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Strategies for oral delivery of proteins and peptides

Presented by:-Mr. Mane Avinash A.M.Pharm sem.-ÍÍDept. of Pharmaceutics

Guided by:-Mr. Galgatte U.C.Associate Professor Dept. of Pharmaceutics

P. E. SOCIETY’S MODERN COLLEGE OF PHARMACY NIGDI,PUNE,44

2015-16

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Peptides are short polymers formed from the linking, in a defined order, of α-amino acids. The link between one amino acid residue and the next is known as an amide bond or a peptide bond.

INTRODUCTION

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Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues

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Primary structure- The amino acid sequence.

Secondary structure- Regularly repeating local structures

stabilized by hydrogen bond.

Tertiary structure- The three dimensional structure of the

polypeptide.

Quaternary structure-The structure formed by 2 or more

polypeptide chains associated by non covalent forces.

STRUCTURE OF PROTEIN

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1. Erythropoietin used for production of RBC.

2. Tissue plasminogen activator is used for Heart attack, Stroke.

3. Oxytocin maintain labor pain.

4. Bradykinin increases the peripheral circulation.

5. Somatostatin decrease bleeding in gastric ulcer.

6. Gonadotropin induce ovulation.

7. Insulin maintain blood sugar level.

ADVANTAGES

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1. Transport and storage of small molecules.

2. Coordinated motion via muscle contraction.

3. Mechanical support from fibrous protein.

4. Generation and transmission of nerve impulses.

5. Enzymatic catalysis.

6. Immune protection through antibodies.

7. Control of growth and differentiation via hormones.

FUNCTIONS

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1. Elimination by B and T cells.2. Proteolysis by endo/exo peptidases.3. Small proteins filtered out by the kidneys very

quickly.4. Unwanted allergic reactions may develop (even

toxicity).5. Loss due to insolubility/adsorption.

PROBLEMS WITH PROTEINS(in vivo – in the body)

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Encapsulated peptides or proteins in amino acids with microspheres of approximately 10 micron in diameter , used for oral delivery.

Example: Insulin and heparin.Orally administered insulin produces hypoglycemic

effect .

ORAL ROUTE

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The ease of administration and higher degree of patient compliance with oral dosage forms are the major reasons for preferring to deliver proteins and peptides by mouth.

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protection  against  the  metabolic  barrier  in  GIT absence of a carrier system  for  absorption of 

peptides with more than three amino acids Proteins  are labile  due  to  susceptibility  of  the 

peptide  backbone  to  proteolytic  cleavage Prodrug approach

olefenic  substitution,  d‐amino  acid  substitution, dehydro  amino  acid  substitution, carboxyl  reduction

Problems associated with oral delivery

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1. Amino acid modifications Metkephamid, an analog of methionine

encephalin with substitution of glycine by l-alanine ₂and modified methionine, readily penetrated across the nasal mucosa with 54% bioavailability relative to subcutaneous administration but was orally inactive

Maximising oral protein and peptide absorption

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2. Hydrophobization Hydrophobization of peptides may be attempted by two

approaches. The first is peptide backbone modification to include more of hydrophobic amino acids; the second would be covalent conjugation of a hydrophobic moiety—for example, a lipid or polymeric tail.

Increasing the hydrophobicity of a peptide or protein by surface modification using lipophilic moieties may be of particular benefit to trans cellular passive or active absorption by membrane penetration or attachment, respectively; or it may simply aid in the increased stability of the protein.

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EXAMPLE lipophilic modification of TRH by covalent

conjugation of lauric acid to this tripeptide (Lau-TRH). The derivative was more stable in rat plasma and was rapidly converted to TRH in the intestinal mucosal homogenate.

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Formulating for delivery through the gastrointestinal (GI) tract requires a multitude of strategies

To alter the environment for maximum solubility and enzyme stability of protein by using formulation excipients such as buffers surfactants and protease inhibitors

To promote absorption through the intestinal epithelium

Strategies for oral delivery

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Barriers to the absorption of drug in the intestine

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Bonding of (PEG) and alkyl groups fatty acid  radicals to produce desired amphiphilic oligomers oligomers are conjugated to proteins or peptides to  obtain desired amphiphilic products can resist excessive degradation  of  protein or

peptide drugs technology reduces self‐

association, increases penetration  and increases  compatibility  with  formulation ingredients than parent drug

Nobex technology

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Nobex conjugation technology

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Oral delivery is the most sought after route of administration for most of the drugs and pharmaceutical products, which depends on the drug’s molecular structure or weight

Transport mechanism of macromolecules

Peroral route: promises and pitfalls

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(A) Transport mechanism of bio drug through the intestinal epithelium membrane,

(B) Probable mechanism of penetration enhancer,

C) enzyme inhibitors, (D) Representative mechanism of prodrug

absorption and its activation.

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1. Enzyme inhibitors (protease inhibitors)2. Absorption enhancers (permeation

enhancers)3. Mucoadhesive polymeric systems4. Novel carrier systems5. Prodrug strategies

Formulation approaches for oral delivery of proteins and peptides

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Sr.no.

Approach Examples Effects on bioavailability

Drawbacks

1 Absorption enhancers

Bile salts, fatty acids, Surfactants (anionic, cationic)

Enhanced bioavailability by increased membranepermeation

Available transport systems of both proteins/peptides and undesirable molecules in GIT

2 Enzyme inhibitors

Sodium glycocholate, camostate mesilate

Resisted enzymes degradation in stomach and intestines

Produced severe side effects in the treatment of chronic diseases such as diabetes, etc.

3 Mucoadhesive polymeric systems

Thiolated polymer

Site–specific delivery and improved membrane permeation

Limitation due to the mucus turnover in absorption sites (intestine)

4 Prodrug strategies

Phenyl propionic acid

Prodrug permeabilityimproved 1608fold than parent drug

Lack of methodology, structuralcomplexity, stability problem of protein

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Desmopressin acetate (DDAVP) is a synthetic analogue of 8 arginine vasopressin: ant diuretic hormone. Marketed by Aventis pharmaceutical and is approved for diabetes insipidus.0.16 % bioavailable

Novartis and Roche pharmaceutical market cyclosporine (small lyophilic mol. For graft rej.) 30% bioavailability

Oral peptides today(Application)

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Aim: Design and In Vitro Characterization of

Buccoadhesive Drug Delivery System of Insulin

Preparation Method: A buccoadhesive drug delivery system of

Insulin was prepared by solvent casting technique and characterized in vitro by surface pH, bio adhesive strength, drug release and skin permeation studies. Sodium carboxymethyl cellulose-DVP was chosen as the controlled release matrix polymer.

Case Study

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Result: it is concluded that the system is a

success as compared to the conventional formulations with respect to invasiveness, requirement of trained persons for administration and most importantly, the first pass metabolism.

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Company Product name

Formulation

Development phase

Product

Apollo Life Science

Oradell Tablet Clinical phase I b

Insulin, TNF-blocker

Emisphere Eligen Tablet Phase II Calcitonin, insulin, PTH, heparin

Nobex/Biocon

HIM2 Liquid Abandoned Insulin, enkephalin, calcitonin

Technologies for oral delivery of proteins under clinical development by companies.

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Company Product name

Formulation

Development phase

Product

Oramed ORMD-0801ORMD-0901

Capsule Phase I Insulin/Exenatide

Diasome pharmaceuticals

Hepatic-directedvesicles-insulin(HDV-1)

Tablet Phase II/III Insulin

Diabetology Capsulin Capsule Phase II Insulin

Merrion pharma (Ireland)with Novo-Nordisk

Vetsulin Matrix tablet Phase I Insulin and GLP-1 analogues

Chiasma (Israel)

Octreolin Suspension Phase I (phase I completed,phase III enrolling

Octreotide

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NAME OF PUBLICATI

ON

PUBLICATION NO.

TYPE DATE INVENTOR

Oral delivery of modified

transferrin fusion

proteins

US8129504 B2

Grant 6 march 2012

Christopher p.Prior ,

Homoyoun sodeghi,Andrew turner.

Peptide library and screening systems

US5432018 A

Grant Jul 11, 1995 William J. Dower, Steren

E.cwirla, Ronald

W.barrettPeptide

conjugateUS5442043 Grant Aug 15,1995 Takeda

chemical industries

PETENTS

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1. McNally Ej. protein formulation and delivery. In: Drug and the pharmaceutical sciences.2nd ed. New York: Marcel Dekker; 2000.p.99-125

2. Novel drug delivery system by Dr. D. K. Jain and Dr. D. T. Baviskar Nirali prakashan Page no.14.1-14.7

3. Agarwal, V., Khan, M.A., 2001. Current status of the oral delivery of insulin. Pharm. Tech. 25 (10), 76–90.

4. Antunes, F., Andrade, F., Ferreira, D., Morck, N.H., Sarmento, B., 2013. Models to predict intestinal absorption of therapeutic peptides and proteins. Curr. Drug Metab. 14 (1), 4–20.

5. Aoki, Y., Morishita, M., Asai, K., Akikusa, B., Hosoda, S., Takayama, K., 2005. Region dependent role of the mucous/ glycocalyx layers in insulin permeation across rat small intestinal membrane. Pharm. Res. 22 (11), 1854–1862.

References

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