Benefits of Enteric Coated Tablets

Enteric Coated

Enteric coated tablets are solid unit dosage forms which are designed to bypass the stomach and release the drug in small intestine and are meant for oral administration. The word “enteric” indicates small intestine; therefore enteric coatings prevent release of medication before it reaches the small intestine. Most enteric coatings work by presenting a coated surface that is stable at the highly acidic pH found in the stomach, but breaks down rapidly at a less acidic (relatively more basic) pH. Materials used for enteric coatings include CAP, CAT, PVAP and HPMCP, fatty acids, waxes, shellac, plastics and plant fibers. The present review describes enteric coating, their ideal properties, benefits and limitation, various polymers used, their chemical structure, criteria for drug selection and mechanism, methods of manufacturing and evaluation of enteric coated tablets. Recently, these have attracted the interest of many formulators due to their advantages over the conventional drug delivery systems as they prolong the dosing intervals and also increase patient compliance. The study provides an overview of the recent advances that have taken place in this arena.

Tablet coating 

Coating is a process by which an essentially dry, outer layer of coating material is applied to the surface of a dosage form in order to confer specific benefits that broadly ranges from facilitating product identification to modifying drug release from the dosage form. After making a good tablet, one must often coat it. Coating may be applied to multiple range of oral solid dosage form, including tablets, capsules, multiparticulates and drug crystals. When coating composition is applied to a batch of tablets in a coating pan, the tablet surfaces become covered with a tacky polymeric film. Before the tablet surface dries, the applied coating changes from a sticky liquid to tacky semisolid and eventually to a non-sticky dry surface pans. The entire coating process is conducted in a series of mechanically operated acorn-shaped coating pans of galvanized iron stainless steel or copper. The smaller pans are used for experimental, developmental, and pilot plant operations, the larger pans for industrial production.

Coating Process Design & Control

In most coating methods, when the tablets are being agitated in a pan, fluid bed, etc. at that time spraying on tablets by coating solution takes place. As the solution is being sprayed, a thin film is formed that adheres directly to each tablet. The coating may either be formed by a single application or may be built up in layers through the use of multiple spraying cycles. In pharmaceutical industry, rotating coating pans are often used. Firstly, uncoated tablets are placed in the pan, which is typically tilted at an angle from the horizontal, and then the liquid coating solution is introduced into the pan while the tablets are tumbling. By passing air over the surface of the tumbling tablets, the liquid portion of the coating solution is then evaporated. In comparison, a fluid bed coater operates by passing air through a bed of tablets at a velocity sufficient to support and separate the tablets as individual units. Once separation takes place, then the tablets are sprayed with the coating composition. 

The coating process is usually a batch operating task consisting of the following phases:

• Identification of batch and Recipe selection (film or sugar coating)
• Loading/Dispensing (accurate dosing of all required raw materials)
• Warming
• Spraying (Both application and rolling are carried out simultaneously)
• Drying
• Cooling
• Unloading

Coating equipment A modern tablet coating system combines several components:

• A coating pan
• A spraying system
• An air handling unit
• A dust collector

Advantages of tablet coating

• Tablet coatings must not make tablets stick together during the coating process, must follow the fine contours of embossed characters or logos on tablets and must be stable and strong enough to survive the handling of the tablet.
• Printing on tablets can also be done by coatings, if required. Coatings are necessary for tablets giving a smoother finish, makes large tablets easier to swallow and also to mask the unpleasant taste.

Benefits of Enteric Coated Tablets

Related for Nursing Implications and Drugs Guide Information

1. Nursing Implications for Vecuronium Bromide
2. Nursing Implications for Venlafaxine (ven-la-fax′een)
3. Nursing Implications for Verapamil Hydrochloride
4. Nursing Implications for Vilazodone Viibryd
5. Nursing Implications for Vinblastine Sulfate
6. Nursing Implications for Vincristine Sulfate Vincasar PFS
7. Nursing Implications for Vinorelbine Tartrate Navelbine

Disadvantages of tablet coating

• Limitations of sugar coating such as relatively high cost, long coating time and high bulk have led to the use of other coating materials.
• However the process of coating is tedious and time-consuming and it requires the expertise of highly skilled technician.

There are four reasons for putting such a coating on a tablet or capsule ingredient:

• Protection of active pharmaceutical ingredients, from the acidic environment of the stomach (e.g. enzymes and certain antibiotics).
• To prevent gastric distress or nausea from a drug due to irritation (e.g. sodium salicylate).
• For the delivery of drugs that are optimally absorbed in the small intestine to their primary absorption site in their most concentrated form.
• To provide a delayed-release component for repeat action.
• Required for minimizing first pass metabolism of drugs.

The choice of the polymer and the thickness of the coated layer are critical to control the pH solubility profile of the enteric coated dosage form. The most common drugs which cause stomach ulcers like aspirin, diclofenac and naproxen are frequently available with enteric coatings. Omeprazole, which is a drug which stops the stomach from producing acid, is itself broken down in acid and therefore the drug generally has an enteric coating around it either as a granule in the capsules or as a granule in the dispersible form. Sulfasalazine is used either for the treatment of Crohn's disease which is inflammation of the intestines or for the treatment of arthritis. When used for Crohn's disease where it is needed in the intestines to work, it is given with an enteric coating whereas for arthritis it is very often given without an enteric coating so that it can be absorbed more quickly.

ERY-TAB is an antibacterial product containing erythromycin base in an especially enteric-coated tablet to protect it from the inactivating effects of gastric acidity and to permit efficient absorption of the antibiotic in the small intestine. ERY-TAB (erythromycin delayed-release tablets) are available for oral administration in three dosage strengths, each white oval tablet containing 250 mg, 333 mg, or 500 mg of erythromycin as the free base. Other commercially available tablets are enteric coated aspirin. E.g. Micropirin® 75mg EC tablets and enteric coated peppermint oil. E.g. Colpermin®

ETP tablets are composed of three layers, a drug containing core tablet (rapid release function), the press coated swellable hydrophobic polymer layer (Hydroxy propyl cellulose layer (HPC), time release function) and an enteric coating layer (acid resistance function).[12,13] The tablet does not release the drug in the stomach due to the acid resistance of the outer enteric coating layer. The enteric coating layer rapidly dissolves after gastric emptying and the intestinal fluid begins to slowly erode the press coated polymer (HPC) layer. Rapid drug release occurs when the erosion front reaches the core tablet since the erosion process takes a long time as there is no drug release period (lag phase) after gastric emptying.

Benefits of Enteric Coating

• Protects capsule or tablet contents from acidic environments of stomach
• After passing through the stomach allows capsule or tablet to break down easily in pancreatic juices in the Duodenum (approximately 1st10” of small intestine) (pH 6‐8)
• Enables absorption of enzymes, at their highest activity levels, in the small intestine

Proof that Enteric Coating Works

Conducted “Disintegration Tests (Enteric Coated Capsules)” following procedures from Japanese Pharmacopeia (General Tests, 15thEdition)

Two Test Conditions

1. First test simulates gastric fluid (harsh stomach conditions): pH 1.2for 120minutes at 37°C (98.6°F)
2. Second test simulates intestinal fluid (duodenum): pH 6.8for 60minutes at 37°C (98.6°F)

Test Results for Enteric Coated Capsules

1. Stomach Conditions –Capsules did not disintegrate
2. Intestinal (duodenum) Conditions –Capsules disintegrated completely

Enteric Coating State of the Art

• Revolutionary process for Enzymes; similar to enteric coating process used in today’s most advanced products.
• All natural shell that withstands pH levels found in Stomach.
• Designed to pass USP (United States Pharmacopeia) and JP (Japanese Pharmacopeia) disintegration tests.
• Every batch is tested to ensure it meets agency guidelines before export to U.S.

Benefits of Enteric Coating:Summary

• Uncoated Capsules and Tablets lose the effectiveness of their enzymes when passing through the stomach (Enzymes are destroyed)
• Enteric Coating protects a capsule’s contents in the highly acidic environments of the Stomach
• Enteric Coating breaks down completely in neutral pH environments of the Duodenum
• Enteric Coating enables delivery of enzymes for absorption with maximum activity levels intact into the Small Intestine

References

http://spiritofmaat.com/maatshop/Vitalzym_Enteric_Coating_info.pdf

http://www.iosrphr.org/papers/v2i6/Part_1/B0260511.pdf

Tweet

Jangan sampai ketinggalan postingan-postingan terbaik dari Nursing Implications for Drugs. Berlangganan melalui email sekarang juga:

Atau sobat juga bisa follow Nursing Implications for Drugs dengan mengklik tombol di bawah ini:

Artikel keren lainnya:

Ditulis oleh Unknown pada tanggal Monday, July 27, 2015