This group of polymers are widely used for enteric coating applications as they contain free carboxylic acid groups that are ionized whenever the pH of the environment exceeds 5. They are produced by an emulsion-polymerization process and were first introduced for enteric coating applications by Lehmann and Dreher in the mids.
Several different types of Eudragit polymers with enteric release capabilities are commercially available in a wide range of different physical forms aqueous dispersion, organic solution, granules and powders.
The pH at which these polymers dissolve is dependent on the content of the carboxylic acid in the copolymer. Methacrylic acid methylmethacrylate copolymers Eudragit L and S , and methacrylic acid ethyl acrylate copolymer Eudragit L30D are the preferred choice of coating polymers for enteric formulations. They allow targeting of specific areas of the intestine. Eudragit polymers used in enteric coating and their dissolution pH. Read Also: Examples of film-coated tablets.
Enteric-coated tablets are compressed tablets coated with substances that do not dissolve in the acidic condition of the stomach but readily dissolves in the alkaline pH of the small intestine. Most enteric coatings work by presenting a surface that is stable to highly acidic pH of the stomach but breaks down rapidly at a less acidic relatively more basic pH. Enteric-coated tablets should never be cut or crushed. Related keywords: enteric coating process, enteric coated tablets slideshare, disadvantages of enteric coated tablets, list of enteric-coated tablets, enteric coating defects, is enteric coating safe, enteric coated tablets pdf, enteric coating side effects.
Formulation, Manufacture and Evaluation of Chewable tablets. February 22, January 3, December 17, November 13, Your email address will not be published. Share on Facebook Share on Twitter. Contents 1 Reasons for the application of enteric coatings 2 Ideal properties of enteric coating materials 3 Polymers used for enteric release film coating 3.
Cellulose acetate phthalate CAP 3. Cellulose acetate trimellitate CAT 3. Polyvinyl acetate phthalate PVAP 3. With an enteric coating, the medication releases depending on the pH value within the GI tract that initiates breakdown of the specific finish applied. The strategy of using pH as a trigger to achieve specific release of a product arises from the learning of pH variation along the GI tract.
Progressing through the GI tract, the pH values change substantially and specifically. While the exact pH within areas of the body can vary slightly from time to time and from person to person, refer to the adjacent diagram for a general range of typical values within the human digestive tract.
Natural products such as fish oil and peppermint oil are of benefit to the consumer when an enteric coating allows release in the intestine but, when consumed uncoated, these products would release in the stomach, possibly decreasing efficacy and causing unwanted effects on the upper GI tract.
Some medication compounds can contain a casing layer that releases active ingredients immediately in the stomach, with an inner enteric coating, which delays release of the inner core, usually a different medication, until farther down the GI tract.
Shellac is an example of a natural polymer used as an enteric coating. Derived from the resinous secretions of the Kerria lacca insect, as it goes through the pupa stage, this substance is water insoluble at low pH acid and water-soluble at higher pH alkaline.
Farmers even apply it to apples and other fruit to preserve them through the food supply chain. They require specific coatings to reach precise affected locations in the GI tract for direct application to the intestinal mucosa.
Otherwise, they are absorbed by the body overall, potentially resulting in an increased incidence of adverse drug reactions. It is a pressed tablet containing a mixture of drug microspheres, which are coated with one, two, or three layers of ethylcellulose. After passing safely through the stomach, the one-layer granules release in the upper small intestine, the two-layer granules release later in the small intestine, and the triple-covered granules in the colon.
Its precise release at a pH of 7. Complete dose delivery to the disease area is critical. Patients with moderately active ulcerative colitis treated with 4. This knowledge is important in choosing medications, particularly in instances when considering a generic version for treatment. Develop and improve products.
List of Partners vendors. When deciding on a drug, it is important to weigh the risks against the benefits. Commonly used back pain medications such as NSAIDs have known side effects that can result in serious stomach problems. Enteric-coated medication may potentially help avoid this problem. The American College of Gastroenterology says the use of NSAIDs for pain relief, musculoskeletal disorders, and arthritis , while valuable, has been limited based on an association this class of medication has with ulcers and other upper GI tract injuries.
One way the pharmaceutical industry addresses this potential complication is by coating the pills. Enteric-coated pain medication is surrounded by special ingredients that are said to prevent irritation of the stomach lining and usually come in tablet or capsule form. Enteric-coated drugs do their work by keeping the drug's active ingredient from releasing until it has gone all the way through the stomach and arrives in the small intestine.
The word enteric means "relating to the intestine. Cutting, crushing, or breaking an enteric-coated medication before taking it negates its protective effect and exposes the stomach to potential irritation.
Crushing or breaking an enteric-coated medication may lead to serious side effects, may prevent the medication from working properly, and may slow down your recovery rate. Always read the patient information leaflet or check with your pharmacist to see if it is safe to crush your tablets or open your capsules. If your needs have changed and you are finding it difficult to swallow tablets or capsules, then contact your physician, who will prescribe your medication in another form that is easier for you to take.
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