Application of nanotechnology for the development of microbicides

Abstract

The vaginal route is increasingly being considered for both local and systemic delivery of drugs, especially those unsuitable for oral administration. One of the opportunities offered by this route but yet to be fully utilised is the administration of microbicides. Microbicides have an unprecedented potential for mitigating the global burden from HIV infection as heterosexual contact accounts for most of the new infections occurring in sub-Saharan Africa, the region with the highest prevalent rates. Decades of efforts and massive investment of resources into developing an ideal microbicide have resulted in disappointing outcomes, as attested by several clinical trials assessing the suitability of those formulated so far. The highly complex and multi-level biochemical interactions that must occur among the virus, host cells and the drug for transmission to be halted means that a less sophisticated approach to formulating a microbicide e.g. conventional gels, etc may have to give way for a different formulation approach. Nanotechnology has been identified to offer prospects for fabricating structures with high capability of disrupting HIV transmission. In this review, predominant challenges seen in microbicide development have been highlighted and possible ways of surmounting them suggested. Furthermore, formulations utilising some of these highly promising nanostructures such as liposomes, nanofibres and nanoparticles have been discussed. A perspective on how a tripartite collaboration among governments and their agencies, the pharmaceutical industry and academic scientists to facilitate the development of an ideal microbicide in a timely manner has also been briefly deliberated.

Utilizing Liposomal Quercetin and Gallic Acid in Localized Treatment of Vaginal Candida Infections

“…Among nanocarriers, liposomes are particularly suitable for vaginal delivery because they are not interfering with vaginal microbiota and are able to protect active substances against external enzymatic degradation and rapid perturbations that can occur in the vaginal cavity [22]. Moreover, they are biodegradable, biocompatible, weakly immunogenic and non-irritating to vaginal mucosa.…”

“…Despite the favorable pharmacological properties of polyphenols, their applicability remains limited by their low solubility and bioavailability as well as high susceptibility to environmental conditions, including biological environment. In this regard, the incorporation of polyphenols inside a nanocarrier can be an appropriate approach to avoid the degradation of active molecules and promote their deposition at the site of administration assuring enhanced biological effect [22][23][24].…”

The Vaginal-PVPA: A Vaginal Mucosa-Mimicking In Vitro Permeation Tool for Evaluation of Mucoadhesive Formulations

“…The use of liposomes as drug-delivery systems for vaginal administration has gained increasing attention over the past decades [17,[23][24][25] due to their biodegradability, biocompatibility, non-irritating properties towards the vaginal mucosa and to their intrinsic capacity of shielding active substances from the possible degradation occurring at the vaginal site [26]. Moreover, the coating of these formulations with chitosan can improve the mucoadhesive and antimicrobial properties of such drug-delivery systems [6,13,17], which enables higher resident time in the vagina and aids against bacterial infections.…”

Pharmaceutical Vehicles for Vaginal and Rectal Administration of Anti-HIV Microbicide Nanosystems

“…More than a trendy gimmick, the application of nanotechnology to the development of anti-HIV microbicides relies on solid research work, as previously revised by our group [7,36] and others [37,38]. General advantageous features are schematically presented in Figure 1.…”