Polymeric Nano/Microparticles for Oral Delivery of Proteins and Peptides - Biomaterials Fabrication and Processing - page 171

7 Polymeric Nano/Microparticles

for Oral Delivery of Proteins
and Peptides

Sajeesh S. and Chandra P. Sharma

CONTENTS

7.1 Introduction........................................................................................................................... 171
7.2 Barriers to Oral Delivery of Proteins/Peptides..................................................................... 172
7.3 Strategy for Improved Oral Protein Delivery ....................................................................... 173
7.4 Polymeric Nano/Microparticles as a Possible Oral
Peptide-Delivery System....................................................................................................... 173
7.4.1 Synthetic Biodegradable Polymeric Nano/Microparticles ........................................ 175
7.4.2 Nonbiodegradable Synthetic Polymers...................................................................... 179
7.4.3 Natural and Protein-Based Polymers for Oral Peptide Delivery .............................. 182
7.4.3.1 Protein-Based Polymers for Oral Protein Delivery .................................... 183
7.4.4 Preparation of Nano/Microparticles.......................................................................... 183
7.4.4.1 Nano/Microparticles Obtained by Polymerization
of Monomers ............................................................................................... 184
7.4.4.2 Particles from Preformed Polymers ............................................................ 186
7.5 Concluding Remarks............................................................................................................. 187
References ...................................................................................................................................... 187

7.1 I N T R O D U C T I O N
Recent advancement in the fi eld of pharmaceutical biotechnology and introduction of recombinant
DNA technology have led to the production of a number of therapeutic peptides and proteins for the
treatment of several life-threatening diseases (Table 7.1). A number of peptide-based therapeutics
such as recombinant hormones, cytokines, vaccines, monoclonal antibodies, therapeutic enzymes,
and the like have been recently approved for clinical use [1]. However, most of these peptides are
administrated by parenteral route. Inherent short half-lives of peptides and chronic therapy require-
ments in a majority of cases make their repetitive dosing necessary [2]. Frequent injections, oscil-
lating blood drug concentrations, and low patient acceptability make even the simple parenteral
administration of these drugs problematic [3,4]. In spite of signifi cant advancement in the fi eld of
pharmaceutical research, development of a proper noninvasive delivery system for peptides remains
a distant reality. Although there have been reports of successful delivery of various peptide thera-
peutics across nonoral mucosal routes (such as nasal and buccal), the oral route continues to be the
most preferred route for drug administration [5-7]. The oral route, despite enormous barriers that
exist in the gastrointestinal tract (GIT), has obvious advantages such as ease of administration,
patient compliance, and cost effectiveness [8,9].

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