What is the principle of biotransformation?

Biotransformation is the metabolic conversion of endogenous and xenobiotic chemicals to more water-soluble compounds.

What are the factors affecting drug absorption?

What is drug biotransformation?

Biotransformation is a metabolic process that takes place mainly in the liver and helps to facilitate the excretion of both exogenous and endogenous substances. A series of reactions alter the chemical structures of these substances.

Why stereochemistry is important in drug metabolism?

Stereochemistry influences not only the disposition and activity of the parent drug but also the nature and potential pharmacological activity of the metabolites formed. Many recent developments are furthering our understanding of drug metabolism and the implications of stereochemistry.

Why are most drugs metabolised and not excreted?

The majority of metabolic processes that involve drugs occur in the liver, as the enzymes that facilitate the reactions are concentrated there. The purpose of metabolism in the body is usually to change the chemical structure of the substance, to increase the ease with which it can be excreted from the body.

Why do I metabolize drugs so quickly?

Some drugs are chemically altered by the body (metabolized)... read more ) drugs slowly. As a result, a drug may accumulate in the body, causing toxicity. Other people metabolize drugs so quickly that after they take a usual dose, drug levels in the blood never become high enough for the drug to be effective.

What is drug absorption in pharmacology?

Drug absorption is a pharmacokinetic parameter that refers to the way a drug is absorbed from a pharmaceutical formulation into the bloodstream. Image Credit: By NOOMEANG / Shutterstock. Several factors can affect the absorption of a drug into the body. These include: physicochemical properties (e.g. solubility)

How are most drugs eliminated from the body?

Most drugs, particularly water-soluble drugs and their metabolites, are eliminated largely by the kidneys in urine. Therefore, drug dosing depends largely on kidney function. Some drugs are eliminated by excretion in the bile (a greenish yellow fluid secreted by the liver and stored in the gallbladder).

What happens if a drug is not metabolized?

If your body metabolizes a drug too slowly, it stays active longer, and may be associated with side effects. Because of this, your doctor may characterize you as being one of four metabolizer types, with respect to a specific enzyme. Poor metabolizers have significantly reduced or non-functional enzyme activity.

What are the 3 phases of drug action?

Drug action usually occurs in three phases: Pharmaceutical phase. Pharmacokinetic phase. Pharmacodynamic phase.

What are the factors that may influence the rate of absorption?

What are the benefits of biotransformation?

The advantages of using biotransformations for these types of reactions is the ability to operate under mild conditions, hence retaining the traditional properties of the dairy products. Enzymes that can remove "sticky dextrins" during baking have also been investigated at Food and Crop Research (Every 1994).

What are the barriers to drug absorption?

An aqueous stagnant layer that overlies the apical membrane and the subepithelial blood flow are potential barriers to the absorption of drugs that readily penetrate the absorbing cell of the epithelium. The apical, basal, and basement membranes are potential barriers to the absorption of less permeable drugs.

How does drug concentration affect absorption?

The most common mechanism of absorption for drugs is passive diffusion. This process can be explained through the Fick law of diffusion, in which the drug molecule moves according to the concentration gradient from a higher drug concentration to a lower concentration until equilibrium is reached.

What is the most important factor that affects rate of absorption of a medication?

Solubility and permeability are considered as the major physicochemical factor that affect the rate and extent of oral drug absorption, moreover other physicochemical properties always show their effects to drug absorption via affecting solubility and permeability.

How are drugs metabolized in the body?

Most drugs must pass through the liver, which is the primary site of drug metabolism. Once in the liver, enzymes convert prodrugs into active metabolites or convert active drugs into inactive forms. The liver's primary mechanism for metabolizing drugs is a specific group of cytochrome P-450 enzymes.

Which of the following is the correct decreasing order of drug metabolism?

Of most of the drugs. It is because it has most of the enzymes in it that are in large numbers. Metabolism by other organs is very less because they have a very low quantity of enzymes present in them. Thus the order is liver > lungs > kidneys > intestine > placenta > skin > adrenals .

Which tissue has the greatest capacity to Biotransform drugs?

Liver is the tissue which can do transformation and biotransformation of synthetic and non-synthetic drugs, organic and non-organic nutrients and micro molecules and macro molecules.