DRUG PRODUCT PERFORMANCE,
IN VITRO

SUBMITTED BY :

ANKIT KUMAR MALIK

SUBMITTED TO :
DR. SANJULA BABOOTA MA’AM
DR. JAVED ALI SIR

DEPARTMENT : Pharmaceutics

School Of Pharmaceutical Education and Research
JAMIA HAMDARD

The solid oral dosage forms should have good quality and better
characteristics for performance. This depends on appropriate
appearance of the product, its potency, its stability and dissolution
of the product.

The characterization of drug product performance, in-vitro is vital
as it provides information about the potency of active ingredients

Drug product performance studies are used in the development of
new and generic drug products.

CONT
D.

This process is also vital as it gives information about the development of
formulation, assessment of comparability, control and assurance of quality.

The characterization of the potency and rate of release by in-vitro testing
in the oral dosage form is based on chapters and monographs mentioned in
the pharmacopoeia of the United States of America.

In-vitro test for the active ingredient to release from the dosage form is
based on:-

Disintegration of product
Dissolution of active ingredient

IN VITRO DISSOLUTION OF DRUG
PRODUCT IS BASED ON FACTORS LIKE:-

1. Drug substance related factors
2. Factors related to formulation
3. Factors related to manufacturing process
4. Factors related to dissolution test apparatus

DRUG SUBSTANCE RELATED
FACTORS

Dissolution refers to the process of solubilization of the drug into the dissolution medium.
Dissolution process is controlled by the affinity between the solid and the dissolution
medium.
Noyes and Whitney in 1897 proposed a fundamental equation for dissolution:-

dm/dt = K X (Cs – Ct)
dm/dt = rate of dissolution
k = proportionality constant or dissolution constant
Cs = concentration at saturation
Ct = concentration at time t

Factors are:-
Drug solubility
Polymorphism
Salt factor
Surface area and particle size

DRUG SOLUBILITY

The drug substance solubility of a drug is related to the dissolution rate of drug.

Higher dissolution rates are given by drugs which have high solubility.

The solubility of compounds containing “ionizable groups” is a function of the pH of
the dissolution media and pKa of the compound.

Solubility of a drug is determined using an equilibrium solubility method and involves
suspending an excess amount of solid drug in selected aqueous medium.

POLYMORPHISM OF DRUG
When a drug substance :-

existing in two or more crystalline phases that have different arrangement/conformation of the molecule in
the crystal lattice
having different hydrate forms
Having amorphous phases which do not possess a distinguishable crystal lattice

Dissolution rates of drugs having various polymorphic form are effected due to different
lattice energies of the polymorphs which have different solubility.
Crystalline form has less solubility than the amorphous form due to fixed and compact lattice
structure
Example :- Two polymorphic forms of Chloramphenicol palmitate exist which are A and B,
form B is better orally absorbed than form A due to greater solubility.

SALT RELATED FACTORS OF DRUG

Unionizable molecules are less water soluble as compared to the organic
salts which offers a criterion for improving the rate of dissolution.

So, during the development of drug salts of weak bases and
weak acids are chosen .

Example :- The non-steroidal anti-inflammatory drug ‘Naproxen’ was
originally marketed as a free acid for the treatment of rheumatoid or osteo-
arthritis.

FACTORS RELATED TO
FORMULATION

Drug product dissolution is greatly affected by the excepients which are used in the
formulation.

For dosage forms which are for immediate release, those excepients are are used which help in
enhancing the dissolution rate.

Disintegrants like sodium starch glycolate and croscarmellose facilitate the deaggregation and
promote the breakup of tablets into granules.

 The disintegrants effect is to provide an increased surface area of the drug particle and hence
promoting dissolution.

Surfactants can also be included to increase the dissolution rates e.g. sodium lauryl sulphate.

MANUFACTURING PROCESS FACTORS

Several manufacturing variables can affect the drug product dissolution characteristics
so here, manufacturing strategies may be employed to enhance dissolution rates.

For example, spray drying of the active ingredient with excipients such as polyvinyl
pyrrolidine (PVP) can be used to generate stabilized amorphous dispersions, which have
greatly accelerated dissolution rates.

Improved wetting of hydrophobic drug surfaces and enhanced dissolution rates are
sometimes achieved by employing wet granulation vs. dry granulation processes, during
product manufacture.

DISSOLUTION TEST FACTORS
The dissolution test parameters such as:-

Apparatus type

Rotation speed

Dissolution medium pH

Volume

IN VITRO DRUG PRODUCT
PERFORMANCE EVALUATION

Disintegration test :-

It is a qualitative test.

An official disintegration apparatus, the USP basket rack assembly, is used to
perform the test, which is generally applicable only to immediate-release products.

When product dissolution is rapid (defined by ICH as dissolution NLT 80% in 15min
at pH 1.2, 4.0, and 6.8) and the dosage form contains drugs that are highly soluble
throughout the physiological range, disintegration testing may be meaningful.

The ICH Guidance considers a drug substance to be highly soluble when the
highest dose strength is soluble in 250mL or less of aqueous media over the pH
range of 1.2-6.8.

DISINTEGRATION APPARATUS

DISSOLUTION TEST
The test quantitatively measures the amount of active drug that dissolves from the
dosage form in a liquid dissolution medium using standard dissolution apparatus and
procedures.
Apparatus

Apparatus 1 (basket) and 2 (paddle), the apparatus most commonly used for studying the
dissolution of solid oral dosage form. The basket at 100 rpm is commonly used for testing capsules,
and the paddle at 50 rpm for tablets.

Media
The selection of a dissolution test medium is based on the physico-chemical properties of the drug
substance and characteristics of the dosage form.
Media with pH ranging from 1.2 (gastric pH) to 6.8(intestinal pH) are generally preferred.
The most common media used in dissolution testing are water, 0.1N hydrochloric acid, pH 4.5
acetate buffer, and pH 6.8 phosphate buffer.
The temperature of the dissolution bath is usually maintained at 37 0.5C to reflect human body
temperature

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Tolerance
The dissolution test acceptance criterion, or tolerance, is specified in terms of the quantity (‘‘Q’’)
that is dissolved within a specified time interval.
for most oral dosage forms, 75% or 80% (‘‘Q’’) of the labelled amount of the active drug ingredient
is specified to be dissolved within a set time duration (test times between 15 and 60min are most
common).

DISSOLUTION TESTER

APPLICATIONS OF IN VITRO
DISSOLUTION

Product Development
In vitro dissolution is an important and useful tool during the development of a
dosage form. In vitro dissolution often aids in guiding the selection of prototype
formulations and for determining optimum levels of ingredients to achieve drug
release profiles.

Product Stability
In vitro dissolution is also used to assess drug product quality with respect to
stability and shelf life.
As products age, physicochemical changes to the dosage form may alter the
dissolution characteristics of the drug product over time.
For example, as the moisture level increases or decreases over time, this can result
in altered tablet hardness and subsequent possible changes in dissolution
characteristics.

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THANK YOU