Different approaches for delivery of protein, peptides & vaccines PRESENTED BY : SHIKHA SINGHROLL NO :160617009UNDER THE GUIDANCE OF: DR. M SREENIVASA REDDYPROFESSOR & VICE PRINCIPALMCOPS MANIPAL UNIVERSITY

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CONTENTSIntroduction of protein & peptides

Challenges in delivery of protein & peptides

Different approaches for delivery of protein & peptides

Introduction of vaccines

Delivery systems used to promote the uptake of vaccines

Controlled release micro-particles for vaccine development

Conclusion

References

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INTRODUCTIONWhat are proteins & peptides?

Proteins are relatively large molecules with complex structure

Peptide chains in peptides & proteins are seldom linear & adapt a variety of specific folded 3D patterns & conformations

All peptides & proteins are polymers of amino acids connected via amide linkages referred to as peptide bonds

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CHALLENGES IN DELIVERY OF PROTEIN & PEPTIDES

DEGRADATION

1. PHYSICAL

Denaturation Aggregation Adsorption Precipitation

2. CHEMICAL

Deamination Oxidation Proteolysis Disulphide exchange B-elimination

POOR STABILITY

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Conti…3. BARRIERS Enzymatic Barriers

Hydrolytic cleavage

Intestinal Epithelial

Capillary Endothelial

Blood Brain barrier

4. FOOD PROTEIN INTOLERANCE

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APPROACHES FOR DELIVERY OF PROTEIN & PEPTIDESOral route

Buccal route

Nasal route

Transdermal route

Pulmonary route

Parenteral route

Ocular route

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Oral route

Barriers

Poor intrinsic permeability of peptides/proteins across biological membrane

Susceptibility to enzymatic attack by intestinal proteases & peptidases

Rapid post-absorptive clearance

Physical instability like aggregation & adsorption

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Approaches for oral delivery of protein & peptide drugs

Modification by chemical synthesis of Prodrug & its analogueApproach 1• Eg PEG derivative Monosaccharide derivative

Use of enzyme inhibitorApproach 2• Eg Metalloprotease inhibited by EDTA

Use of penetration enhancer Approach 3• Eg EDTA, SLS

Carrier system Approach 4• Eg Nanocarrier, microparticle, Emulsion w/o/w & bioadhesive system

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Buccal routeBarriers for efficient drug absorption are

1. Mucus layer

2. Epithelial barriers

3. Peptidases in saliva & microbial flora

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Factors affecting buccal routeMolecular weight

Polarity

Conformation

Dissociation

Enzymatic

Chemical stability

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Approaches for buccal delivery of protein & peptides

Adhesive tablets

Adhesive patches

Absorption promoters

Adhesive gels

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Nasal routeBarriers to systemic absorption through nasal route

a) Extent of absorption varies with the mucus secretion & mucus turnover

b) Peptidases & proteases present in the mucus or associated with nasal membrane serve as

enzymatic barrier in protein/peptide absorption

c) Alteration in absorption profile in diseased conditions like allergic condition & chronic

rhinitis & URTI

d) Penetration enhancers & preservatives may damage mucosal cell membrane & may even

be ciliotoxic

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Type of dosage formNasal spray

Nasal drops

Aerosol

Various approaches for Nasal Delivery of peptide/protein drugs are:◦ Viscosity modification - 0.6% HPMC◦ PH modification – insulin permeates in acidic conditions◦ Permeation enhancers – SLS◦ Increase nasal blood flow ◦ Drug delivery design

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Transdermal routeLimitations of Transdermal Route for peptide/protein Delivery are:

A low rate of permeation for most protein drugs due to their

1. Large molecular weight

2. Hydrophilicity & lipophilic nature of the stratum corneum

High intra & inter patient variability

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Approaches for transdermal delivery of protein & peptides

Approaches:

1. Iontophoresis - insulin, vasopressin

2. Phonophoresis – insulin, erythropoietin

3. Penetration enhancer - Oleic acid, dimethylsulphoxide

4. Prodrugs – TRH, LHRH

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Pulmonary routeParticles that reach the alveoli can be absorbed into the systemic circulation, avoiding first pass metabolism & the harsh conditions of the gut

The deep lung delivery offers the following benefits:

Provides a direct route to the circulation

Reduction in dose requirement up to 50 fold & thus a cost effective option

Fast absorption

Safe route for drug entry even in patients with lung diseases

No triggering of immune functions

Increased patient compliance with a minimum of discomfort & pain

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Major challenges in pulmonary drug delivery Variation in absorption rates due to variation in epithelial line thickness under physiological

condition

Delivery to the lung should be precise & consistent at every inspiration

Site of dose deposition to the deep lung

Aerodynamics of aerosolized particles

Reproducibility in dose deposition

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Parenteral routeIt is major route of choice for delivery of protein & peptide drug

The parenteral drug delivery system includes IV, IM, subcutaneous, intraperitoneal,

intratheacal routes, etc

Drug carrier system employed for definite & controlled delivery of drug through this route are

1. Particulates

2. Soluble carriers

3. Miscellaneous system

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Drug carrier systemA. Particulates

1. microspheres 2. nanoparticles3. nanoparticles 4. liposomes5. emulsions6. cellular carriers

B. Soluble carriers (macromolecules)

C. Miscellaneous 1. Self-regulated 2. systems Pump

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Ocular routeViscosity of formulation play important role to increase contact time & increase bioavailability of the drug

Various polymer used in ophthalmic preparation the first approach in ocular drug delivery system is that to prolong contact time by incorporating various polymer

Eg :PVA, PVP, MC, CMC, HPMC, other bioadhesive polymer eg carbopol, sodium alginate, etc

Barrier to ocular route is

1. Tear dilution

2. Lacrymal drainage

3. Protein binding

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Approaches for ocular delivery of protein & peptidesApproaches:

1. Ocular inserts

2. Absorbable gelatin sponge

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Company Product name Technology Formulation product

Apollo Life Science Oraldel Nanoparticles Tablet Insulin, TNF-blocker

Emisphere Eligen Penetration enhancers Tablet Calcitonin, insulin

Nobex/Biocon HIM2 Pegylation Liquid Insulin, enkephalin, calcitonin

Generex Oral–Lyn ™ Penetration enhancers

Spray devices ,

aerosol particlesInsulin, Macrotonin

Provalis PLC Macrulin™Lipid based

microemulsionEmulsion Insulin, Salmon

calcitonin

NOVEL TECHNOLOGIES:

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NAME PRODUCT COMPANY STATUS

Exubera Inhaled insulin powdered Pfizer & CO FDA approved

Aerodose Inhaled insulin solution Aerogen and diestro medical system Phase 2 completed

HIIP Inhaled insulin powdered Eli lilly & CO In Phase 2

Rapid mist oralin Mouth spray for buccal delivery Generex biotechnology Completed phase 2 trials

Emisphere tablet Emisphere Phase 2 completed

NIN-058 tablet Nobex corporation and glaxosmithkline Phase 2 in progress

Patch Insulin patch Altea development corporation Phase 1

EXAMPLES OF MARKET TRENDS

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VACCINE DRUG DELIVERY SYSTEM

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INTRODUCTIONA vaccine is a biological preparation that improves immunity to a particular disease

A vaccine typically contains an agent that resembles a disease-causing microorganism & is

often made from weakened or killed forms of the microbe, its toxins or one of its surface

proteins

Vaccines can be prophylactic or therapeutic

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DELIVERY SYSTEMS USED TO PROMOTE THE UPTAKE OF VACCINES

1. ABSORPTION ENHANCERS

Increases absorption by enhancing membrane permeation, rather than increasing solubility

Also termed as permeation enhancer

Absorption enhancers are functional excipients included in formulations to improve the

absorption of a pharmacologically active drug

Ex: skin permeation enhancers include non-ionic surfactants which cause changes in the

intracellular proteins of stratum corneum & increase permeability by this mechanism

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2. LIPOSOMAL DELIVERY SYSTEMS

Liposomes are composed of phospholipid bilayers capable of entrapping hydrophilic moieties

in the aqueous compartment & hydrophobic moieties in the lipid bilayers with cholesterol

imparting rigidity to the bilayer

Liposomal vaccines based on viral membrane proteins (virosomes) have been approved as

products in Europe for hepatitis A & influenza

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3. ORAL IMMUNIZATION

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Controlled release micro-particles for vaccine developmentPLGA (polylactide co-glycolic acid) is used as a biodegradable micro particle for vaccine

delivery due to the abundance of data & information on its properties, uses & role in on going

studies

Factors that effect the release pattern are:1. Molecular weight of compound- greater the mol. Wt. greater the bond, larger time to

degrade2. Chemical composition of co-polymer- release of the peptide was prolonged when

microspheres made of copolymer containing higher proportion of polylactide3. Size of the microspheres- greater the particle size longer the time to collapse, delays the

release of antigen

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Peptide based vaccinesA peptide vaccine is a type of subunit vaccine in which a peptide of the original pathogen is used to immunize an organism

These types of vaccines are usually rapidly degraded once injected into the body, unless they are bound to a carrier molecule such as a fusion protein

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Nucleic acid based vaccinesUse of nucleic acid-based vaccines is a novel approach to immunization that elicits immune

responses similar to those induced by live, attenuated vaccines

Nucleic acid vaccines have been shown to elicit both antibody and cytotoxic T-lymphocytes

responses to diverse protein antigens

ADVANTAGES:

Simplicity of the vector

The ease of delivery

Duration of expression

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DNA vaccinesDNA vaccination is a technique for protecting an organism against disease by injecting it with

genetically engineered DNA to produce an immunological response

These are the third generation vaccines & are made up of a small, circular piece of bacterial

DNA (called plasmid) that has been genetically engineered to produce one or two specific

proteins (antigens) from a pathogen

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RNA vaccines Recent studies have demonstrated that mRNA formulated in liposome's & administered

sub-cutaneously or intravenously, effectively generated antibody & act directed against the

encoded protein

However, the difficulty & expenses of large scale RNA production & the relative instability of

mRNA compared to DNA might render RNA vaccines an impractical means of immunization

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CONCLUSION The promise of peptides and proteins will lead to drug innovation and discovery, and

challenge the ingenuity of pharmaceutical developers to develop novel delivery methods for

present and future therapies

Although various vaccines have been successfully developed for several diseases, research is

still in progress to develop vaccines for life threatening diseases like cancer , AIDS etc

Novel vaccine delivery systems need to be developed in order reduce morbidity and mortality

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REFERENCES 1. Controlled drug delivery concepts and advances. By S.P.Vyas, Roop K. Khar, Vallabh

Prakashan, 1st edition, Page No: 503-70

2. Progress in controlled and novel drug delivery system, N. K. Jain, CBS publishers &

distributors, 1st edition, page no. 184-208

3. D. Sesardic and R. Dobblaer, European union regulatory developments for new vaccine

adjuvants and delivery systems, vaccine 22 (2004), pp. 2452-2456

4. Samantha Jilek, Hans P. Merkle, Elke Walker. “DNA- Loaded biodegradable microparticles

as vaccine delivery systems and their interaction with dendritic cells”, Page 378

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