Drug Administration: Routes, Pharmacokinetics, and More
Routes of Administration
The three primary routes of administration for frequently reported drugs are:
- Parenteral and cigarette use with heroin.
- Nasally, in the case of cocaine and stimulants.
- Smoked: Like hashish.
- Ingested by mouth: Alcohol and synthetic drugs.
- Aspirated: Such as cocaine and speed.
- Inhaled: As adhesives.
- Injected: Sometimes as heroin.
Classification (Rang HP, Dale MM…)
Routes of drug administration can be classified into four groups according to the place of drug deposition:
- Enteral: Via
Enzymes in Recombinant DNA Technology: A Detailed Look
Enzymes in Recombinant DNA Technology
Let’s delve into the enzymes used in recombinant DNA (rDNA) technology:
1. Restriction Endonucleases (Restriction Enzymes)
- These enzymes recognize specific DNA sequences, known as restriction sites, and cleave the DNA at these sites.
- Restriction enzymes are named after the bacteria from which they were originally isolated, such as EcoRI (from Escherichia coli) and HindIII (from Haemophilus influenzae).
- They generate DNA fragments with cohesive (sticky) or blunt ends,
Cellular Transport and Membrane Specialization
Cellular Transport
The plasma membrane allows selective permeability. This is achieved because the lipid bilayer acts as a barrier. Transport:
Passive Transport
Passive transport does not require energy. It is the process where molecules move spontaneously down a concentration gradient, from an area of higher concentration to an area of lower concentration across the membrane.
- Simple Diffusion: Direct passage through the lipid bilayer.
- Facilitated Diffusion: Transport through membrane proteins.
- Channel
Advanced Drug Delivery Systems: Principles and Applications
Basic Concepts in Drug Delivery
Drug delivery refers to methods used to administer pharmaceutical compounds for therapeutic effects. The goal is to enhance bioavailability, improve efficacy, enable targeted release, and optimize administration routes. Drug names include chemical (precise structure), generic (officially recognized), trade (brand-specific), and street names. Delivery strategies include passive targeting (e.g., liposomes accumulate in tumors via Enhanced Permeability and Retention (
Pharmacokinetics and Drug Action: Key Concepts Explained
Why Elderly May Experience Increased Sleepiness with Morphine
Elderly individuals, similar to children, often have reduced hepatic activity. This means that drugs like morphine take longer to be metabolized and eliminated from the body, potentially leading to increased drowsiness even after withdrawing the drug.
Drug Molecule Characteristics for Crossing Physiological Barriers
Drugs with smaller, non-ionized, and lipid-soluble molecules can easily cross physiological membranes via passive diffusion.
Read MoreEnzyme Action: Lock-and-Key and Induced-Fit Models
Enzymes are proteins that serve as catalysts in chemical reactions. A catalyst is any substance that speeds the rate of a chemical reaction. Enzymes lower the activation energy needed to start a chemical reaction. Enzymes are typically uniquely structured to facilitate one specific reaction. The active site is where substances bind, and the chemical reaction is initiated, forming the product.
There are two main types of mechanisms of enzyme action:
- Lock-and-key model
- Induced-fit model
Lock-and-Key Model
This
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