Oral drug administration enteric coatings

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

It should be emphasized that the formulation plays an important role in the effect of these glycerides (emulsification, enteric coating, etc.) The main advantage of these products is their general acceptance for use in oral drug administration. " ... 

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. 

The protection of a drug substance from the destructive influence of gastric acid after oral administration (such as enteric-coated tablets)... 

Drugs are administrated by intravenous routes or ex-travascular routes including oral, sublingual, subcutaneous, intramuscular, rectal (by enema or suppository), and transdermal. Available dosage forms include suspensions, immediate-release capsules or tablets, sustained-release capsules or tablets, and enteric-coated capsules or tablets that resist dissolution in the acidic pfi of the stomach. 

The use of enteric coatings will increase as the availability of protein drugs increases and these agents become less expensive. The interest in the oral administration of these proteins will increase despite the lingering problem of very low bioavailability (e.g., insulin). 

Pantoprazole is sensitive to degradation in the acidic medium of the stomach, so the drug is formulated in enteric-coated formulations. Pantoprazole is rapidly absorbed after oral administration, with peak plasma concentrations (Cmax) of 1.1 to 3.1 (mean 2.1 mg/L) occurring at 2 to 4 (mean 2.7) hours (tmax) after ingestion of an enteric coated 40 mg tablet. 

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... 

Bisacodyl is a laxative that is indicated in short-term treatment of constipation evacuation of colon for rectal and bowel evaluation preparation for delivery or surgery. Bisacodyl is the only diphenyhnethane derivative available in the United States. It is marketed as an enteric-coated preparation (Dulcolax, Correctol, others) and as a suppository for rectal administration. The usual oral daily dose of bisacodyl is 10 to 15 mg for adults and 5 to 10 mg for children 6 to 12 years old. The drug requires hydrolysis by endogenous esterases in the bowel for activation, and so the laxative effects after an oral dose usually are not produced in less than 6 hours taken at bedtime, it will produce its effect the next morning. Suppositories work much more rapidly. 

Intramuscular administration of nitrofurantoin sodium may also be successful in metastatic seminoma, the drug apparently decreases the size of lung metastases thus improving the patient s condition . Owing to the low blood levels which are achieved with nitrofurantoin, all indications for its use aside from urinary tract infections have meanwhile been abandoned hence nitrofurantoin is used orally as well as parenterally for the treatment of urinary tract infections only. Intravenous use of nitrofurantoin does not produce higher urine levels than oral administration or intramuscular injection does . A comparison of all three modes of application has proved that orally-administered nitrofurantoin is absorbed completely and metabolized rapidly since maximum drug levels appear in the urine within thirty to sixty minutes after administration. To reduce the rate of side effects, enteric coated tablets may be administered. Numerous reports especially from Japan have led to the conclusion that such tablets are absorbed at a slower rate and are, therefore, probably better tolerated. On the other hand, it seems likely that adequate bacteriostatic levels cannot be achieved and hence a higher failure rate will ensue with this method. 

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