1. FORMULATION FACTOR EFFECTING
DRUG ABSORBTION
Presented by
PRIYANKA GRESESS ANAND
M.Pharm
Department of Pharmaceutics
INTEGRAL UNIVERSITY
LUCKNOW U.P
3. Introduction
• To gain entry in to the blood circulation,a drug
must be solubilize to pass from the absorbtion
site through biological membranes.
• Permeability of drug through biological
membranes is closely related to the molecular
structure of the drug,physicochemical
characteristics,formulation factor ,and the
physical and biochemical properties of the cell
membrane.
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4. DRUG ABSORBTION
Definition
Drug absorbtion is a pharmacokinetic parameter that
refers to the way a drug is absorbed from a
pharmaceutical formulation in to the bloodstream.
In general,lipid soluble drugs composed of smaller
molecules are more likely to absorbed .
the rate and extent of absorbtion mostly depends on
routes of administration and the way a drug product is
designed and manufactured.
.
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5. Dosage forms like tablet, capsule, powder, solution,
suspension, emulsion may vary the absorption.
Drug products that contain the same drug (active
ingredient) may have different inactive ingredients so
absorbtion of these drug from different products may
flactuate.
Absorbtion play a key role in determining how fast a
drug produces a clinical effect.
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6. Formulation Factor which can slower the rate of
absorbtion of drug are mentioned below –
Formulation Factors:-
Manufacturing variables: -
a). Method of granulation
Wet granulation yields a tablet that dissolves
faster than those made by other granulating
methods. But wet granulation has demerit like
formation of crystal bridge or chemical
degradation.
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7. b)-compression force-Higher compression force
yields a tablet with greater hardness hence have a
long D.T. but on other hand higher compression
force cause crushing of drug particles into
smaller ones with effective surface area which
decreasesD.T..
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9. Drug formulations are designed to provide an
attractive, stable, and convenient use of
products.
Decreasing order dissolution rate of different
dosage forms as :-
solutions>solid solutions>suspensions,
capsules>coated capsules>tablets, and
controlled release formulations.
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Solutions
Solutions shows faster absorption as compared to
solid dosage forms.
solutions are frequently used as bioavailability
standards.
Factor effecting absorbtion of solution:-
Viscosity
Solubulizer
Stability
surfactants
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Suspensions
• A drug in a suspension is in solid form, but is
finely divided and has a large surface area.
• Drug particles can diffuse readily between the
stomach and small intestine so that absorption
is relatively insensitive to stomach emptying
rate.
• Liquid dosage forms, therefore, have
advantages besides simple dissolution rate.
However, they also have some disadvantages,
including greater bulk, difficulty in handling, and
perhaps reduced stability.
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Capsules and tablets
• These formulations differ from each other in
that material in capsules is less impacted than
in compressed tablets.
• Once a capsule dissolves, its contents generally
disperse quickly.
• Tablets generally disintegrate in stages, first into
granules and then into primary particles. As
particle size decreases, dissolution rate
increases due to of increased surface area..
14. Diluents
Diluents are commonly added to tablet and
capsule formulations if the required dose is
inadequate to produce bulk.
Eg:-Drug-diluent interaction resulting in poor
bioavailability of tetracycline & DCP
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15. Binders and granulating agent
Promote cohesive compacts before & after compression
Eg polymeric materials like starch, cellulose derivatives, acacia,
PVP, etc.
COLOURANTS
Very low concentration of water-soluble dye has inhibitory effect on
dissolution.
E.g. brilliant blue retards dissolution of sulfathiazole
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16. Lubricants
To aid flow of granules
To reduce interparticle friction
Sticking of particles to dies & punches
Eg:- sodium and magnesium stearates &
waxes.
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17. DISINTEGRANTS
These Agents overcome cohesive strength of tablet & break them on
contact with water which is an important for tablet to dissolve.
eg MCC
BUFFERS
They create right atmosphere for dissolution
e.g. buffered aspirin tablets
Buffer containing potassium cations inhibit the drug absorption
e.g. vitamin B2 & sulphanilamide
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18. SURFACTANTS
They may enhance or retard drug absorption
1. Promotion of wetting & dissolution of drugs
2. Better membrane contact of drug for absorption
3. Enhanced membrane permeability of the drug
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19. Product age and storage conditions
• Product aging and improper storage
conditions adversely affect B.A.
E.g. –precipitation of drug in solution
decrease rate of drug dissolution
& absorption .
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20. CONCLUSION
• Absorption plays an major role to attain the desired
therapeutic action with minimal side effects at the given
period of time.
• Formulation factors influencing drug absorption helps us to
focus on formulating drug with proper attainment of
permeability of drugs to systemic circulation at given time
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21. REFERENCE
• 1. Brahmankar D.M., Jaiswal S.B., First edition,
“Absorption of Drugs” Biopharmaceutics and
Pharmacokinetics – A treatise, Vallabh Prakashan, Delhi
1995, Page No. 5-75.
• 2. Shargel L., Andrew B.C., Fourth edition “Physiologic
factors related to drug absorption” Applied
Biopharmaceutics and Pharmacokinetics, Prentice Hall
International, INC., Stanford 1999. Page No. 99-128.
• 3. Pharmaceutics , the Science of Dosage form Design By
M.E. Aulton
• 4. Swarbrick J., Boylan J.C., “Absorption” Encyclopedia
of Pharmaceutical Technology, Marcel Dekker, INC., New
York 1988:1-32.
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