Jyothi

INTRODUCTION TO

PHYSICAL PHARMACY

BY-K.JYOTHIRMAI(084Q1R0024)

Physical pharmacy:-

Deals with Physical and Chemical properties of matter

MATTER:- Collection of Molecules

States Of Matter:-

1.Solid2.Liquid3.Gases

Factors Determining State Of Matter :-

1.Intensity of intermolecular forces2.Pressure3.Temperature

Gaseous state

Intermolecular forces of Attractions are weak

1. Ideal Gas Equation PV = nRT

2. Kinetic Molecular Theory E = 3/2 RT 3.Grahams Law Of Diffusion µ = √3p/ d

4.Vanderwal’s Equation For Real gases (P + a/V²) (V-b) = RT

5.Dalton’s Law Of Partial pressure P = P1 + P2 + P3 ………….

Applications of Gases: 1.Anesthetic Gases – Cyclopropane, Nitrous oxide

2.Sterilization Gases – Ethylene Oxide

3.Fuel Gases – Useful for Sealing of Ampoules Ex: Propane and Butane.

4.Gases in chemical Process – Hydrogen and Chlorine gases are used in

5.Hydrogenation and Chlorination Reactions.

6.Refrigeration Gases – Freon 12, Ammonia and Propane.

7.Compressed gas – Nitrogen, Nitrous Oxide. (Used in product such as

8.Dental creams, hair preparations etc...)

9.Liquefied gases - Dispense the medicament as a fine mist or Foam. Ex: Propellant 114

Liquid State

Methods Of Acheving liqueFaction :1. Faradays Method 2. Lindes Method3. Claude’s Method Characteristics Properties of Liquid:Dielectric ConstantSolubility ParameterViscosity Dipole MomentRefractive IndexSurface TensionOptical activity

Applications:

Clove Oil - AntisepticWater, Glycerin - Vehicles for Elixir, SyrupChloroform, Petroleum - Solvent for Extraction of DrugsHydroCarbons - Refrigerants

Solid State

It contains of ions, atoms & molecules which are held in fixed position and closely packed.

Classification1.Based on nature of bonds (Metallic,Ionic,Molecular)2. Based on structure (Crystalline,Non Crystalline)3. Based on physical properties (Isotropic,AnIsotropic)

Applications:

•Drug & Excipients are employed as Crystals.•Formulations in this state-easy for packaging & transportation.•Several dosage forms.•More stable.

Crystallinity is co-ordination of matter resulting from orderly cohesive three-dimensional arrangement. This is also called as Crystal lattice.

Crystal habit description of outer appearance of a Crystal.

Various forms of crystal: 1. Cubic - Sodium chloride 2. Tetragonal - potassium dehydrogenate phosphate urea 3. Hexagonal - Ice, Thymol 4. Orthorhombic - Barium sulphateBased on Crystal habit: 1. Plate - Naphthalene 2. Tabular - Tolbutamide 3. Equant - Sodium chloride 4.Cloumnar - Fluoro cortisone acetate

Crystal habit influences the followingPlate like crystals are easy to inject then that of needle like Flow properties and ease of compression

Crystalline Solids

Polymorphism

It is the ability of a compound to crystallize as more than one distinct crystalline species with different internal lattices

Ex:- chloramphenicol palmitate - A,B,C forms Phenobarbitone - form I, form II, form III

Applications:-Enhanced solubilityImproved dissolutionEnhanced absorptionManufacture of dosage forms

The polymorphic transitions can be presented by additives such as hydrocolloids and surface active agents which will poison the crystal lattice.

Liquid Crystal

These have the properties of both solids and liquids

They have liquid properties such as mobility and rotation and solid properties such as birefringence

The two main type crystals are

• Smectic [ soap or grease like]• Nematic [Thread like]

Nematic

Change In The State Of Matter:

Latent HeatVapour pressureVapour pressure- temperature Phase Diagrams:-

The phase diagrams help in selecting experimental conditions for transformations. Applications:•It is used in design and administration of Aerosol Products.•It is employed in distillation and purification methods.•It is used for freeze drying of pharmaceutical purpose and for evaporation in concentrating drugs.

Sub limitation – critical point:-

•In case of water, the temperature and pressure for triple point are 0.0098ºc and 610.25pa •Application

Freeze drying is used for manufacture of dosage forms involving biological, vacancies,sera and several antibiotics.

A B

c

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 Eutectic Mixtures(Eutectic Easy melting): Substances such as menthol, Thymol, camphor etc when mixed in particular proportion tend to liquefy due to reduction in their respective melting points.

This phenomenon is mainly used in pharmaceutical practice toimprove dissolution behavior of drugs.

For ex: Aspirin-acetaminophenAcetaminophen-propyphenazoneGriseofulvin-succinic acid

THANK YOU