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
Read MoreBiomolecule Structure, Drug Design, and Cellular Processes
Biomolecule Structure Determination
Several methods exist for determining the structure of biomolecules. Here are two prominent examples:
X-Ray Crystallography
X-ray crystallography is a high-resolution technique analogous to microscopy. It allows visualization of protein structures at the atomic level, enhancing our understanding of protein function. We can study protein interactions with other molecules, conformational changes, and catalysis (in enzymes). This knowledge aids in designing novel
Read MorePlasmid DNA Purification in Bacteria
Lab #4: Purification of Plasmid DNA
Introduction
Plasmids are circular DNA molecules that constitute accessory genetic material and replicate independently of the host cell chromosome. They are naturally found in bacteria, with sizes ranging from approximately 5,000 to 400,000 base pairs (bp).
The information plasmids contain may confer upon their host cell traits such as antibiotic resistance, the capacity for degradation of aromatic compounds, or the fermentation of sugars, among others. The number
Read MoreEnzymes: Biological Catalysts and Their Mechanisms
Enzymes: Biological Catalysts
Enzymes are biological catalysts (proteins). They do not disturb the balance of the reaction. Enzymes contain an active site within the globular protein structure. They are highly specific. Specificity is determined by the complementarity between the active site and the substrate. They possess great catalytic power (106 or more) and are not permanently altered by the reaction.
The enzyme provides necessary proximity and orientation for the reaction to occur. There is
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