Mucoadhesive Poloxamer-Based Hydrogels for the Release of HP-beta-CD-Complexed Dexamethasone in the Treatment of Buccal Diseases

International audienceOral lichen planus (OLP) is an ongoing and chronic inflammatory disease affecting the mucous membrane of the oral cavity. Currently, the treatment of choice consists in the direct application into the buccal cavity of semisolid formulations containing a corticosteroid molecule to decrease inflammatory signs and symptoms. However, this administration route has shown various disadvantages limiting its clinical use and efficacy. Indeed, the frequency of application and the incorrect use of the preparation may lead to a poor efficacy and limit the treatment compliance. Furthermore, the saliva clearance and the mechanical stress present in the buccal cavity also involve a decrease in the mucosal exposure to the drug. In this context, the design of a new pharmaceutical formulation, containing a steroidal anti-inflammatory, mucoadhesive, sprayable and exhibiting a sustained and controlled release seems to be suitable to overcome the main limitations of the existing pharmaceutical dosage forms. The present work reports the formulation, optimization and evaluation of the mucoadhesive and release properties of a poloxamer 407 thermosensitive hydrogel containing a poorly water-soluble corticosteroid, dexamethasone acetate (DMA), threaded into hydroxypropyl-beta-cyclodextrin (HP-beta-CD) molecules. Firstly, physicochemical properties were assessed to ensure suitable complexation of DMA into HP-beta-CD cavities. Then, rheological properties, in the presence and absence of various mucoadhesive agents, were determined and optimized. The hydration ratio (0.218-0.191), the poloxamer 407 (15-17 wt%) percentage and liquid-cyclodextrin state were optimized as a function of the gelation transition temperature, viscoelastic behavior and dynamic flow viscosity. Deformation and resistance properties were evaluated in the presence of various mucoadhesive compounds, being the sodium alginate and xanthan gum the most suitable to improve adhesion and mucoadhesion properties. Xanthan gum was shown as the best agent prolonging the hydrogel retention time up to 45 min. Furthermore, xanthan gum has been found as a relevant polymer matrix controlling drug release by diffusion and swelling processes in order to achieve therapeutic concentration for prolonged periods of time

Novel in situ gelling ophthalmic drug delivery system based on gellan gum and hydroxyethylcellulose: Innovative rheological characterization, in vitro and in vivo evidence of a sustained precorneal retention time

International audienceAchieving drug delivery at the ocular level encounters many challenges and obstacles. In situ gelling delivery systems are now widely used for topical ocular administration and recognized as a promising strategy to improve the treatment of a wide range of ocular diseases. The present work describes the formulation and evaluation of a mucoadhesive and ion-activated in situ gelling delivery system based on gellan gum and hydroxyethylcellulose for the delivery of phenylephrine and tropicamide. First, physico-chemical characteristics were assessed to ensure suitable properties regarding ocular administration. Then, rheological properties such as viscosity and gelation capacity were determined. Gelation capacity of the formulations and the effect of hydroxyethylcellulose on viscosity were demonstrated. A new rheological method was developed to assess the gel resistance under simulated eye blinking. Afterward, mucoadhesion was evaluated using tensile strength test and rheological synergism method in both rotational and oscillatory mode allowing mucoadhesive properties of hydroxyethylcellulose to be point out. Finally, residence time on the ocular surface was investigated in vivo, using cyanine 5.5 dye as a fluorescent marker entrapped in the in situ gelling delivery systems. Residence performance was studied by non-invasive optical imaging on vigilant rabbits, allowing eye blinking and nasolacrimal drainage to occur physiologically. Fluorescence intensity profiles pointed out a prolonged residence time on the ocular surface region for the developed formulations compared to conventional eye drops, suggesting in vitro/in vivo correlations between rheological properties and in vivo residence performances

Dosage form suitability in vulnerable populations: A focus on paracetamol acceptability from infants to centenarians

International audienceIntroduction Medicine acceptability is a multi-faceted concept driven by both product and user characteristics. Although a key factor for treatment effectiveness, especially in vulnerable populations, knowledge of those medicine features that best promote individual user acceptability remains fragmented. Focusing on paracetamol, this study has explored the appropriateness of pharmaceutical products in different dosage forms to achieve adequate patient acceptability from infants to centenarians. Methods This observational, multicentre, prospective study was carried out in 10 hospitals, 8 nursing homes and over 150 community dispensaries. Observers reported several behaviours/events evaluating acceptability for 1016 different pharmaceutical product uses in paediatrics (= 65y.). Using mapping and clustering, a multivariate approach offered an intelligible reference framework for each population, providing comprehensive scores: positively or negatively accepted. Results Among all the evaluations supporting the acceptability reference frameworks, there were 502 reports on paracetamol products intake. Herein we focused on the 5 products with. 30 evaluations. Although oral suspension and powder for oral solution were positively-accepted in the paediatric group, the powder had a higher rate of negative patient reaction (p= 90y., capsule formulations appeared to be the best accepted product in patients without swallowing alterations, and thus could be a suitable alternative to the powder in this population. Conclusions By better integrating patient characteristics when choosing dosage forms, clinicians and caregivers may improve treatment acceptability and adherence. Moreover, hospitals and healthcare institutions could optimise purchasing to best suit their local population, disseminating information to help staff align specific dosage forms to targeted patients

Sex Differences in Medicine Acceptability: A New Factor to Be Considered in Medicine Formulation

International audiencePalatability is a recognized driver of medicine acceptability in pediatrics but deemed less relevant in older populations due to sensory decline. Preliminary findings from an observational study implicated palatability problems with one Alzheimer's medicine. Among 1517 observer reports combining multiple measures on medicines uses in patients aged over 64, we focused on two original formulations of memantine (Ebixa (R), tablets (n = 25) and oral solution (n = 60)). Evaluations were scored with an acceptability reference framework (CAST), the rodent Brief Access Taste Aversion (BATA) model tested aversiveness. Focusing on women treated with Ebixa (R) (n = 54), the oral formulation sub-group was classified as negatively accepted, while the coated tablet was associated with the positively accepted cluster. In men, both formulations belonged to the positively accepted profile. Using BATA, the original oral solution was categorized as highly aversive/untolerated while solutions of excipients only were well tolerated. Furthermore, the number of licks was significantly lower in female than in male rats. These results revealed that medicine palatability remains important for acceptability in older populations. Moreover, converging results from humans and animal models highlighted that palatability profiles can significantly vary between the sexes. These drivers should be closely considered during drug development to enhance acceptability in this population