The document discusses key topics in physical pharmaceutics including solute-solvent interactions, distribution laws, pharmaceutical buffers, physicochemical properties, surface tension, surfactants, intermolecular forces, and lyophilization. Specifically, it covers solubility expressions and factors, ideal and non-ideal solutions, types of solutions, and the importance of understanding physicochemical properties in drug formulation and development. The overall objective is for students to understand physicochemical principles and their application in designing drug dosage forms and formulations.

1. PHYSICAL PHARMACEUTICS-I

2. Learning Outcome
PHYSICAL PHARMACEUTICS-I
•Understand the mechanisms of solute solvent
interactions
•Study the limitations and applications
of Distribution law
•Learn the steps involved in the preparation of
pharmaceutical buffers and its importance
•Study the use of physicochemical properties
in formulation research and development

3. •Acquire skills and working knowledge of the
principles and concepts of surface tension and its
measurement
•Study the role of surfactants in various drug
delivery applications
•Understand the various intermolecular forces
involved in the formation of complexes and its
applications.
•Understand the pharmaceutical applications of
various techniques like lyophilisation

4. SPECIFIC LEARNING OUTCOMES
•List the various solubility expressions
•Explain the mechanisms of solute solvent
interactions
•Describe the ideal solubility parameters
•Describe the quantitative approach to the factors
influencing solubility of drugs
•Differentiate between ideal and non ideal solutions

5. Introduction
• Physical pharmaceutics is the branch of pharmacy that
concentrate on the application of physics and chemistry to study
of pharmaceutics.
• In other words, study of effect of dosage forms at molecular
level.
OBJECTIVE
• Understand various physicochemical properties of drug
molecules in the designing the dosage forms and in formulation
development.
• Know the principal of chemical kinetics & to use them for
stability testing and determination of expiry date formulation

6. Solubility of drugs
• SOLUTION
It is mixture of components which are physically and chemically
homogeneous.
• SOLUTE
The components which are present in the solution is called as
solute that dissolves in solvent.
• SOLVENT
The medium in which components are dissolved is known as
solvent.
• SOLUBILITY
The ability of substance to dissolve in a solvent is called solubility.

7. Types of solution
• SATURATED SOLUTION
The solution containing maximum number of solute at a
constant temperature is called saturated solution.
•SUPER SATURATED SOLUTION
A solution that contains more of the dissolved material
then could be dissolved by the solvent under normal
circumstances.
•UNSATURATED SOLUTION
A solution where the solute concentration is lower than its
equilibrium solubility.

9. SOLUBILITY
• Solubility is a intrinsic material property of the molecule while the Dissolution
is the extrinsic property.
• Solubility of drugs depends on the physical and chemical properties of both
the solute and solvent
• Temperature
• Pressure
• pH of the solution
• State of subdivision of the solute.
• In a quantitative way
It is the concentration of solute in a saturated solution at a certain temperature
• In a qualitative way
• It is the spontaneous interaction of two or more substances (solute & Solvent)
to form a homogenous molecular dispersion.

11. SOLUBILITY EXPRESSION