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
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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

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Understanding 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,

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Comprehensive 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/

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Exploring 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

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Matter: 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.

Mixtures

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