Therapeutic applications of hydrogels in oral drug delivery.
BACKGROUND
Oral delivery of therapeutics, particularly protein-based pharmaceutics, is of great interest for safe and controlled drug delivery for patients. Hydrogels offer excellent potential as oral therapeutic systems due to inherent biocompatibility, diversity of both natural and synthetic material options and tunable properties. In particular, stimuli-responsive hydrogels exploit physiological changes along the intestinal tract to achieve site-specific, controlled release of protein, peptide and chemotherapeutic molecules for both local and systemic treatment applications.


METHODS
This review provides a wide perspective on the therapeutic use of hydrogels in oral delivery systems. General features and advantages of hydrogels are addressed, with more considerable focus on stimuli-responsive systems that respond to pH or enzymatic changes in the gastrointestinal environment to achieve controlled drug release. Specific examples of therapeutics are given. Last, in vitro and in vivo methods to evaluate hydrogel performance are discussed.


CONCLUSIONS
Hydrogels are excellent candidates for oral drug delivery, due to the number of adaptable parameters that enable controlled delivery of diverse therapeutic molecules. However, further work is required to more accurately simulate physiological conditions and enhance performance, which is important to achieve improved bioavailability and increase commercial interest.
The University of Texas, Department of Biomedical Engineering , Austin, TX 78712 , USA +1 512 471 6644 ; +1 512 471 8227 ; peppas@che.utexas.edu .
Lindsey A
LA
Sharpe
Adam M
AM
Daily
Sarena D
SD
Horava
Nicholas A
NA
Peppas
D000284:Administration, Oral; D000818:Animals; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D020100:Hydrogels / Q000008:administration & dosage* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010455:Peptides / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000008:administration & dosage* / Q000737:chemistry; D011506:Proteins / Q000737:chemistry
D003692:Delayed-Action Preparations; D020100:Hydrogels; D010455:Peptides; D004364:Pharmaceutical Preparations; D011506:Proteins
controlled release; drug delivery; hydrogel; intelligent system; oral delivery