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INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD [email protected] 03-83137080
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Page 1: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

INTERMOLECULAR FORCES AND STATES OF MATTERPHAR 1313

Prepared by:

Wan Rosalina Wan Rosli, PhD

[email protected]

03-83137080

Page 2: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Learning objectives1.Describe the types of intermolecular forces2.Detail the physical characteristics of each state of matter3.Describe the mechanism involved in phase changes4.Describe the use of eutectics5.Relate and apply the use of the knowledge of intermolecular forces

and states of matter in current pharmaceutical practice

Page 3: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Intermolecular bond• Occur between molecules.• Weaker than covalent bonds.• Affect the physical and chemical properties of molecules.• Most important:

• Van der Waals forces• Hydrogen bonding

Page 4: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• A knowledge of intermolecular forces is important for understanding:• Stabilization of emulsions• Compaction of powders and granules in tablets• Drug action• Protein binding• Protein formulation and activity.

Page 5: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Van der Waal forces• There are 3 van der Waal forces of attraction:

1. Dipole-dipole forces (Keesom forces)2. Dipole-induced dipole (Debye forces)3. Induced dipole-induced dipole (Dispersion forces, London

forces)• Van der Waal forces are involved in solubility,

complexation, and numerous other physical bonding phenomena.

Page 6: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Dipoles• Dipole: a pair of equal positive and negative charges

separated by a small distance.

• If a molecule have separate regions of positive and negative charge, its dipole moment is permanent.

Page 7: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Dipole-dipole forces

• Molecules with permanent dipoles are polar.

• These molecules align themselves so that the negative pole of one molecule points to the positive pole of another.

• Example: water, HCl, acetone, phenol.

Page 8: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Dipole-induced dipole• A polar molecule can produce a temporary electric dipole

in nonpolar molecules that are easily polarizable.• Easily polarized molecules include ethylacetate,

methylene chloride and ether.

Page 9: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Induced dipole-induced dipole• A.k.a: London force, dispersion force.• Forces of attraction in nonpolar molecules originate from

the interaction between momentary dipoles.• Momentary electric dipoles arises from the asymmetry of

the electron distribution surrounding the nucleus of an atom.

Page 10: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Nonpolar molecules exhibiting induced dipole-induced forces of attraction include organic compounds such as carbon disulfide, carbon tetrachloride, and hexane.

Page 11: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Visualization of the induced dipole- induced dipole

Page 12: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Size of the induced dipole determines the strength of the dispersion interaction: the larger this dipole, the stronger the interaction.

• The size of the induced dipole depends on its polarizability (how much a given electric field will distort the electron distribution).

Page 13: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Example• Fluorine atoms (high ionization energy the electrons are

tightly held).• Thus, compounds containing many fluorine atoms tend to

have low polarizabilities, and so the dispersion interaction is weak. • Many fluoro compounds occur as gases at RT.

Page 14: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Which one is stronger, interaction between permanent dipoles or induced dipoles?• Induced dipoles

• Why?• The key point is that induced dipoles are always oriented so that

their interaction is favorable; this is not true for permanent dipoles.

Page 15: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Hydrogen bond• It is the attraction of a H atom for a strongly

electronegative atom such as oxygen, nitrogen, fluoride and sulfur.

Page 16: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Since any other atom will bind the electron from H atom more tightly, the electron will spend more time with the other atom. • This creates a permanent dipole (a partially exposed proton) that

can interact with other dipoles nearby.

Page 17: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Hydrogen bonding in water molecules account for properties of water:• Form aggregates: Liquid at RT• High Tm and Tb

Page 18: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Hydrogen bonding is also responsible for:• The conformation of proteins and DNA double helix structure.• Protein-ligand interaction• Solubility

Page 19: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

STATES OF MATTER

Page 20: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

What is matter?• Everything that take up space and have mass are

“Matter”.• It normally exist in one of the 3 states: solid, liquid or gas.

Page 21: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

States of Matter

Solid Liquid Gas

Definite mass & volume

Yes Yes No

Shape Fixed Take the shape of container

Fill all available space in container

Density High High Very low

Compressibility Relatively incompressible

Only slightly compressible

Compressible

Kinetic energy Low Medium High

Page 22: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Solids• There are 3 types of solids:

1. Crystalline

2. Amorphous

3. Polymers

Page 23: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

1. Crystalline• The atoms/molecules/ions are arranged in large

repetitious 3D units.• Have definite melting points (±1 or 2 degrees).• There are definite geometric form with 7 common

structures.

Page 24: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

7 crystal systems

Sodium chloride Urea Fluorapatite Calcite

ArgoniteSucroseCopper sulfate

Page 25: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Polymorphism• Some substance exist in >1 crystalline form

• The different forms are called “polymorphs” and the property is called “polymorphism”

• Two types of polymorphs:• Enantiotropic : Exist in MULTIPLE stable forms• Monotropic : Exist in only ONE stable form while other polymorphs

are unstable

Page 26: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Any pharmaceutical property of a solid will be influenced by its polymorphic form. Example:• Density • Melting temperature• Solubility• Dissolution rate• Chemical stability• Shelf-life

Page 27: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Example of polymorphic drugs

Drug No. of polymorphsChloramphenicol palmitate

4

Progesteron 2Caffeine 2Phenytoin 2

Page 28: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Pharmaceutical importance of polymorphism

• Exploitation of the polymorphic properties to design drug formulations.

• Example: use of cocoa butter as suppositories• Cocoa butter most stable polymorph is firm enough at

25°C but melts at 35°C.• If it is overheated (>40°C) and cooled quickly, it melts at

lower temperatures (15- 28°C)• Careful, slow heating produces suppositories that don’t

melt in hands but melt at body temperature.

Page 29: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Polymorphism has direct impact upon drug processability and drug quality/performance, (i.e stability, dissolution, and bioavailability). • May result in product development delay and commercial

production disruption

Page 30: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Effect of polymorphism

• Taken from http://www.chemistry-blog.com/2010/06/07/puzzling-polymorphs/ . Pictures from Org. Process Res. Dev., 2010, 14 (4), pp 878–882

Page 31: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Issues• Ritonavir (Norvir; Abbott) is a drug for treating patients

infected with HIV-1. • When it was first discovered in late 1992, ritonavir

crystallized as Form I. Ritonavir was marketed in 1996.• Early in 1998, some lots of ritonavir capsules failed the

dissolution test.

Page 32: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Investigations revealed a stable new form :Form II. • Accidental seeding

• The adverse effect on the bioavailability led to withdrawal of the products.

• A new formulation of ritonavir has to be developed.

Page 33: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

2. Amorphous

• Noncrystalline materials• No definite order or structure.• No definite melting point.• More soluble• Higher bioavailability than crystals

Page 34: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Some exist in both crystalline and amorphous forms. Example: petrolatum, insulin.

• Amorphous form used for prompt action and crystalline forms for long actions.

Page 35: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.
Page 36: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

3. Polymers

• Most are carbon based.• Example of pharmaceutical applications

• use as binders in tablets. • used as film coatings.• Modifies drug release characteristics 

• Example: Methylcellulose, polyethylene, polypropylene, polyvinyl alcohol, carbomer.

Page 37: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Liquids

• Surface tension is a physical property of pure liquids and solutions:

a) A molecule in the bulk liquid experiences cohesive forces with other molecules in all directions.

b) A molecule at the surface of a liquid experiences only net inward cohesive forces.

Page 38: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Surface tension ↓ when temperature ↑• Example of application:

• Solubility of powders in water is affected by high surface tension• Transdermal delivery of drugs can be optimized by controlling the

surface tension

Page 39: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Gases• The physical behavior of gases is independent of

the chemical nature of molecules• Therefore almost all gases respond in a similar way to

variations in pressure, temperature and volume.

• Properties of gases can be described using the various gas laws.• Boyle’s law• Charles’ law• Gay-Lussac’s law• Avogadro’s law• Ideal gas law

Combined gas law

Page 40: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Henry’s law• Henry’s law of gas solubility states that:

• the mass of gas dissolved in a given volume of solvent at constant temperature is proportional to the partial pressure of gas in the equilibrium with the solution.

• Partial pressure: • the pressure a gas would exert if it alone occupied the whole

volume of the mixture

• Example: carbonated drinks

Page 41: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Partial pressure

Page 42: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Application• Blood gases

• Gas plasma concentrations are related to atmospheric conditions and to biological and catalytic metabolic activity.

• Values are given as PO2, and PCO2.

• The partial pressure of O2 in the blood is on average about 80 mmHg and the partial pressure of CO2 is on average 35-45 mmHg.

Page 43: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• PCO2 is influenced by respiratory function.

• Reflect expiratory efficiency• If PCO2 ↑ : poor ventilation.

• If PCO2 ↓ : excessive ventilation/ hyperventilation.

*If patient have ↑PCO2 :respiratory acidosis (↓pH). If the reverse, patient may have respiratory alkalosis.

• Why?

Page 44: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

CHANGES IN THE STATE OF MATTER

Page 45: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Changes in the state of matter

Page 46: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Parameters involved in phase change

1) Vapour pressure• The pressure exerted by the liquid’s vapour when

the vapour is in equilibrium with the substance• Measures tendency of a material to change into the

gaseous state• Increases with temperature

Page 47: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Parameters involved in phase change

2) Boiling points• a liquid boils when the vapor pressure of the gas

escaping from the liquid is equal to the pressure exerted on the liquid by its surroundings

Page 48: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Parameters involved in phase change

3) Melting point and freezing point• Melting point a solid becomes a liquid• Freezing point a liquid becomes a solid• Theoretically both are the same temperature points but in

reality small differences can be observed.

Page 49: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Phase diagram• Phase diagrams is a type of graph that show the

equilibrium conditions between the distinct phases• It shows what phases are present in the material system

at various temperature, pressure, and compositions• Phase diagrams are used to illustrate phase changes.

Page 50: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Phase diagram

• Field: 1 phase, Line: 2 phase co-exist• The triple point: all three phases co-exist.• Critical Point is is the condition where it is no longer possible to

distinguish between the gas and liquid phases.

Page 51: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Gibbs Phase Rule• The rule describes the possible number of degrees of

freedom (F) in a closed system at equilibrium, in terms of the number of separate phases (P) and the number of chemical components (C) in the system

• Given by:

Page 52: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Phase, P, is a homogeneous portion of a system that has uniform physical and chemical characteristics.

• A phase can refer to a chemical or physical difference.• Two immiscible liquids separated by a distinct boundary

are counted as two different phases, as are two immiscible solids.

Page 53: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Degree of freedom, F, is the number of variables that can be changed independently without causing the appearance of a new phase or disappearance of an existing phase.• The variables must be parameters that are independent

of the amount of material in the system (eg. temperature, pressure, concentration and density)

Page 54: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Component, C, is the minimum number of chemical constituents necessary to define the composition of each phase present at system equilibrium

• The number of components is not always easy to determine at first glance, and it may have to be determined experimentally.

Page 55: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Why is phase rule useful?• Helps to characterize state of the system• Predict equilibrium relations of phases• Helps to construct phase diagrams• To standardize the system so that it will produce standard

products• Standard production of medicine

Page 56: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Example• In the reaction of heat decomposition of calcium carbonate:

• There are three phases.• There are also 3 different chemical constituents, but the number of components is 2 because any two constituents completely define the system in equilibrium. • Any third constituent may be determined if the

concentration of the other two is known.

Page 57: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• Substituting into the phase rule we can see that the system is univariant

F = C – P + 2 = 2 – 3 + 2 = 1. • Therefore only one variable, either temperature or

pressure, can be changed independently.

Page 58: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Example 2

How many intensive variables can be independently specified at the triple point of water ?

• Number of chemical species present, C= 1 • Number of phases present at equilibrium, P= 3

F = 1 - 3 + 2= 0

NO variables can be independently specified at the triple point! This means that there is just one triple point and ALL of the properties of all of the phases are fixed. The triple point is unique.

Page 59: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Eutectics• A eutectic system is a mixture of chemical compounds or

elements that has a single chemical composition that solidifies at a lower temperature than any other composition made up of the same ingredients. • This composition is the eutectic composition and the temperature is

the eutectic temperature.• Intersection of both is the eutectic point.

Page 60: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Example

• In addition of A to B or B to A, melting points are reduced.

• At a particular composition: eutectic point is reached have the lowest melting point than A or B.

• Used to increase drug solubility

Page 61: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Application• The mixture, AB is made at eutectic composition: A low

soluble drug (A%) + inert soluble carrier (B%)• B% is more than A• Solid AB prepared by rapid cooling of A+B in order to

obtain a physical mixture of very fine crystals of the two components.

Page 62: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

• When this mixture is dissolved in an aqueous medium, the carrier will dissolve rapidly, releasing very fine crystals of the drug.

• The large surface area of the resulting suspension should result in an enhanced dissolution rate• Improved bioavailability.

Page 63: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

Example• An eutectic mixture of drug and soluble carrier.• The carrier dissolves and leaves the drug in a fine state of

solution in vivo, usually in a state which predisposes to rapid solution.

• Eg: griseofulvin the eutectic solid of griseofulvin-succinic acid dissolves 6-7 times faster than pure griseofulvin

Page 64: INTERMOLECULAR FORCES AND STATES OF MATTER PHAR 1313 Prepared by: Wan Rosalina Wan Rosli, PhD rosalina@cybermed.edu.my 03-83137080.

THANK YOU


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