Enteric-coated dosage form

Which of the following is unlikely to be associated with oral drug administration of an enteric-coated dosage form ... 

For some products, e.g., propanolol extended release formulations (USP 27), a modification of the standard method for enteric-coated dosage forms have been introduced to reflect the change from conditions in the stomach to those in the small intestine. This is a step in the right direction, but to achieve dissolution testing that can differentiate between formulations which are robust and those which are not, and especially to be able to predict food effects on the release from... 

Figure 11 Titer of anti-short ragweed IgG antibodies, treated and placebo. The amount of IgG was increased by administration of the enteric-coated dosage form. Without enteric film coating the antibodies would have been destroyed. (Source Ref. 68.)...

Numerous strategies have been developed to achieve colon-specific drag delivery. Some approaches, such as the use of sustained release formulations, enteric-coated dosage forms and osmotic pumps, were not... 

The limitations of enteric-coated dosage forms include the possibility of duodenal irritation from caustic drugs and an increase in intersubject variability... 

Most patients with malabsorption will require pancreatic enzyme supplementation and a reduction in dietary fat in order to achieve satisfactory nutritional status and become relatively asymptomatic. An initial prandial dose of 30,000 international units of lipase (uncoated tablet, capsule, or powder) is recommended to be given with each meal (see Fig. 34—5). Alternatively, the use of microencapsulated enteric-coated dosage forms may be used. The total daily lipase dose should be titrated to reduce steatorrhea. In some patients a reduction in dietary fat may be necessary. The addition of an antisecretory drug should be reserved for patients resistant to enzyme therapy (see Fig. 39-5). If these measures are ineffective, documentation of the diagnosis and exclusion of other diseases should be undertaken. 

In some cases, medications that cost more may be more cost effective. This is particularly true with pancreatic enzymes and the microencapsulated enteric-coated dosage forms. These latter products may cost more per unit, but they offer greater patient acceptance and compliance when compared to uncoated tablets. In addition, when cost is based on the total number of tablets or capsules per day, rather than the cost of a single tablet or capsule, the high-potency preparations are usually similar in price to the uncoated products. The addition of an H2-receptor antagonist or proton pump inhibitor may actually be cost effective for patients who are not adequately controlled on maximal enzyme therapy. 

Usually salt formation is carried out to increase the solubility of the base, however, salts with lower solubilities are sometimes prepared to, e.g., mask taste, provide slower dissolution and increase chemical stability. An example of salt formation to decrease dissolution rate is described by Benjamin and Lin (1985), who prepared a range of salts of an experimental antihypertensive as shown in Table 3.10. The solubilities and intrinsic dissolution rates (IDR) of the prepared salts of this compound are also shown in Table 3.10. These in vitro tests showed that there were significant differences in the dissolution rate when the experiments were performed in water and buffer. However, the difference in the IDRs of the salts was similar in 0.1 M HC1. Hence, it was recommended that ebonate, 3-hydroxynaphthoate or napsylate salts should be formulated as enteric-coated dosage forms. This would avoid dissolution in the stomach acid, which could cause local GI irritation, and would still provide release of the compound. 

It is considered to be one of the choicest drug specifically for salicylate medieation and is usually administered with either sodium bicarbonate to minimise effeetively the gastric distress or as enteric-coated dosage forms. However, the usage of NaHCOj is not advisable as it is found to retard the plasma levels of salicylate and enhances the elimination of free salicylate in the urine. 

A reservoir system consists of an active substance and a membrane, and therefore is also known as a membrane coti-trolled system. A membrane or coating can be applied to a whole tablet or capsule, or to a tablet core. Granulates and even crystals can be coated as well, which are then processed into tablets or capsules. Enteric-coated dosage forms have an acid-resistant coating, which dissolves when the pH is increased. An osmotic system may be regarded as a particular reservoir system, because it has a semi-permeable membrane that is provided with holes with an exact diameter. 

Gastric emptying of enteric-coated dosage forms... 

Bogentoft C, Carlsson I, Ekenved G, Magnusson A (1978) Influence of food on the absorption of acetylsalicylic acid from enteric-coated dosage forms. Eur J Clin Pharmacol 14 351-355... 

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