What is absorption and distribution?

What is absorption and distribution?

Absorption: Describes how the drug moves from the site of administration to the site of action. Distribution: Describes the journey of the drug through the bloodstream to various tissues of the body.

What are the 5 processes of pharmacokinetics?

Pharmacokinetics is the movement of a drug through the body’s biological systems, these processes include absorption, distribution, bioavailability, metabolism, and elimination. It can be used to study the onset, duration, and intensity of the effect of a drug.

What are the 4 pharmacokinetic principles?

There are four main components of pharmacokinetics: liberation, absorption, distribution, metabolism and excretion (LADME). These are used to explain the various characteristics of different drugs in the body.

What are the factors affecting absorption?

Factors affecting Absorption of Drugs

• Lipid water solubility. Lipid water solubility coefficient is the ratio of dissolution of drug in lipid as compared to water.
• Molecular size.
• Particle size.
• Degree of Ionization.
• Physical Forms.
• Chemical Nature.
• Dosage Forms.
• Formulation.

What are different factors that affect absorption?

What is absorption pharmacokinetics?

The most important principle in pharmacokinetics theory is drug absorption which is defined as the transportation of the unmetabolized drug from the site of administration to the body circulation system. The bioavailability of a drug product is known as the rate and extent of its absorption.

What is the difference between PK and PD?

The main difference between pharmacokinetics and pharmacodynamics is that pharmacokinetics (PK) is defined as the movement of drugs through the body, whereas pharmacodynamics (PD) is defined as the body’s biological response to drugs.

What are the main requirements for drug absorption process?

For drug absorption to occur, a drug must cross biologic barriers (e.g. epithelial/endothelial cells, etc.). Only a few drugs move across cellular barriers in an “active” way; that is, a way that requires energy (ATP) and moves the drug from an area of low concentration to an area of higher concentration.

How does area of absorbing surface affect drug absorption?

Area of absorptive surface affects oral as well as other routes. Most of the drugs are given orally because of the large area of absorptive surface, so that greater absorption occurs. Similarly, when the topically acting drugs are applied on a large surface area, they are better absorbed.

What are biopharmaceutical factors?

The biopharmaceutical factors, which influence the interaction between dosage form and drug activity, extend from the mode of application, through chemical and physical properties of the active constituent, to the final product, including the excipients and manufacturing processes involved.

What are the factors that affect absorption?

Solubility is the primary factor affecting absorption. Insoluble salts and ionized compounds are poorly absorbed, whereas lipid-soluble substances are generally readily absorbed, even through intact skin.

How are drugs distributed in the body after absorption?

After absorption most drugs are distributed in the blood to the body tissue where they have their effect. The degree to which the drug is likely to accumulate in the tissue is dependent on the lipophilicity and local blood flow to the tissue. Highly perfused organs receive most of the drugs.

How are toxins absorbed from the body?

Absorption may occur through the GI tract, skin, lungs, via the eye, mammary gland, or uterus, as well as from sites of injection. Toxic effects may be local, but the toxin or toxicant must be dissolved and absorbed to some extent to affect the cell.