Enteric coating disintegration

Oral administration of bicarbonate may decrease the absorption of ketoconazole. Increased blood levels of quinidine, flecainide, or sympatiiomimetics may occur when these agents are administered with bicarbonate There is an increased risk of crystalluria when bicarbonate is administered with the fluoroquinolones. Fbssible decreased effects of lithium, methotrexate, chlorpropamide, salicylates, and tetracyclines may occur when these drag s are administered with sodium bicarbonate. Sodium bicarbonate is not administered within 2 hours of enteric-coated drugs the protective enteric coating may disintegrate before the drug reaches the intestine. 

A drug should always be ingested with a cup of water ( 8 oz) to insure easy transit down the esophagus and to provide fluid for disintegration and dissolution. Whether or not the drug should be taken on an empty stomach (e.g., enteric-coated tablets) or with food will depend upon the specific drug as noted above. 

Garlic supplements - powder tablets or capsules, steam-distilled oil, vegetable oil macerate extract, or extract aged in dilute alcohol - are widely available and are taken by millions. Since the active principle, allicin, is not present in garlic bulb, the supplements rely on the presence of precursor alliin and enzyme alliinase. In tests on 24 commercial brands of enteric-coated tablets, all except one gave low dissolution allicin release 83% of the brands released less than 15% of their potential allicin.78,79 Relevant factors were impaired enzyme activity caused by excipients and slow tablet disintegration. Caveat emptor ... 

T. Beckert, K. Lehmann, P. C. Schmidt, Compression of enteric-coated pellets to disintegrating tablets, Int J Pharm 743 13-23 (1996). 

Disintegrate in stomach after taken orally Enteric coated tablets to keep tablets intact in stomach and disintegrate in intestines for absorption Release drug slowly for a period of time to reduce administration times... 

Strieker H, Kulke H. Rate of disintegration and passage of enteric-coated tablets in gastrointestinal tract [in German]. Pharm Ind 1981 43 1018-1021. 

Studies using the USP disintegration test for enteric-coated tablets have indicated that there is a marked increase in the disintegration time over a 6-month storage period for shellac-coated tablets. " It is likely that this effect is due to the polymerization of shellac, which occurs over storage periods of this duration. A specification for shellac is contained in the Food Chemicals Codex (FCC). 

Luce GT. Disintegration of tablets enteric coated with CAP. Manuf Chem Aerosol News 1978 49(7) 50, 52, 67. 

Figure 21.4 Velocity profile of an enteric-coated tablet from ingestion until disintegration in the small intestine (gastric emptying at 24 min).

Morrison A, Campbell J. The relationship between physiological availability of salicylates and riboflavin and in vitro disintegration time of enteric coated tablets. J Am Pharm Assoc 1960 49 473 78. 

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