Oral administration, tablet, capsule

Ginkgo extracts show rapid absorption after oral administration of capsules, tablets, and drops (Li and Wong 1997 Wojcicki et al. 1995). The pharmacokinetics for the ginkgo terpene lactones have been determined... 

When a drug is administered orally via tablet, capsule, or suspension, the rate of absorption often is controlled by how fast the drug particles dissolve in the fluid at the site of administration. Hence, the dissolution rate often is the rate-limiting (slowest) step in the following sequence ... 

The oral route is the most frequent route of drug administration and rarely causes physical discomfort in patients. Oral drug forms include tablets, capsules, and liquids. Some capsules and tablets contain sustained-release drag s, which dissolve over an extended period of time. Administration of oral dru is relatively easy for patients who are alert and can swallow. 

Fig. 4 Mean cumulative urinary excretion of nitrofurantoin after oral administration of a 100-mg macrocrystalline capsule of fasting (O) and nonfasting ( ) subjects and a 100-mg microcrystalline tablet to fasting ( ) and nonfasting ( ) subjects. Vertical bars represent standard errors of the mean. (From Ref. 7.).

Comparative bioavailability data are discussed where a number of different dosage forms/routes of administration have been used during the development process, e.g., tablets, capsules, oral solutions, granules, and injections. 

Oral (PO = per os) By the mouth. Oral administration is the most common route employed for a variety of dosage forms tablets, capsules, liquids, suspensions. The major site of absorption is the small intestine. Alcohol is absorbed from the stomach. 

Identical doses of a capsule preparation (X) and a tablet preparation (Y) of the same drug were compared on a blood concentration-time plot with respect to peak concentration, time to peak concentration, and AUC after oral administration as shown in the figure below This comparison was made to determine which of the following ... 

Absorption - Following oral administration, peak serum concentrations of digoxin occur at 1 to 3 hours. Absorption of digoxin from the tablets has been demonstrated to be 60% to 80% complete compared with an identical IV dose of digoxin (absolute bioavailability) or capsules (relative bioavailability). 

Nitroglycerin, the prototype of the nitrates is characterized by a rapid onset and short duration of action. It is usually administered sublingually (via the oro-mucosal route), which allows a rapid and efficient absorption and avoids the strong first pass effect after oral administration. Nitroglycerin is available as tablets, capsules (for sublingual administration) but also as transdermal preparations, sprays, and ointments. 

Oral administration is a relatively safe route for sustained action drug delivery. Oral delivery allows the use of either tablets or capsules [1]. A wide range of techniques is available for their preparation. 

Tramadol is available as drops, capsules, and sustained-release formulations for oral use, suppositories for rectal use, and solution for intramuscular, intravenous, and subcutaneous injection. After oral administration, tramadol is rapidly and almost completely absorbed. Sustained-release tablets release the active ingredient over a period of 12 h, reach peak concentrations after 4.9 h, and have a bioavailability of 87 to 95% compared with capsules. One 100-mg dose given to healthy volunteers resulted in plasma levels of 375 ng/ml at 1.5 h.55 Tramadol is 20% bound to plasma protein and it is rapidly distributed in the body it is mainly metabolized by O- and A-demethylation forming glucuronides and sulfates that are excreted by the kidney. 

Etodolac is rapidly absorbed after oral administration. The maximal plasma concentrations (Cmax) of etodolac are achieved within 1 to 2 hours of administration of tablets or capsules in healthy subjects [38]. The time to maximal plasma concentration (W) increases to approximately 8 hours with the sustained release formulation [18]. Absorption of an oral solution proceeds rapidly with a tmax of 0.5 hour [18, 39]. The two enantiomers of etodolac show similar tmax values [40]. 

A reduction in particle size results in an increase in the surface area, which facilitates an increase in the dissolution rate and therefore, also, an increase in the rate of absorption. Drugs administered as suspension are generally rapidly absorbed because of the large available surface area of the dispersed solid. For solid dosage forms such as tablets and capsules, decreasing the particle size facilitates dissolution and thus absorption. Figure 6.8 shows the effect of particle size on absorption and resultant blood levels after oral administration of chloramphenicol in rabbits. Peak blood levels occurred much faster with the smaller... 

From pharmacology results and proposed clinical program, select route of administration (oral, pulmonary, intramuscular, subcutaneous, transdermal, ocular, vaginal, buccal, sublingual, etc.) and formulation type to be dosed (solution, suspension, tablet, capsule, granulation powder, microspheres, microemulsion, depot drug, etc.). 

Acetazolamide is readily absorbed from the gastrointestinal tract after oral administration. After ingestion of acetazolamide tablets, the drug attains peak plasma levels within 2 to 4 hours. Peak levels are maintained for 4 to 6 hours. Drug levels are higher after acetazolamide tablets are ingested than after an equivalent dose of the sustained-release formulation. The time-release capsules produce maximum drug levels in 3 to 4 hours, and levels of 10 mg/ml are maintained for approximately 10 hours. 

Chitin as a tablet/capsule disintegrant [48] Chitin is well known as a disintegrant in pharmaceutical solid dosage formulations in tablets to facilitate their breakup or disintegration after oral administration. Chitin, as a disintegrant, can be used at the 2-20% (w/w) level. 

Fig. 2 Summary of processes involved following the oral administration of a drug in tablet or capsule form. (From Blanchard, J. Gastrointestinal absorption. II. Formulation factors affecting bioavailability. Am. J. Pharm. 1978, 150, 132-151.)...

Factors affecting drug absorption include formulation, disease state, food effect, and drug-drug interaction. Formulations used for oral administration include solutions, suspensions, capsules, and uncoated and coated tablets. Depending on the formulation of a drug, the absorption characteristics may differ substantially. 

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