Buccal iontophoresis: an opportunity for drug delivery and metabolite monitoring

doi:10.1016/j.drudis.2011.01.012

Drug Discovery Today

Volume 16, Issues 7–8, April 2011, Pages 361-366

https://doi.org/10.1016/j.drudis.2011.01.012 Get rights and content

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Electrical enhancement of drug delivery

The physiological function of human skin or oral mucosa is not to absorb any substance, but rather to prevent this to protect homeostasis. To make drug delivery possible via this route, various chemical drug absorption enhancers or physical methods are used (e.g. electric field, microneedles and sonophoresis). The application of an electric field is particularly beneficial as it can impose an additional driving force on drug ions (iontophoresis), force water (or bodily fluids) to flow with the

Buccal route

The buccal mucosa is an attractive area for electrical drug delivery. It easily withstands long-term permanent wetting and regenerates quickly. It is not as resistive to damage compared with skin, but is generally more permeable [18]. The oral cavity mucosa is convenient for drug delivery and offers the possibility for the application of many types of drug delivery system. Orotransmucosal varieties of drug delivery systems are popular and available in various forms, including solid and

From drug delivery enhancement to a feedback loop system

The number of publications describing electrical transbuccal drug delivery is limited, with the main tissue models being porcine buccal mucosa (which closely resembles human mucosa [29]) and reconstituted human oral epithelium (cell culture TR146) [30]. Porcine buccal mucosa was used in the in vitro experiments described in 31, 32, 33, 34, whereas in vivo experiments using domestic pig are described in 35, 36; by contrast, reconstructed human epithelium was used a model in [37]. The model drugs

Numerical simulations of electrically enhanced drug transport

The discussion above focuses on the ideal drug transport process in the form of an electric field. However, such a situation is not always possible as it is difficult to place counter electrodes outside the cheek. The IntelliDrug implant assumes the form of a coaxial rings electrode that enables the whole device to be located inside the oral cavity. This differs from the usual geometry applied by researchers during in vitro experiments. How this system will work? Will it be efficient? Numerical

Reverse iontophoresis

As mentioned above, the transfer of cations through skin or mucosa is preferential and induces a net movement of body fluids. This phenomenon (iontophoresis) can be used in the sampling of body fluids to measure the concentration of certain metabolites, such as glucose [44]. Taking into account the recent development of microsensors, it is possible to design a miniature, mobile system for body condition and metabolite concentration monitoring. Several clinical sensors are already available, for

Perspectives

In this review, we have described the properties of buccal mucosa as a target for electrically enhanced drug delivery. We have also shown that the same area can serve as a site for body fluids sampling by reverse iontophoresis. The combination of drug delivery and metabolite sampling in one device, and the use of the same driving force, is very promising. Such a device can sample body fluids and detect metabolite concentration with a proper sensor placed behind the sampling membrane. Placing a