Emerging potential of niosomes in ocular delivery

ABSTRACT

Introduction

Niosomes have recently grabbed attention as one of the best tools for various site-specific drug delivery systems, including ophthalmic drug delivery. Surfactants (nonionic; tweens and spans) of different HLB values and cholesterol are the fundamental components for these formulations. It is an alternative controlled ocular drug delivery system to liposomes to overcome the problems associated with sterilization, large-scale production, and stability. It also enhances the adhesion or retention ability of drug at the ocular site. Hydrophilic or lipophilic or amphoteric drugs can be easily encapsulated in niosomes. Besides, niosomes are a leading vesicular system compatible with most of the drugs for site-specific delivery.

Areas covered

This article reveals challenges and barriers for ocular drug delivery, various transporters and receptors present in the ocular region for the transportation of therapeutics as well as nutrients, and various method of preparations, loading methods and application potential of niosomes in ocular drug delivery.

Expert opinion

Niosomes, a vesicular system offers numerous advantages and applicability because of its good stability, non-immunogenicity, permeation potential, and controlled release ability etc. This drug delivery system has been efficiently used in the treatment of many ocular diseases.

KEYWORDS:

• Niosomes
• ocular
• drug delivery
• surfactant
• cholesterol
• vesicular system

Article highlights

• Niosomes are stable, compatible, and less toxic drug delivery systems and are composed of biodegradable materials with mainly non-ionic surfactants.

• These drug delivery systems have promising potential for the treatment of various ocular diseases.

• Major techniques exploited in the preparation of niosomes are thin layer evaporation, reverse phase evaporation, solvent injection, and proniosome method.

• Hurdlesome barriers in ocular drug delivery include barriers of anterior segments, and posterior segments, and protective barriers.

• Several transporters like peptide transporters, glucose, vitamin C transporters, amino acid transporters, and efflux transporters, and glucose transporters are present in ocular region.

• P-glycoprotein mediated efflux pump inhibitors and mucoadhesive polymers-based novel nanocarriers are being used to enhance the ocular bioavailability.

• Niosomes based drug delivery systems improve the ocular bioavailability, increase the drug retention time, and enhance the permeation of drug across cornea.

This box summarizes key points contained in the article.

Declaration of interest

A Verma is thankful to Indian Council of Medical Research, New Delhi for rendering Research Associateship (RA). A Tiwari, S Saraf and PK Panda are thankful to Indian Council of Medical Research, New Delhi for rendering Senior Research Fellowship (SRF). 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.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.