Preformulation
Preformulation:
Definition:
·
It can be defined as an investigation of physical and
chemical properties of a drug substance - alone and or when combined with
excipients.
·
Preformulation is
a link between drug discovery and drug development.
·
It is the first
step in the rational development of dosage form of drug substance.
Objectives
·
To establish the physico-chemical
parameter of new drug entity.
·
To develop the elegant dosage forms
(stable, effective & safe}
·
It is important to have an
understanding of the physical description of a drug substance before dosage
form development.
·
It is 1st step in rational development
of a dosage form of a drug substance before dosageform development.
Goals
·
To
establish the physico-chemical parameters of new drug substance.
·
To
establish the physical characteristics
·
To
establish the kinetic rate profile.
·
To establish
the compatibility with the common excipient.
·
To
choose the correct form of a drugsubstance.
PREFORMULATIONPARAMETERS:
1.
PHYSICAL
CHARACTERISTICS.
ii.
Bulk
characteristics
a.
Solid
state characteristics
c.
Densities
d.
Compressibility
e.
Crystalline
f.
Polymorphism
iii.
Solubility
analysis
a.
Ionization
constant(Pka)
b.
Partition
co-efficient
c.
Solubilization
d.
Thermal
effect
e.
Common
ion effect(Ksp)
f.
Dissolution
iv.
Stability
analysis
a.
Solution-state
stability
b.
Solid-state
stability
c.
Drug-excipients
compatibility
2.
CHEMICAL
CHARACTERISTICS
i.
Hydrolysis
ii.
Oxidation
iii.
Photolysis
iv.
Recemization
v.
Polymerization
vi. Isomerization
Comments
Post a Comment