary (XVIII), (Ethylcellulose) the Food Chemicals Codex (Ethylcellulose). They also meet the requirements of the Japanese Standards of Pharmaceutical Ingredients (JSPI), and meets the requirements of the European Pharmacopeia (EP). ASHACEL^® Pharma Grade ethylcellulose polymers meet the requirements of the FDA food regulations outlined in the table below. FDA Compliance of ASHACEL^® Pharma Grade Ethylcellulose Polymers