Biopharmaceutical Classification system. A major system to classify the medicines based on its permeability and solubility. Detail explanation on the same. Specifically for the regulatory requirements. Work as material for MPharm RA students under PCI syllabus.

1. INTRODUCTION:-
Biopharmaceutical Classification System
(BCS) system allows restricting the
prediction using the parameters solubility
and intestinal permeability.
The tenets of biopharmaceutics, solubility
and permeability, are of pivotal importance in
new drug discovery and lead optimization.

2. Expands the regulatory application of
the BCS and recommends methods for
classifying drugs.
Explains when a waiver for in vivo
bioavailability and bioequivalence studies
may be requested based on the approach of
BCS.

3. Biowaiver are based on the
Biopharmaceutics (BCS) classification of
the active ingredient.
Currently BCS class I and some class III
compounds are eligible for biowaivers.
 The drug substance should be highly
soluble and highly permeable.

4.  An immediate release drug product
should be rapidly dissolving.
 The drug should not be a narrow therapeutic
index drug.
 Excipients used in the dosage form
should have been used previously in
FDA approved IR solid dosage forms.

5. 1. The Biopharmaceutical Classification System
has been developed to provide a scientific
approach to allow for to prediction in vivo
pharmacokinetics of oral immediate release
(IR) drug product by classifying drug
compound based on their,
SOLUBILITY
PERMEABILIT
DISSOLUTION

6. The Maximum Amount of solute dissolved in
a given solvent under standard conditions of
temperature, pressure and pH.
Solubility is the ability of the drug to be
solution after dissolution.
 The higher single unit dose is completely
soluble in 250 ml at pH 1- 6.8
( 37˚C ).

7.  Permeability of the drug to pass the biological
membrane which is the lipophilic.
Permeability is indirectly based on the extent
of absorption of a drug substance.
Drug substance is considered to be highly
permeable, when the extent of absorption in
human determined to be 90%.

8. It is process in which solid substance solubilises in
given solvent i.e mass transfer from solid surface to
liquid phase.
Using USP apparatus I at 100 rpm or USP apparatus
II at 50 rpm.
 Dissolution Media [900 ml],
1. 0.1N HCl or simulated gastric fluid (pH
1.2) without enzyme.
2. pH 4.5 buffer & pH 6.8 buffer.
3. Simulated intestinal fluid without enzyme.

9. CLASS SOLUBILITY PERMEABILITY EXAMPLES
Class-I High High
Metoprolol ,
Propranolol
Class-II low High
Nifedipine,
naproxen
Class-III High Low
Cimitidine,
Metformin
Class-IV Low Low
Taxol,
Clorthiazole

10. Ideal for oral route administration.
Drug absorbed rapidly.
Drug dissolved rapidly.
Rapid therapeutic action.
Bioavailability problem not expected for
immediate release drug product.
e.g. Metoprolol , Propranolol, Diltiazem.

11. Oral route for administration.
Drug absorb rapidly.
Bioavailability is controlled by dosage form
and rate of release of the drug substance.
e. g. Nifedipine, naproxen.

12. Oral route for administration.
Drug absorbance is limited.
Drug dissolve rapidly.
e. g. Cimitidine, Metformin, Insulin.

13. Poorly absorbed by orally administration.
Both solubility & permeability limitation.
Low dissolution rate.
Slow or low therapeutic action.
e. g. Taxol, Chlorthiazole, Cefexime
Trihydrate.

14.  To use in biowaiver considerations.
 Aid in earliest stages of drug discovery
research.
 Applications in both the preclinical
and clinical drug development
processes.
 To predict in vivo performance of drug
product using solubility and permeability
measurements.