Different routes for the protein and peptide drug delivery (Oral, Buccal, Nasal, Transdermal, Parental and pulmonary)

1. Protein And Peptide Drug Delivery System
PRESENTED BY:
MEGHA
ASSISTANT PROFESSOR

3. Routes
Oral route Buccal Route Nasal Route
Pulmonary
Route
Parenteral
Route
Transdermal
Route
Rectal
Route

5. 1) ORAL ROUTE :-
 Oral route is the most popular route of delivery from the patient’s point of
view. Main advantages of this route are convenience, acceptability and high
patient compliance.
 The main barriers to successful oral delivery of protein and peptides are
similar to that of traditional drug candidates, but these are more pronounced
in the case o fpeptide/protein moieties.
The main barriers to effective oral delivery are :-
 Poor intrinsic permeability of peptides/proteins across biological membranes.
 Susceptibility to enzymatic attack by intestinal proteases and peptidases.
 Rapid post-absorptive clearance.
 Physical instability like aggregation and adsorption.

6. Chemical
modification
Penetration
Enhancer
Carrier System
Enzyme
Inhibitor
Amino acid
modification
Lipidation Liposomes
Emulsion
Lipid Based
Polymer
based
Hydrogels
Nanoparticles
Various approaches that are developed for delivery proteins and peptide drugs

7. a). CHEMICAL MODIFICATION :-
 The Chemical Modification of Protein and Peptide Drug is Important to
Improve the Enzymatic Stability as well as Membrane Permeations.
a.1) Amino acid modification:-
 Post-translational modifications can occur on the amino acid side chains or
at the protein's C-or N- termini .They can extend the chemical repertoire of
the 20 standard amino acids by modifying an existing functional group or
introducing a new one such as phosphate.
 Phosphorylation is a very common mechanism for regulating the activity of
enzymes and is the most common post-translational modification.
Amino acid
(polar)
Phosphorylation Amino acid
( non-polar)

8. a.2) Lipidation:-
 Attachment of lipid molecules to the protein structure.
Hydrophobic groups for membrane localization:-
 Myristoylation , attachment of myristate.
 Palmitoylation , attachment of palmitate.
 Isoprenylation or prenylation, the addition of an isoprenoid group.
Cofactors for enhanced enzymatic activity:-
 Lipoylation, attachment of a lipoate functional group.
 Flavin moiety may be covalently attached.

9. b) Penetration Enhancer:-
 Peptide/protein drug moieties, due to their molecular size, often
require penetration enhancers to achieve therapeutically significant
levels of luminal absorption.
 Penetration enhancers is responsible for the Disruption of the
Mucosal Barriers.
Surfactant Polysorbate , SLS, Pluronic F-68
Chelating agent EDTA
Bile salt sodium cholate and deoxycholate
Mucoadhesive
polymeric system
Thiomers , Cellulose derivatives
Other example Fatty acids, Phospholilpid

10. C) Carrier System:-
 This strategy is particularly applicable in the case of poorly absorbed
peptides/proteins, which are unstable in the Gastro intestinal (GI) lumen
and their targeting to a specific tissue or organ is to be affected.
 The proper designing of the delivery system not only protects the drug from
gastrointestinal degrading components in the physical environment of the
formulation prior to absorption, but also localized the drug at or near the
cellular membrane to maximize the driving force for passive permeation.
C.1) lipid based carrier system:-
C.1.1) Liposomes :-
 Liposomes are spherical, self-closed structure formed by one or several
lipid bilayer with an aqueous phase inside.

11. Liposomes are biocompatible and can both entrap and protect the protein and
peptide in their internal core.
 To deliver liposomes to the brain, they can be firstly modified into long
circulation vesicles by decreasing particle size (< 100 nm) or by linking
polyethylene glycol (PEG) chains to their surface.
Method of Preparation
Liposome

12. C1.2) Emulsion:-
An emulsion is a well-blended mixture of two immiscible liquids such as oil
and water in the presence of emulsifying or surface-active agents .
Multiple emulsions such as oil in-water-in-oil (O/W/O) and water-in-oil-in-water
(W/O/W) emulsions are often used for delayed or controlled drug release.
Self-nanoemulsifying drug delivery systems (SNEDDS) have received
considerable attention as a promising alternative to orally administered
emulsions due to their high physical stability and ease of manufacture.
SNEDDS consist of oils, surfactants, co-solvents/co-surfactants, and drugs.
Compared to conventional W/O/W emulsions, SNEDDS have some
advantages as an oral delivery system for protein drugs in terms of better
stability, better oral bioavailability, and easier particle size control.

13. Protein
SNEDDS

14. C.2) Polymer Based Carrier System:-
C.2.1) Hydrogels :-
 Hydrogels are three-dimensional polymeric networks composed of cross-
linked hydrophilic and biocompatible polymers, which also exhibit a
thermodynamic compatibility with water allowing them to swell in aqueous
media.
 Among various polymers, 2-hydroxyethyl methacrylate, ethylene glycol
dimethylacrylate, N-isopropyl acrylamide, acrylic acid, methacrylic acid (MAA),
polyethylene glycol (PEG) and polyvinyl alcohol (PVA) are commonly used in
hydrogels for protein delivery.
 Alginate and xanthan gum-based hydrogel systems seem to be suitable for
protein delivery via the oral route of administration.

15. C.2.2) Nanoparticles:-
Nanoparticles are solid, colloidal particles consisting of macromolecular
substances that vary in size from 10 nm to 1000 nm.
Typically, the drug of interest is dissolved, entrapped, adsorbed, attached
and/or encapsulated into or onto a nano matrix.
Polymers are used in the preparation of nanoparticles:-
 Polylactic acid (PLA),
 Polylactic-co-glycolic acid(PLGA)
 Chitosan
 Gelatin,
 Polymethylmethacrylates
 Poly-alkyl-cyanoacrylate.

17. D) Enzyme Inhibitor:-
In addition to direct modifications, another method to increase oral peptide
bioavailability is to coadminister with enzyme inhibitors.
These enzyme inhibitors are usually more effective in the large intestine
than the small intestine due to the large quantity and variety of proteases in
the small intestine.
Insulin with enzyme inhibitor (Aprotinin, bacitracin, betatin) which result in
significance reduction in insulin digestion and improve in its intestinal
absorption profile
Enzyme inhibition compound
Metalloprotease EDTA
Aminopeptidases Bestain & Bacitracin
Metalloendoprotease Phosphoramidon
Cystinyl Proteases Papain, Endopeptidase

19.  Buccal membrane has numerous elastic fibers in the dermis, which is
another barrier for diffusion of drug across the buccal membrane.
 The barriers for efficient drug absorption are:
 Mucus layer covering the oral epithelium.
 Epithelial barriers.
 Peptidases in the saliva and the mucus layer and microbial flora.
 The buccal peptide absorption is assumed to be via passive absorption
mechanism.
 Various parameter that influence the extent of buccal peptide absorption are
molecular weight, polarity, conformation, dissociation and enzymatic and
chemical stability.
2.) Buccal Route :-

20. various strategies employed for Buccal Delivery
Adhesive
tablets
Adhesive
patches
Adhesive gels
a.) Adhesive Tablets:-
 Buccal tablets are small, flat and oval, with a
diameter approximately 5-8 mm. They soften,
attach to the mucosa, and are retained in
position until dissolution and release is
complete.
 These tablets can be applied to different
sites in the oral cavity, including the
palate,the mucosa lining the check, as well
as between the lip and the gum.

21. b). Adhesive Gels :-
 Viscous adhesive gels have been designed for local therapy using polyacrylic
acid and polymethacrylate as gel forming polymers.
 Gels are reported to prolong residence time on the oral mucosa to a
significant level. This not only improves absorption but also allows for
sustained release of the active principle.
C). Adhesive Patches :-
 Patches are laminates consisting of an impermeable backing layer, a drug-
containing reservoir layer from which the drug is released in a controlled
manner, and a bioadhesive surface for mucosal attachment.

22. Formulation of Mucoadhesive buccal Film
Formulation of Mucoadhesive buccal Film
API
Bioadhesive
polymer
Plasticizer
Penetration
Enhancer
Backing
membrane
Agarose
chitosan
gelatin
hyaluronic acid
Polyacrylates
polyoxyethylene
glycerol,
propylene
glycol,
PEG 400,
castor oil
Polysorbate
EDTA
sodium cholate
and deoxycholate
Thiomers
Cellulose
derivatives
carbopol
magnesium
stearate
HPMC
HPC
CMC

24. 3.) Nasal Route:-
Generally, the intranasal route is suited for the intermittent delivery of highly
potent peptide/protein drugs having low molecular weight.
 Peptidal drug moieties like calcitonin, ACTH, and interferon are reported to
have appreciable absorption through nasal mucosa.
Nasal route is chiefly use to delivery of protein drug.
Barriers to systemic absorption through nasal route :-
 Extent of absorption varies with the mucus secretion and mucus turnover.
 Peptidases and proteases present in the mucus or associated with nasal
membrane serve as enzymatic barrier in protein/peptide absorption.
Types of
Dosage Form
Nasal Spray Aerosol Nasal Drops

25. Various approaches for Nasal Delivery of peptide/protein
drugs
Increase
nasal blood
flow
Permeation
enhancer
and enzyme
inhibitor
Dissociation
of
Aggregation
pH
Modification
Viscosity
modification
a.) Viscosity modification :-
The clearance time from the nasal cavity can be delayed by using solutions
with higher viscosity.
For example the half time of clearance could be increased significantly with
0.6 % of hydroxypropyl methylcellulose.

26. b). pH Modification:-
 Peptides and proteins usually exhibit the lowest solubility at their isoelectric
point. Thus, by adjusting the pH further away from the isoelectric point of a
particular peptide, its solubility can be increased.
 For example nasal absorption of insulin was observed with sodium
deoxycholate, that insulin is capable of crossing the nasal membrane in an
acidic medium.
 Examples of buffer used in nasal spray sodium phosphate, Sodium citrate,
citric acid.
c). Dissociation of Aggregation:-
 Proteins are likely to form higher-order aggregates in solution.
 For instance at pH 7.0, protein exists in solution chiefly as hexameric
aggregates

27.  Protein fails to cross the nasal membrane.
 Sodium deoxycholate disrupts the formation of protein hexamer or
dissociation of protein hexamer to dimer or monomer.
d). Permeation enhancer and enzyme inhibitor :-
They increase the fluidity of the lipid bilayer membrane and open up
aqueous pores as a result of calcium ion chelation.
 Peptidase inhibitors enhance the absorption by suppressing peptidase
activity in both the mucus and mucosal cells.
Enzyme inhibitor Permeation enhancer
EDTA
Bile Salts
Polysorbate
EDTA
sodium cholate and
deoxycholate
Thiomers
Cellulose derivatives

28. e). Increase Nasal flow:-
 With an increase in local nasal blood flow an enhancement in nasal peptide
absorption has been reported. This occurs due to concentration gradient of
peptide passive diffusion.
 Vasoactive agents, which are known to enhance nasal blood flow, include
histamine, prostaglandin E1 and beta-adrenergic agonist.
Different nasal delivery systems like drops, sprays and inhalers have variable
results in terms of intensity, duration of effect. Nasal drops produce far greater
pathologic changes and faster clearance than the nasal sprays and inhalers.
Metered dose aerosol and metered dose pump can achieve accurate dose
dispensation and good distribution in the nasal cavity.
Delivery system :-

30. 4.) Transdermal Route:-
 Transdermal is a route of administration wherein active ingredients are
delivered across the skin for systemic distribution.
Advantages of Transdermal Route for peptide/protein Delivery are:
 Better and improved patient compliance.
 Elimination of hepatic first pass phenomenon.
 Controlled administration is possible and thereby avoidance of toxic effects.
Also drugs with shorter half-life can be administered.
Limitations of Transdermal Route for peptide/protein Delivery are:
 A low rate of permeation for most protein drugs due to their large molecular
weight and hydrophilicity and lipophilic nature of the stratum corneum .
 High intra and inter patient variability.

31. Various approaches for Transdermal delivery Route of
peptidal drugs
Iontophoresis Sonophoresis Electroporation
Microneedle
technology
a).Iontophoresis:-
 Iontophoresis is a method that induces migration of ions or charged
molecules when an electric current is allowed to flow through an electrolyte
medium.

32.  To undergo Iontophoresis protein/and peptide
molecules must carry charge. To achieve this
pH and ionic strength of solution are controlled.
Protein/and peptide are repelled by the same
charge on electrode and penetrate through the
skin under the influence of electric current.
 The two electrodes are placed on the stratum
corneum, one of the electrode drug is loaded
(reservoir electrode) and current is applied
which increased the permeability of skin and
drug molecule flow through epidermis →→→
dermis→ papillary layer →→ subdermal
tissue→→blood circulation
Iontophoresis

33. b) Electroporation :-
Electroporation utilizes very short pulses of high voltages (between 10 and
100 V) to perforate the skin.
Similar to iontophoresis , application of electroporation breaches only the
stratum corneum, characterizing it as another non-invasive method for drug
introduction.
Application of an electric current disrupts the structure of these lipids, allowing
molecules to penetrate the skin. In addition, delivery of drug can be increased
using this method by increasing the voltage, number of pulses and duration of
pulses to levels still viewed as safe for the patient.

34. c). Sonophoresis :-
Sonophoresis, also referred to as cavitational ultrasound, relies on the
application of sound waves to the skin to increase its permeability.
Sonophoresis achieves this task by targeting the lipid bilayers embedded in
the stratum corneum.
Sound waves, generally between 20–100 kHz, are believed to cause an
increase in pore sizes on the skin (increased fluidity in these lipid bilayers),
thus allowing drug penetration transcellularly through the stratum corneum

35. d). Microneedle technology:-
Microneedle technology involves the use of small needles that create small
pores in the skin, allowing drug passage across the outermost physical barrier.
 These microneedles are designed to breach only the stratum corneum.
Methods :-
One such method involves a two step approach, where the needles are used
to puncture the skin to create pores, followed by topical administration of the
drug.
Another method includes coating the microneedles themselves with drugs,
allowing the drug to then enter the body after the skin is treated with the
needle.
A third method includes encapsulating the drug in biodegradable
microneedles, slowly releasing the drug as the needles degrade.

36. Microneedle Technique

38. 5.)Parenteral Route :-
 Parenteral mode of drug delivery has been the major route of choice for
protein/peptide, owing to their poor absorption and metabolic instability when
given by other alternative routes.
 The parenteral drug delivery system includes Intravenous, intramuscular,
subcutaneous, intraperitoneal, intrathecal use.
Carriers System
Liposome
Nano particles
Microsphere Emulsion

39. MISCELLANEOUS
Self regulated
system
On demand
system
Pump
Mechanical
pump
Osmotic pump

40. a). On Demand System :-
 Externally augmented demand delivery systems are particularly beneficial in
the delivery of polypeptides like insulin.
 The device consists of an ethylene-vinyl acetate matrix with magnetic beads
or cylinders.
 The magnetic beads alternately compress and expand the matrix in the
presence of magnetic field.
 On exposure to external oscillating magnetic field the drug release was
increased up to 30 times. On removal of the magnetic field, the drug release
rates returned to normal.

41. b.)Pumps:-
 Pumps differ from other diffusion based system in that primary driving force
for delivery is the pressure difference and not the concentration difference of
the drug between the formulation and the surroundings. Pressurizing the drug
reservoir, by osmotic action or by direct mechanical actuation, can generate
this pressure difference to affect drug release. The pump can either be
implantable or externally portable.
b.1) Mechanical pumps:-
Mechanical pumps are technically simple,
rugged and can be easily manipulated to
deliver Peptidal drugs in several different
wave form. But the prime concerns are in
terms of its susceptibility to mechanical
failure, high power requirement and
relatively large size.

42. b.2) Osmotic pumps:-
 Osmotic Pump have been used extensively for delivery of a large number
of peptide/proteins drugs in animals. These pumps can be implanted
subcutaneously. Some of the representative examples of drugs that have
been delivered in osmotic pumps include insulin, ACTH, calcitonin, LHRH,
growth hormone, neurotensin and vasopressin

43. C) Self regulated system:-
Glucose sensor sense
the Glucose level
Transmit Signal to the
insulin Pump
Then sensor transmit
signal to stop the insulin
pump
Insulin Pump deliver
Insulin to infusion set

44. Thank You