Pcol 1

Aqueous Diffusion

is the movement of a solute (drug) through a water-based environment, such as the blood or interstitial fluid.

Lipid diffusion

the movement of a solute (drug) through lipid-rich environments, such as cell membranes.

Endocytosis

process where cells engulf substances by forming vesicles around them. This is a key mechanism for the uptake of large molecules or particles.

Exocytosis

is the process of releasing substances from a cell by fusing vesicles containing those substances with the cell membrane.

Fick’s Law of Diffusion

fundamental law describing the rate of diffusion of a substance across a barrier.

Handerson-Hasselbalch Equation

an equation used to calculate the pH of a buffer solution. It's crucial for understanding the ionization state of drugs, which significantly impacts their absorption, distribution, and excretion.

IND (Investigational New Drug)

application submitted to the FDA (Food and Drug Administration) to begin clinical trials of a new drug in humans.

NDA (New Drug Application)

application submitted to the FDA for approval to market a new drug.

ANDA (Abbreviated New Drug Application)

An application submitted to the FDA to market a generic version of an already approved brand-name drug.

Orphan Drugs

Drugs developed to treat rare diseases that affect a small number of people. They often receive financial incentives and faster regulatory approval processes.

Receptor

protein molecule on the surface or within a cell that specifically binds to a signaling molecule (like a hormone or neurotransmitter), initiating a cellular response.

Agonist

A substance that binds to a receptor and activates it, mimicking the action of the natural ligand (e.g., a neurotransmitter).

Antagonist

A substance that binds to a receptor and blocks the action of the natural ligand or an agonist.

Competitive Antagonist

An antagonist that competes with the agonist for binding to the same receptor site. Its effects can be overcome by increasing the concentration of the agonist.

Physiological Antagonism

Two drugs that have opposite effects on the body, but act through different mechanisms. For example, a drug that lowers blood pressure and a drug that raises blood pressure.

cAMP (Cyclic Adenosine Monophosphate)

An important intracellular second messenger involved in many cellular processes, including signal transduction.

cGMP (Cyclic Guanosine Monophosphate)

Another important intracellular second messenger involved in various cellular functions, such as smooth muscle relaxation.

Potency

A measure of the drug concentration or dose required to produce a specific effect. A more potent drug produces the same effect at a lower dose.

Efficacy

The maximum effect that a drug can produce, regardless of the dose

LD50 (Lethal dose 50)

the dose of a drug that is lethal to 50% of the test animals. It's a measure of a drug's toxicity.

Effective Dose 50 (ED50)

The dose of a drug that produces a therapeutic effect in 50% of the individuals.

Clearance

The volume of blood from which a drug is completely removed per unit time. It's an important parameter in determining the dosing interval.

First Pass Elimination

is the metabolism of a drug by the liver before it reaches systemic circulation. This can significantly reduce the bioavailability of orally administered drugs.

Half-Life

The time it takes for the concentration of a drug in the blood to decrease by half.

Bioavailability

The fraction of an administered drug that reaches the systemic circulation unchanged.

Fick’s Law of Diffusion

It states that the rate of diffusion is proportional to the concentration gradient across the barrier.