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Protein Pharmaceuticals (VI) “Formulation and Delivery” Dr. Aws Alshamsan Department of Pharmaceutics Office: AA87 Tel: 4677363 [email protected] Objectives of the Lecture By the end of this lecture you will be able to: 1. Describe techniques for optimal protein formulation 2. Realize the importance of delivery systems for protein pharmaceuticals 3. Compare different delivery methods Solving the problems Microbial Considerations Additives Storage Formulation Delivery Solving the problems Microbial Considerations Additives Storage Formulation Delivery Formulation • Biotechnology products are generally sensitve and have considerably short as compared to lowmolecular weight drugs. • Optimal formulation is supposed to improve the product stability in vitro and in vivo. Site-Directed Mutagenesis • Bioengineering process that creates a mutation as a defined site in the DNA strand. • Engineered proteins can be tailored for a specific application or improved stability. Site-Directed Mutagenesis Site-Directed Mutagenesis PEGylation • Covalent attachment of PEG to another molecule such as protein. PEGylation • Significantly increases in vivo half life • Prevents from proteolytic enzymes degradation Increase in size to reduce kidney filtration PEG Protein Decrease accessibility for proteolytic enzymes and antibodies PEGylated proteins in the market Brand Name Drug name Parent Drug Indication Approval Year 1990 Adagen® Pegadamase Adenosine deaminase Severe combined immunodeficiency disease (SCID) Oncaspar® Pegaspargase Asparaginase Leukaemia 1994 PEG-INTRON® Peginterferon-a2b IFN-a2B Hepatitis C 2000 PEGASYS® Peginterferon-a2a IFN-a2A Hepatitis C 2001 Neutropenia 2002 Acromegaly 2003 Neulasta® Pegfilgrastim Somavert® Pegvisomant Macugen® Mircera® Cimzia® Granulocyte-colony stimulating factor (GCSF) Growth Hormone antagonist Age-related macular degeneration Epoetin beta-methoxy Anemia associate with Erythropoietin (EPO) polyethylene glycol Kidney disease PEG-Certolizumab Rheumatoid arthritis Anti-TNF Fab pegol & Crohn’s disease Pegaptanib Anti-VEGFc aptamer 2004 2007 2008 Peptide Micelles Hydrophilic block Hydrophobic block Peptide O H H3N+ H R1 N H R2 H N O H PEG O H R3 N H R4 O O CH-CH-CH-CH-CH-CH-CH-CH-CH-CH | | | | | | | | | | OH OH OH OH OH OH OH OH OH OH Solving the problems Microbial Considerations Additives Storage Formulation Delivery Targeted Micelles Liposomes • Phospholipid bilayer • Aqueous core • 80-100nm in size • Biocompatible • Uni- or Multilamellar • Could be easily functionalized Liposomes • Preferential retention in leaky vasculature e.g. cancer • Easily uptaken by macrophages • Overcome by Stealth property (PEGylation) Liposomes Liposomes Microspheres and Nanoparticles • Encapsulation of a protein or peptide inside a porous particle • Constructed of Biodegradable, Biocompatible polymer – PLGA (FDA approved) Microspheres and Nanoparticles Microspheres and Nanoparticles Polymeric Nanoparticle Uptake by Human DCs: SEM image Polymeric Nanoparticle Uptake by Human DCs: Confocal Image Protein Delivery • Drugs could be administered by several routs: – Parenteral (injections) – Transdermal – Oral Parenteral Parenteral Delivery • • • • • • • • Route of delivery for 95% of proteins Allows rapid and complete absorption Allows smaller dose size (less waste) Avoids first pass metabolism Avoids protein “unfriendly zones” Problems with overdosing, necrosis Local tissue reactions/hypersensitivity Everyone hates getting a needle Oral (GI-MAPS®) Transdermal Patches • Proteins imbedded in a simple matrix with appropriate additives • Patch is coated with small needles that penetrate the dermal layer • Proteins diffuse directly into the blood stream via capillaries • Less painful form of parenteral drug delivery Transdermal patch Small Pins Skin Close-up of Patch Pins Exubera (Inhaled Insulin) • Exubera, a dry-powder form of insulin, is inhaled with a special device similar to an asthma inhaler • Exubera normalized blood sugar levels as well as injections did • Patients taking inhaled insulin also reported greater satisfaction and quality of life (for 18+ only) • About 1/5 study subjects developed a mild cough with inhaled insulin • Product pulled in Oct. 2007 Pfizer Oral (Oralin/Oral-Lyn) by GENEREX It is not oral, it is buccal Oral Insulin (Oralin/Oral-lyn) • Bucchal aerosol delivery system developed by Generex (Approved in Ecaudor and India) Oral Insulin (Oralin/Oral-lyn) • Insulin is absorbed through thin tissue layers in mouth and throat • Insulin is formulated with a variety of additives and stabilizers to prevent denaturation on aerosolization and to stabilize aerosol particles Oral insulin by NOBEX • Conjugate the lysine residue with amphiphilic oligomer • Alkyl chain + PEG • Enhance stability in vivo • Hydrolysis of oligomer release the native structure • Phase II clinical trial (2004) Future Delivery Future Delivery (Biocapsule) • Encapsulation of insulinsecreting cells (insulinoma) • Immune components physically excluded • Glucose molecules pass freely • Insulin is secreted in response to glucose Biocapsules Protein Pharmaceuticals Now you are able to: Describe techniques for optimal protein formulation Realize the importance of delivery systems for protein pharmaceuticals Compare different delivery methods Next Lecture • Biotechnology-based vaccines