Topic 3

Question 1

what are physicochemical properties

Answer 1

The physicochemical properties of an active pharmaceutical substance are the physical and chemical reactions involved in the formation of all changes in the structure of atoms and molecules and the interaction affects the active ingredient kinetics

Physicochemical properties refer to the physical and chemical characteristics of a substance that define its behavior and interactions under various conditions

each type of dosage form requires a careful study of the API substances physical and chemical (physicochemical) properties

Question 2

what are the eight physicochemical properties

Answer 2

particle size and surface area
solubility
Dissolution
Partition coefficient and pKa
Crystal properties: polymorphism
Stability
Organoleptic properties
Other properties

Question 3

what is particle size and surface area

Answer 3

By reducing the size of the particle, it increases the surface area of the active ingredient

The following are dependent on the particle size of the active ingredient:
Dissolution rate
Absorption rate
Dosage form content uniformity
Stability

The dissolution rate is the time it will take for the medicine to dissolve

Absorption rate is the time it will take for the medicine to be absorbed into the bloodstream

Dosage form content uniformity is how even the active ingredient will be distributed through the dosage form example through the tablet

Stability is the time, preferably in yours before the active ingredients starts to lose its effectiveness in the dosage for

In many cases for both active ingredients and additives it is necessary to reduce particle size to achieve the desired physicochemical reaction

Question 4

what is solubility

Answer 4

The maximum amount of a solid (API) that can dissolve in a solvent

It is important that an active ingredient has some solubility in water to ensure a therapeutic effect

An active ingredient is chemically formulated in a soluble salt derivative to achieve solubility

Question 5

Techniques to increase solubility in active ingredients (three)

Answer 5

Micronising (reducing diameter of a solid materials particles)

complexation (combining individual atom groups, ions or molecules to create one large ion or molecule)

Solid dispersion (mixing the drug with an inactive substance (carrier) in a solid form using heat, solvents or both to help it dissolve better)

Question 6

Techniques to increase solubility in active ingredients (three)

Answer 6

Micronising
complexation
Solid dispersion

Question 8

what is dissolution

Answer 8

The process by which an active ingredients particles dissolve.

Before an active ingredient can be absorbed it must first dissolve in the fluid at the absorption site

Question 9

Explain the process of dissolution

Answer 9

Dissolution is how a drug dissolves in the body so it can be absorbed.

1.	First, the outer layer of the drug starts to dissolve in the surrounding fluid.
2.	This creates a small area around the drug called the “diffusion layer,” which is full of the dissolved drug.
3.	The drug then moves from this layer into the rest of the body fluid and travels toward the place where it gets absorbed (like the lining of the stomach or intestines).
4.	As the dissolved drug moves out, more of the drug from the tablet dissolves, and the process keeps going until the whole drug is absorbed.

Think of it like sugar dissolving in tea — first the outer part melts into the tea, then it spreads out, and more sugar keeps dissolving until it’s all mixed in.