Drug Delivery Systems: A Comprehensive Guide to Pharmaceutical Formulations
Colloids and Gels
Disperse Systems
- Molecular (<1mm): Oxygen molecules, ions, glucose
- Colloidal (1nm-500nm): Polymers, cheese, butter
- Coarse (>500nm): Sand in water, red blood cells
DLVO Theory
- Attractive Forces: Result from van der Waals forces, which are caused by dipole-dipole interactions.
- Electrostatic Repulsion: Results from electrical double layers on each particle.
Colloidal Drug Delivery Systems
- Micelles: Solubilize poorly water-soluble compounds.
- Microemulsions: Deliver oil-soluble drugs via
Understanding Water Hardness and Treatment Methods
What is Water Hardness?
Hardness of water is a property that prevents the lathering of soap. This is due to the presence of certain salts of calcium, magnesium, and other heavy metals dissolved in the water.
When hard water is treated with soap (sodium or potassium salt of higher fatty acids like oleic, palmitic, or stearic acid), it doesn’t produce lather but forms a white precipitate. This precipitate is formed due to the formation of insoluble soaps of calcium and magnesium.
Types of Hardness
There
Read MoreUnderstanding Corrosion: Types, Causes, and Prevention
Understanding Corrosion
Corrosion is a more complex process than simple oxidation. It’s a galvanic process occurring between a metal and its environment, leading to deterioration. This deterioration manifests as:
- Ruptured exhaust pipes and mufflers in cars
- Failing domestic water heaters
- Gas leaks and explosions in storage tanks or pipelines
- Breaks in water pipes
- The collapse of bridges and other structures
The Electrochemical Process of Corrosion
Corrosion involves a metal interacting with its surroundings,
Read MoreComprehensive Chemistry Notes: From Basic Concepts to Reactions
Chemistry Notes
Measurements
Time = s > stopwatch
Temperature = degree Celsius/ Kelvin(K) > thermometer
Mass = kg > electronic balance
Volume = cm^3/ m^3/ dm^3 > gas syringe
Common Laboratory Apparatus for Measuring Volume
Beaker/ Measuring Cylinder = approximate volume
Pipette/ Burette = exact volume
Pipette = fixed volume
Burette = varying volume
Gas Collection Methods
Downward Delivery = gases denser than air
Upward Delivery = gases less dense than air
Displacement of Water = gases that are insoluble/
Read MoreExploring the Atom: From Ancient Theories to Modern Discoveries
What is an Atom?
Atoms are microscopic particles that form everything around us. They are organized in the periodic table of elements. This is part of the atomic theory, which states that:
- All elements are made up of tiny particles invisible to the human eye.
- Atoms of the same element are identical in terms of size and mass.
- Atomic elements can be combined to create new substances.
- No matter can be created or destroyed, only joined or separated.
John Dalton is credited with proposing the atomic theory
Read MoreMatter: Properties, States, and Transformations
Properties of Matter
Matter is anything that has mass and occupies space. Properties are the characteristics of a substance. Substances can have both physical and chemical properties. Transformations are the changes that can be observed in matter over time.
States of Matter
Matter exists in three states:
- Solid: Rigid and dense with a definite shape and volume.
- Liquid: Dense and fluid, takes the shape of the container.
- Gas: Like a very low-density fluid – takes the shape and volume of the container.