B.Pharm 6 Sem. Biopharmacetics Unit 1 Part A Introduction to Biopharmaceutics

1. INTRODUCTION
TO
BIOPHARMACEUTICS
Prepared By
Girijesh Kumar Pandey
M.Pharm. (Pharmaceutics)

2. Contents
• Biopharmaceutics: Introduction
• Significance of Biopharmaceutics study

3. Biopharmaceutics: Introduction
• Biopharmaceutics: the study of how the
physicochemical properties of drugs, dosage forms and
routes of administration affect the rate and extent of
the drug absorption.
• Thus, biopharmaceutics involves factors that influence
the:
– 1) Protection and stability of the drug within the product;
– 2) The rate of drug release from the product;
– 3) The rate of dissolution of the drug at the absorption
site; and
– 4) The availability of the drug at its site of action .
Introduction to biopharmaceutics:

4. Biopharmaceutics: Introduction
• This discipline involves the complete
understanding of physical, chemical,
pharmacokinetic, pharmacodynamic and toxic
kinetic factors, which are likely to affect the
ADME profile of drug molecules.
• All these factors when governed thoroughly
leads to effective therapeutic concentration of
the drug in the biological fluids thus a
desirable action is seen.

5. Biopharmaceutics: Introduction
• Therefore, biopharmaceutics involves the study
of the relationship between the physicochemical
and biological factors affecting the in-vivo
behavior of the drug molecules.
• The complete knowledge of these variables not
only help in designing the drug delivery systems
but also helps in generating the sub-therapeutic,
therapeutic and toxic concentration of any drug
in biological fluids.

6. Biopharmaceutics: Introduction
• In general, for any drug molecule to be active
pharmacologically, it should have sufficient
aqueous solubility for dissolution, optimum oil
/ water partition coefficient to provide
diffusion through lipids and protein layers and
should have an active chemical group that
could interact with the receptor site.

7. Biopharmaceutics: Introduction
• But such ideal characteristics are not present
in any drug molecule thus require chemical
modifications. The overall process of clinical
response of any drug moiety is expressed by
the scheme given below:

8. Biopharmaceutics: Introduction
• From the above scheme, it is obvious that for any
clinical response the drug moiety should bear certain
physical characteristics like particle size, particle form,
solubility, partition coefficient and rheology.
• Also, certain chemical characteristics like coefficient
surface, effect of temperature, hydrolysis, oxidation
etc. are to be explored.
• Once physical and chemical characteristics are
expressed clearly, the biological factors like gastric
emptying, gastric pH, diet and glomerular filtration are
screened for clinical efficacy. Let us discuss the effect of
these factors one by one.

9. Significance of Biopharmaceutics study
• Biopharmaceutics explore the interrelationship of
the physical/chemical properties of the drug, the
dosage form (drug product) in which the drug is
given, and the route of administration on the rate
and extent of systemic drug absorption and the
use of this information to optimise the
therapeutic efficacy of the drug products.
• The process of movement of drug from its site of
administration to the systemic circulation is called
as absorption.

10. Significance of Biopharmaceutics study
• The concentration of drug in plasma and hence
the onset of action, and the intensity and
duration of response depend upon the
bioavailability of drug from its dosage form.
• Bioavailability is defined as the rate and extent
(amount) of drug absorption. Any alteration in
the drug’s bioavailability is reflected in its
pharmacological effects. Other processes that
play a role in the therapeutic activity of a drug are
distribution and elimination.

11. Significance of Biopharmaceutics
study
• The Biopharmaceutics Classification System (BCS) is a
scientific scheme that divides drugs according to their
solubility and permeability and has been used by
various guides as a criterion for biowaiver.
• The Biopharmaceutical Classification System is a
scientific schematic proposed by Amidon and
coworkers in 1995, which allowed the classification of
drugs based on solubility and intestinal permeability
parameters in four classes.
• The solubility and intestinal permeability are among
the main factors that govern the rate and extent of
drug absorption and therefore are directly related to
bioavailability.

12. Significance of Biopharmaceutics
study
• Biopharmaceutics explore the interrelationship of the
physical/chemical properties of the drug, the dosage
form (drug product) in which the drug is given, and the
route of administration on the rate and extent of
systemic drug absorption and the use of this
information to optimise the therapeutic efficacy of the
drug products.
• The concentration of drug in plasma and hence the
onset of action, and the intensity and duration of
response depend upon the bioavailability of drug from
its dosage form.
• Biopharmaceutics study provides confirmation of all
aspects of pharmacokinetic profiling of drug. Many
studies included like In-vitro–in-vivo co-relationships
etc. confirms success of drug product.

13. References
• Bio pharmaceutics and Pharmacokinetics-A Treatise, By D. M. Brahmankar
and Sunil B.Jaiswal, Vallabh Prakashan Pitampura, New Delhi.
• http://www.authorstream.com/Presentation/revathysreepathy-1301976-
biopharmaceutics/
• https://www.researchgate.net/publication/230785572_PHARMACEUTICA
L_TECHNOLOGY_Biopharmaceutics
• https://biopharma-biotherapeutics.alliedacademies.co m/2018/events-
list/biopharmaceutics-research-scope-and-prospects
• https://www.omicsonline.org/biopharmaceutics/biopharmaceutics-
importance.php
• https://www.uah.es/shared/es/estudios/estudios-
oficiales/grados/.galleries/Programs-En/570014_G57_2019-20_en.pdf
• https://www.researchgate.net/publication/287982797_Biopharmaceutics
_classification_system_Importance_and_inclusion_in_biowaiver_guidance
/link/57bd732708ae691824301e43/download