Efficacy of 0.1% triamcinolone with nanoliposomal carrier formulation in orabase for oral lichen planus patients: A clinical trial

Applications of Novel and Nanostructured Drug Delivery Systems for the Treatment of Oral Cavity Diseases

PURPOSE

Novel drug delivery systems (DDSs) hold great promise for the treatment of oral cavity diseases. The main objective of this article was to provide a detailed overview regarding recent advances in the use of novel and nanostructured DDSs in alleviating and treating unpleasant conditions of the oral cavity. Strategies to maximize the benefits of these systems in the treatment of oral conditions and future directions to overcome these issues are also discussed.

METHODS

Publications from the last 10 years investigating novel and nanostructured DDSs for pathologic oral conditions were browsed in a systematic search using the PubMed/MEDLINE, Web of Science, and Scopus databases. Research on applications of novel DDSs for periodontitis, oral carcinomas, oral candidiasis, xerostomia, lichen planus, aphthous stomatitis, and oral mucositis is summarized. A narrative exploratory review of the most recent literature was undertaken.

FINDINGS

Conventional systemic administration of therapeutic agents could exhibit high clearance of drugs from the bloodstream and low accumulation at the target site. In contrast, conventional topical systems face problems such as short residence time in the affected region and low patient compliance. Novel and nanostructured DDSs are among the most effective and commonly used methods for overcoming the problems of conventional DDSs. The main advantages of these systems are that they possess the ability to protect active agents from systemic and local clearance, enhance bioavailability and cellular uptake, and provide immediate or modified release of therapeutic agents after administration. In the design of local drug delivery devices such as nanofiber mats, films, and patches, components and excipients can significantly affect factors such as drug release rate, residence time in the oral cavity, and taste in the mouth. Choosing appropriate additives is therefore essential.

IMPLICATIONS

Local drug delivery devices such as nanofiber mats, nanoparticles, liposomes, hydrogels, films, and patches for oral conditions can significantly affect drug efficacy and safety. However, more precise clinical studies should be designed and conducted to confirm promising in vitro and in vivo results. In recent years, novel and nanostructured DDSs increasingly attracted the attention of researchers as a means of treatment and alleviation of oral diseases and unpleasant conditions. However, more clinical studies should be performed to confirm promising in vitro and in vivo results. To transform a successful laboratory model into a marketable product, the long-term stability of prepared formulations is essential. Also, proper scale-up methods with optimum preparation costs should be addressed.

Interventions for treating oral lichen planus: corticosteroid therapies

BACKGROUND

Oral lichen planus (OLP) is a relatively common chronic T cell-mediated disease, which can cause significant pain, particularly in its erosive or ulcerative forms. As pain is the indication for treatment of OLP, pain resolution is the primary outcome for this review. This review is an update of a version last published in 2011, but focuses on the evidence for corticosteroid treatment only. A second review considering non-corticosteroid treatments is in progress.

OBJECTIVES

To assess the effects and safety of corticosteroids, in any formulation, for treating people with symptoms of oral lichen planus.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases to 25 February 2019: Cochrane Oral Health's Trials Register, CENTRAL (2019, Issue 1), MEDLINE Ovid, and Embase Ovid. ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. There were no restrictions on language or date of publication.

SELECTION CRITERIA

We considered randomised controlled clinical trials (RCTs) of any local or systemic corticosteroid treatment compared with a placebo, a calcineurin inhibitor, another corticosteroid, any other local or systemic (or both) drug, or the same corticosteroid plus an adjunctive treatment.

DATA COLLECTION AND ANALYSIS

Three review authors independently scanned the titles and abstracts of all reports identified, and assessed risk of bias using the Cochrane tool and extracted data from included studies. For dichotomous outcomes, we expressed the estimates of effects of an intervention as risk ratios (RR), with 95% confidence intervals (CI). For continuous outcomes, we used mean differences (MD) and 95% CI. The statistical unit of analysis was the participant. We conducted meta-analyses only with studies of similar comparisons reporting the same outcome measures. We assessed the overall certainty of the evidence using GRADE.

MAIN RESULTS

We included 35 studies (1474 participants) in this review. We assessed seven studies at low risk of bias overall, 11 at unclear and the remaining 17 studies at high risk of bias. We present results for our main outcomes, pain and clinical resolution measured at the end of the treatment course (between one week and six months), and adverse effects. The limited evidence available for comparisons between different corticosteroids, and corticosteroids versus alternative or adjunctive treatments is presented in the full review. Corticosteroids versus placebo Three studies evaluated the effectiveness and safety of topical corticosteroids in an adhesive base compared to placebo. We were able to combine two studies in meta-analyses, one evaluating clobetasol propionate and the other flucinonide. We found low-certainty evidence that pain may be more likely to be resolved when using a topical corticosteroid rather than a placebo (RR 1.91, 95% CI 1.08 to 3.36; 2 studies, 72 participants; I² = 0%). The results for clinical effect of treatment and adverse effects were inconclusive (clinical resolution: RR 6.00, 95% CI 0.76 to 47.58; 2 studies, 72 participants; I² = 0%; very low-certainty evidence; adverse effects RR 1.48, 95% 0.48 to 4.56; 3 studies, 88 participants, I² = 0%, very low-certainty evidence). Corticosteroids versus calcineurin inhibitors Three studies compared topical clobetasol propionate versus topical tacrolimus. We found very low-certainty evidence regarding any difference between tacrolimus and clobetasol for the outcomes pain resolution (RR 0.45, 95% CI 0.24 to 0.88; 2 studies, 100 participants; I² = 80%), clinical resolution (RR 0.61, 95% CI 0.38 to 0.99; 2 studies, 52 participants; I² = 95%) and adverse effects (RR 0.05, 95% CI 0.00 to 0.83; 2 studies, 100 participants; very low-certainty evidence) . One study (39 participants) compared topical clobetasol and ciclosporin, and provided only very low-certainty evidence regarding the rate of clinical resolution with clobetasol (RR 3.16, 95% CI 1.00 to 9.93), pain resolution (RR 2.11, 95% CI 0.76 to 5.86) and adverse effects (RR 6.32, 95% CI 0.84 to 47.69). Two studies (60 participants) that compared triamcinolone and tacrolimus found uncertain evidence regarding the rate of clinical resolution (RR 0.86, 95% CI 0.55 to 1.35; very low-certainty evidence) and that there may be a lower rate of adverse effects in the triamcinolone group (RR 0.47, 95% CI 0.22 to 0.99; low-certainty evidence). These studies did not report on pain resolution.

AUTHORS' CONCLUSIONS

Corticosteroids have been first line for the treatment of OLP. This review found that these drugs, delivered topically as adhesive gels or similar preparations, may be more effective than placebo for reducing the pain of symptomatic OLP; however, with the small number of studies and participants, our confidence in the reliability of this finding is low. The results for clinical response were inconclusive, and we are uncertain about adverse effects. Very low-certainty evidence suggests that calcineurin inhibitors, specifically tacrolimus, may be more effective at resolving pain than corticosteroids, although there is some uncertainty about adverse effects and clinical response to tacrolimus showed conflicting results.

Microemulsion containing triamcinolone acetonide for buccal administration

The aim of the present work was to investigate the potential of microemulsions for the buccal administration of triamcinolone acetonide. Microemulsions were developed by the construction of pseudoternary phase diagrams, using the aqueous titration method. Among all microemulsions prepared and tested for stability, three were selected and submitted to characterization and in vitro permeation/retention experiments, using pig esophageal epithelium, an accepted model of the buccal mucosa. Furthermore, one microemulsion was added of excipients (stearylamine, CTAB and chitosan) able to alter the charge of droplets. The results obtained show that the permeation of triamcinolone acetonide across pig esophageal epithelium was not influenced by the droplet size nor by the composition, but only by the presence of chitosan, polysaccharide able to increase the transport across mono and stratified epithelia. The determination of the permeation parameters allowed us to show that chitosan acts on the diffusion parameter across the tissue and not on the partitioning parameter; for the same reason the tissue retention of triamcinolone acetonide was not modified. Triamcinolone flux (2.6 μg cm^-2 h^-1) was too low to make systemic administration feasible (dose required 2.5 to 60 mg/day). The amount of triamcinolone acetonide recovered in the mucosa after only 10 min. of microemulsion application was much higher than after overnight application of the commercial paste Omicilon® A. This suggests that triamcinolone acetonide microemulsions can be an interesting alternative to the commercial formulation to treat diseases of the buccal mucosa. Owing to the fast uptake by the tissue, the formulation can be used as a mouthwash.