Recent advances in oral delivery of peptide hormones

ABSTRACT

Introduction: Oral delivery of therapeutic peptide hormones offers the promise of greater patient compliance when compared to parenteral administration routes. However, it is a huge challenge in the pharmaceutical field. Due to increasing demand for oral delivery of peptide hormones such as insulin, gonadotropin-releasing hormones, and calcitonin, various technologies have been explored to overcome the associated hurdles.

Areas covered: This review article summarizes the physiological barriers to the oral delivery of peptide hormones and some of the key strategies to circumvent these barriers and enhance peptide hormones’ oral bioavailability. In addition, recent advances in oral formulation strategies of peptide hormones, under development and within the clinical trial stages, are discussed.

Expert Opinion: The pharmaceutical industry has devoted much effort to develop new, and often complex peptide hormone products based on formulation strategy. Use of the native structure of the peptide hormones in oral formulations could result in an unpredictable pharmacokinetic profile. Authors believe that considering chemical modification prior to formulation is essential to achieve orally active products.

Although no major breakthrough has been achieved for effective oral delivery of peptides hormones yet, the substantial efforts by industrial and academic laboratories might yield successful results in near future.

KEYWORDS:

• chemical modification
• clinical trial
• formulation
• metabolic stability
• oral bioavailability
• oral delivery
• peptide hormones
• permeability

Article highlights

• This review discusses physiological barriers in the gastrointestinal tract, which impedes the oral absorption of peptide hormones.

• Several approaches have been established to overcome the existing barriers for the oral delivery of peptide hormones and are broadly categorized into chemical and physical strategies.

• Present strategies attempt to provide structural protection of the peptide hormones.

• Various oral formulations are under development and within the clinical trial stages.

• Thus far, few chemically modified peptide hormones with significant oral bioavailability have reached the pharmaceutical market.

This box summarizes key points contained in the article.

Declaration of interest

The authors would like to acknowledge the Australian Research Council for their support of this work with the Discovery Project Grant and Professorial Research Fellowship to I Toth (DP110100212). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed