Transdermal drug administration involves the application of drugs to the skin for systemic absorption, while oral, intravenous, and intramuscular are all common routes of drug administration.

Intravenous drug administration delivers the drug directly into the bloodstream, resulting in a rapid onset of action.

Transdermal patches are designed to deliver drugs through the skin over an extended period of time, providing sustained-release drug delivery.

Enteric-coated tablets are designed to resist stomach acid, protecting the drug from degradation and ensuring its release in the small intestine.

Drug absorption from the gastrointestinal tract can be influenced by various factors, including food intake, pH of the stomach, and the presence of bile salts.

Drug distribution throughout the body primarily occurs via diffusion, a passive process where drugs move from areas of high concentration to areas of low concentration.

Drug distribution in the body can be influenced by various factors, including protein binding, the blood-brain barrier, and tissue perfusion.

The primary route of elimination for most drugs is renal excretion, where drugs are filtered by the kidneys and excreted in urine.

Drug elimination can be influenced by various factors, including age, gender, and liver function.

Half-life refers to the time it takes for the concentration of a drug in the body to decrease by half.

Suppositories are not a common type of solid oral dosage form, as they are typically administered rectally or vaginally.

Liquid dosage forms are generally easier to administer, especially for patients who have difficulty swallowing solid dosage forms.

Ointments, creams, and gels are all commonly used for topical drug delivery, as they can be applied directly to the skin.

Parenteral dosage forms, such as injections, provide a rapid onset of action as the drug is directly introduced into the bloodstream.

Bioavailability of a drug can be influenced by various factors, including dosage form, route of administration, and first-pass metabolism.