Actinic keratosis and imiquimod: a review of novel carriers and patents

ABSTRACT

Introduction: Actinic keratosis is one of the most common disorder characterized by erythematic and generally attached scaly lesions which are present either alone or in clusters. World Health Organization defines actinic keratosis as a common intraepidermal neoplasm of sun-damaged skin, characterized by variable atypia of keratinocytes.

Area covered: At the beginning of the 20th century, a new immunomodulator molecule, imiquimod, appears in the market for the treatment of actinic keratosis but suffers from the pitfalls of the conventional approach of dosage form preparation including high dose, poor stability and more side effects. The present article attempts to compile the scatter information related to actinic keratosis and imiquimod at one place. The special emphasis will be made on the information available in various research articles and patents with respect to the efforts made for overcoming shortcomings associated with imiquimod by novel drug delivery or other approaches.

Expert opinion: The conventional drug delivery systems are unsuccessful to improve the actinic keratosis. The patient acceptance and compliance with these treatments are generally poor due to associated side effects, poor cosmetic outcomes and high costs. Therefore, several available and reported novel therapeutic approaches are being developed in order to provide better action.

KEYWORDS:

• Actinic keratosis
• imiquimod
• immunomodulator
• vesicles
• nanoparticles

Article highlights

• The article provides preliminary information on prevalence, pathogenesis and clinical symptoms of actinic keratosis.

• Comparison of available therapeutic modalities in terms of efficacy, cosmetic outcomes and cost.

• Imiquimod and novel carriers or strategies employed to improve its physicochemical properties, delivery, safety, and efficacy

• Patents granted, expired, filled and withdrawn relating to imiquimod delivery, safety,  and therapeutic application, especially in India.

• Conventional drug delivery systems are unsuccessful to improve the actinic keratosis.

This box summarizes key points contained in the article.

Declaration of interest

The authors have no 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. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

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

Additional information

Funding

This paper was not funded.