This document discusses bioavailability, prodrugs, and drug delivery. It defines bioavailability as the rate and extent to which an active drug reaches systemic circulation. Prodrugs are biologically inactive compounds that release the active drug within the body via chemical or enzymatic transformation. The goals of prodrug design include improving formulation, enhancing permeability and absorption, changing distribution profiles, and overcoming toxicity issues. Drug delivery systems aim to transport pharmaceuticals as needed to safely achieve therapeutic effects, and current trends involve targeted delivery and sustained release formulations.

1. Name:-Umangi Thakkar
Roll no:-062
Topic:-BiOAVAIBLITY, Prodrugs and Drug
Delivery

2. What is Bioavailability
• Bioavailability, indicates measurement of the rate and extent(amount)of
therapeutically active drug that reaches the systemic circulation and is
available at the site of action.
Concept of Bioavailability:-
• Rate and extent at which therapeutically active drug reaches systemic
circulation.
• The fraction of administrated dose that reaches the systemic circulation
in contrast to that stated on label.
• Rate and extent of absorption of unchanged drug from its dosage form.
•

3. Objectives
1. Development of new formulations.
2. Determination of influence of excipients, patient related
factors and possible interaction with other drugs on rhe
efficiency of absorption.
3. Control of quality of a drug product during the early
stages of marketing in order to determine the influence of
processing factors,storage,stability on drug absorption.
4. Primary stages of the development of a suitable dosage
from for a new drug entity.

4. Prodrugs
• The concept of prodrug is first introduced by Adrian albert in 1958 to
describe the compound undergo biotransformation prior to eliciting
their pharmacological effect.
• Prodrug is defined as a biologically inactive derivative of a parent
drug molecule that usually requires a chemical or enzymatic
transformation within the body to release the active drug,and possess
improved delivery properties over the parent molecule
• The development of prodrugs is now well established as a strategy to
improve the physicochemical,biopharmaceutical or pharmacokinetic
properties of pharmacologically potent compounds,and thereby
increase usefullness of a potential drug.

6. Rational for prodrug design
A)Improving formulation and adminstration.
B)Enhancing permeability and absorption.
C)Changing the distribution profile.
D)Protecting from rapid metabolism.
E)Overcoming toxicity problems

7. Properties of ideal prodrug

8. Classification of Prodrug.

9. A)Carrier linked prodrug
• Carrier linked prodrug consists of the attachment of a carrier group to the active
drug to alter its physicochemical properties.
• The subsequent enzymatic or non-enzymatic mechanism release active drug moiety.

10. 1.Bipartite prodrug
• It is composed of one carrier(group)attached to the drugs.
• Such prodrugs have greatly modified lipophicity due to the attached
carrier.The active drug is released by hydrolytic cleavage either
chemically or enzymetically.
• Eg.Tolmetin-Glycine prodrug.

11. Tripartite prodrug.
• The carrier group ia attached via linker to drug.

12. Drug delivery
• Drug delivery systems refers to approaches,formulations,technologies, and
systems for transporting a pharmaceutical compound in the body as needed
to safely achieve its desired therapeutic effect.
• Based on two basic parameters:
A) Route of entery.
B) Dosage form.
• Method of drug delivery:-significant effect on efficacy.
• Current trend :-Targeted delivery & Sustained release formulations.