Carlo Paderni

Efficacy and Safety of an Intraoral Electrostimulation Device for Xerostomia Relief: A Multicenter, Randomized Trial

OBJECTIVE To evaluate the efficacy and safety of an intraoral electrostimulation device, consisting of stimulating electrodes, an electronic circuit, and a power source, in treating xerostomia. The device delivers electrostimulation through the oral mucosa to the lingual nerve in order to enhance the salivary reflex. METHODS The device was tested on a sample of patients with xerostomia due to Sjögrens syndrome and other sicca conditions in a 2-stage prospective, randomized, multicenter trial. Stage I was a double-blind, crossover stage designed to compare the effects of the electrically active device with the sham device, each used for 1 month, and stage II was a 3-month open-label stage designed to assess the long-term effects of the active device. Improvement in xerostomia severity from baseline was the primary outcome measure. RESULTS A total of 114 patients were randomized. In stage I, the active device performed better than the sham device for patient-reported xerostomia severity (P<0.002), xerostomia frequency (P<0.05), quality of life impairment (P<0.01), and swallowing difficulty (P<0.02). At the end of stage II, statistically significant improvements were verified for patient-reported xerostomia severity (P<0.0001), xerostomia frequency (P<0.0001), oral discomfort (P<0.001), speech difficulty (P<0.02), sleeping difficulty (P<0.001), and resting salivary flow rate (P<0.01). CONCLUSION Our findings indicate that daily use of the device alleviated oral dryness, discomfort, and some complications of xerostomia, such as speech and sleeping difficulties, and increased salivary output. The results show a cumulative positive effect of the device over the period of the study, from baseline to the end of the trial.

Oral local drug delivery and new perspectives in oral drug formulation.

Modern pharmaceutical science has provided us with a wide range of substances to be administered with a wide large variety of dosage forms. Local drug delivery systems have been used for a long time; in particular, for the local therapy of diseases affecting the oral cavity. Although these diseases are often extremely responsive to local therapy, the mouth often presents various difficulties in the application of topical compounds (owing to saliva and the mouths different functions), resulting in a short retention time of dosage forms with a consequent low therapeutic efficacy. To resolve these limitations, research today concentrates on the development of bioadhesive formulations. This review focuses on the permeability features of oral mucosa, the rationale of oral local drug delivery, and new potential bioadhesive local delivery systems. Furthermore, the most promising mucoadhesive systems proposed to locally treat oral diseases are discussed.

Human Buccal Mucosa as an Innovative Site of Drug Delivery

The authors review the ultra-structural aspects and permeability features of normal human oral mucosa, after having recently tested and used it as a new site of systemic drug delivery. The pertinent scientific literature from 1975 through 2009 has been analysed and discussed. Buccal epithelium is a relatively permeable, robust non-keratinized tissue and blood vessels drain directly into the jugular vein; due to its particular features, it has been of increasing interest to researchers as an alternative site of drug administration. The review describes the structure and function of the buccal mucosa, the rationale for transbuccal drug delivery and the main transmucosal drug delivery systems. Recent studies have investigated the delivery of a variety of drugs through the buccal mucosa in order to assess both local and systemic, either positive or adverse, effects. In conclusion, buccal mucosa may be considered a promising site for effective, safe and non-invasive transmucosal sustained drug delivery.

Bioavailability in vivo of naltrexone following transbuccal administration by an electronically-controlled intraoral device: A trial on pigs

Naltrexone (NLX), an opioid antagonist, is widely used in the treatment of opiate addiction, alcoholism and smoking cessation. Its current peroral administration induces various adverse side effects and has limited efficacy since bioavailability and patient compliance are poor. The development of a long-acting drug delivery system of NLX may overcome the current drawbacks and help in the improvement of treatment of addiction. The primary endpoints of this study were: a) to compare the NLX bioavailability and pharmacokinetics after delivering a single transbuccal dose, released by a prototype of intraoral device, versus an intravenous (I.V.) bolus of the same drug dose; b) to verify the functioning of a prototype of a new intraoral device in vivo; c) to evaluate the permeation enhancement effect of iontophoresis; d) to assess any histomorphological changes in the buccal mucosa after transbuccal delivery. The system was tested on 6 pigs in a cross-over trial. Venous blood samples were drawn at a fixed timetable from the beginning of drug administration and analyzed for the presence of NLX, using an LC/MS/MS method. A punch biopsy was performed for histological analysis after the final experiment. The administration of I.V. NLX induced a sharp increase in blood levels after 5 min and then a steep decrease. In contrast, transmucosal delivery resulted in a gradual increase in blood NLX levels, reaching its peak after 90 min, followed by a slow decrease. After 6h the blood levels of NLX delivered through the buccal mucosa were higher as compared to I.V. administration. No signs of flogosis or tissue damage were histologically highlighted. These results suggest that buccal delivery by an intraoral electronic device could potentially induce long-lasting, continuous and controlled blood levels of NLX, avoiding at the same time spikes of drug plasma levels typical of the I.V. administration route.

Intraoral electrostimulator for xerostomia relief: a long-term, multicenter, open-label, uncontrolled, clinical trial

OBJECTIVE A previous sham-controlled multinational study demonstrated the short-term efficacy and safety for xerostomia treatment of an intraoral device that delivers electrostimulation to the lingual nerve. The objective of this study was to test the hypothesis that those beneficial effects would be sustained over an 11-month period. STUDY DESIGN The device was tested on a mixed sample of 94 patients with xerostomia in an open-label, uncontrolled, prospective multicenter trial. Statutory outcome assessments were done at 5th, 8th, and 11th months and analyzed by multiple comparisons. RESULTS Improvements achieved at month 5 from baseline were sustained throughout the follow-up period for the primary outcome, xerostomia severity, and the secondary outcomes resting whole salivary flow rate, xerostomia frequency, oral discomfort, and difficulties in speech, swallowing, and sleeping. No significant side effects were detected. CONCLUSIONS The beneficial effects of a removable intraoral electrostimulating device were sustained for an 11-month period.

Evaluation of galantamine transbuccal absorption by reconstituted human oral epithelium and porcine tissue as buccal mucosa models: part I.

Over the last decade, interest in delivering drugs through buccal mucosa has increased. As a major limitation in buccal drug delivery could be the low permeability of the epithelium, the aim of this study was to evaluate the aptitude of galantamine, useful in Alzheimers disease, to penetrate the buccal mucosa. The evaluation of the ability of galantamine to permeate through the buccal epithelium was investigated using two permeation models. Firstly, in vitro permeation experiments were carried out using reconstituted human oral non-keratinised epithelium and Transwell diffusion cells system. Results were validated by ex vivo experiments using porcine buccal mucosa as membrane and Franz type diffusion cells as permeation model. The entity of buccal permeation was expressed in terms of drug flux (J(s)) and permeability coefficients (K(p)). Data collected by in vitro and ex vivo experiments were in agreement and suggested that buccal mucosa does not block diffusion of galantamine. The effects of drug application on histology of tissue specimens used in every experiment were also studied: no sign of flogosis and no significant cytological or architectural changes were highlighted.

Mucoadhesive Polymers for Oral Transmucosal Drug Delivery: A Review

The oral mucosa offers an interesting site for the application of dosage forms that release drugs within/throughout the oral mucosa, by assuring a high drug bioavailability for topic and systemic effects. However, the relative permeability of the oral mucosa and the washing effect related to the oral fluids and mechanical stresses must be considered in the formulation of oral dosage forms. Since a sustained drug release can be guaranteed only if dosage forms remain in contact with the oral site of absorption/application for a prolonged time, the development of mucoadhesive dosage forms is mandatory. The mucoadhesion is a complex phenomenon and the mucoadhesive bond consists of two different parts, the mucoadhesive polymers and the mucous substrate. In addition to factors related to the oral mucosa and oral environment features, the physical-chemical characteristics of mucoadhesive polymers must be also considered as factors influencing the mucoadhesive bonds. While it is not possible to modify the mucosal features or it is possible to modify or inhibit only in part certain mucosal processes, the knowledge of polymer properties influencing mucoadhesive bonds allows to modify or to control these properties in developing increasingly effective mucoadhesive systems. The aims of this review are to discuss the several mechanisms and factors behind the phenomenon of mucoadhesion with particular reference to the features of the oral environment, oral mucosa, and polymeric compounds influencing mucoadhesion process. Finally, a brief mention to the main mucoadhesive dosage forms designed for oral transmucosal drug delivery is made.

Topical therapies for oral lichen planus management and their efficacy: a narrative review.

Oral Lichen Planus (OLP) is a chronic inflammatory condition implicating T cell-mediated cytotoxicity, and involving oral mucosal surfaces. Several therapeutic regimens have been evaluated to treat OLP and pain related, but often without high level of evidence. Topical formulations are the favourite for the majority of cases; bioadhesive formulations have been considered very useful and practical for local drug delivery in oral mucosa, due to the increased residence time on the oral mucosa of the dosage forms and better therapeutic efficacy. In this narrative review, authors try to illustrate the current topical managements for OLP from the accessible literature on this topic. Steroids are very helpful in discomfort and making better quality of life: they are considered the first-line treatment even if they could cause secondary candidosis, and sometimes bad taste, nausea, dry mouth, sore throat or swollen mouth. Other substances or devices by topical administration are adopted especially when the first line approach is refractory. This is the case when retinol with its synthetic and natural analogues (retinoids), hyaluronic acid, or Aloe Vera are chosen. Recent topical applications for OLP therapy include phototherapy and low/high energy pulsing light; the treatment with extracorporeal photochemotherapy is also reasonable and promising. Finally, calcineurin inhibitors (i.e. cyclosporine, tacrolimus and pimecrolimus), antioxidant and biologics (i.e alefacept, efalizumab, basiliximab, TNF-α inhibitors - infliximab, rituximab) may be alternative approaches when OLP does not respond to the standard protocols. In this scenario, there are several studies on molecules different from glucocorticosteroids, but not sufficient or statistically adequate to justify their evidence-based use in OLP; large randomized placebo controlled trials are required to evaluate the safety and effectiveness of these non conventional therapies. In conclusion, since OLP is a chronic disease and requires long-term management, the dental/medical practitioner, who treats OLP patients, needs to know the natural history of OLP, how to monitor, and how to treat, taking in account all of the available modalities conventional and not, with pros and cons.

Direct visualization of oral-cavity tissue fluorescence as novel aid for early oral cancer diagnosis and potentially malignant disorders monitoring

Direct visualization of the oral tissue autofluorescence has been recently reviewed in several studies as a possible adjunctive tool for early recognition and diagnosis of potentially malignant and malignant oral disorders. The aims of this study were to assess: a) the value of a simple handheld device for tissue auto-fluorescence visualization of potentially malignant oral lesions; and b) the sensitivity, specificity and diagnostic accuracy of tested device, using histological examination as the gold standard. 175 consecutive patients, with at least one clinical oral lesion, were enrolled in the study. Clinical conventional inspections were performed for each patient by two blind operators. Then, oral biopsy and histological examination were performed. Pathologist was blind with respect to the autofluorescence results. The 175 histological assessments revealed no dysplasia, mild dysplasia, moderate/severe dysplasia and OSCC, in the 67.4%, 8.6%, 8%, 16% of cases, respectively. Oral lesions diagnosed as OSCC were found as positive under fluorescent light in the 96.4% of cases. Statistically significant correlation was observed between oral dysplastic lesions and the loss of tissue fluorescence (p-value=0.001). Low sensitivity values (60% and 71%) were recorded about the ability of the device in differentiating mild dysplasia vs. lack of dysplasia and moderate/severe dysplasia vs absence of dysplasia, respectively. The device tested in our study was found to not replace the histopathology procedure. However, we assessed its usefulness for oral tissue examination, especially within an oral medicine secondary care facility, before performing a biopsy and in monitoring oral lesions.

Oral HPV Infection: Current Strategies for Prevention and Therapy

Infection with High Risk (HR) Human Papillomaviruses (HPVs) is the main aetiological agent of Cervical Squamous Cell Carcinoma (CSCC) and also associated in a subgroup of other neoplasms, including Oropharyngeal Squamous cell Carcinoma (OPSCC). HPV infection, in genital as in oral mucosa, can also be subclinical or associated with benign proliferative lesions (common warts, condylomas, papillomas) caused mostly by infection with Low Risk (LR)-HPVs. In the last decades, extensive research has resulted in growing knowledge on HPV biology and specifically viral life cycle, biochemical properties of viral proteins and their interaction with the host proteins leading to potential new targets of prophylactic or therapeutic vaccines and therapies for HPV infection. In addition, notable progresses have been made in the field of diagnostics to detect HPV DNA or RNA. The recent epidemiological data suggest the significant changes in HPV endemic, due to the changes in sexual habits especially among young generations (i.e. early sexual debuts, multiple sexual partners, oral and anal sex); this scenario has urged on the need of adequate campaigns of primary (sexual education, vaccination programs) and secondary prevention (diagnostics of HPV-related diseases). Due to the growing interest on HPV infection and HPV related cancers, the authors made a narrative review of the literature on oral HPV infection and oral-genital transmission. After this, in view of the controversies about the strategies of therapy and prevention of HPV infection, the present review focuses on the current state of art about the available tools for the therapeutic and, if any, preventive management of oral HPV infection.