Mucoadhesive thin films for the simultaneous delivery of microbicide and anti-inflammatory drugs in the treatment of periodontal diseases

Current Drug Delivery Strategies for Buccal Cavity Ailments using Mouth Dissolving Wafer Technology: A Comprehensive Review on the Present State of the Art

BACKGROUND

Mouth-dissolving wafer is polymer-based matrice that incorporates various pharmaceutical agents for oral drug delivery. This polymeric wafer is ingenious in the way that it needs not be administered with water, like in conventional tablet dosage form. It has better compliance among the pediatric and geriatric groups owing to its ease of administration.

OBJECTIVE

The polymeric wafer dissolves quickly in the oral cavity and is highly effective for a targeted local effect in buccal-specific ailments. It is a safe, effective, and versatile drug delivery carrier for a range of drugs used to treat a plethora of oral cavity-specific ailments that inflict common people, like thrush, canker sores, periodontal disease, benign oral cavity tumors, buccal neoplasm, and malignancies. This review paper focuses thoroughly on the present state of the art in mouth-dissolving wafer technology for buccal drug delivery and targeting. Moreover, we have also addressed present-time limitations associated with wafer technology to aid researchers in future developments in the arena of buccal drug delivery.

CONCLUSION

This dynamic novel formulation has tremendous future implications for designing drug delivery systems to target pernicious ailments and diseases specific to the buccal mucosa. In a nutshell, this review paper aims to summarize the present state of the art in buccal targeted drug delivery.

Synthesis of films based on chitosan and protic ionic liquids to be used as wound dressing on the oral mucosa

Oral mucosal ulcerations expose connective tissue to different pathogens and this can progress to systemic infection. This study aimed to synthesize environmentally-friendly films with chitosan and protic ionic liquids, possessing mucoadhesive properties, activity against opportunistic microorganisms, enhanced malleability and mechanical resistance to be used as a wound dressing on the oral mucosa. Therefore, films with chitosan and 10, 35, and 50 % (wt/wt) of 2-hydroxy diethylammonium lactate, salicylate, and maleate protic ionic liquids were synthesized. Thickness measurements and mechanical properties analysis were performed. In addition, oral mucoadhesion, antimicrobial activity, and cytotoxicity properties were investigated. Results showed that the addition of 35wt% and 50wt% of all kinds of protic ionic liquids tested presented significant improvements in film thickness and mechanical properties. Films based on chitosan and the protic ionic liquid 2-hydroxy diethylammonium salicylate at percentages of 35 and 50wt% exhibited superior mucoadhesive properties, antimicrobial activity on opportunistic microorganisms and an improvement in their flexibility after immersion in synthetic saliva. Cytotoxicity results suggest that all kinds of chitosan/protic ionic liquids films tested are safe for intra-oral use. Therefore, the results of this study indicate that these materials could be good candidates for efficient and environmentally-friendly wound dressing films on the oral mucosa.

Mucoadhesive Pharmacology: Latest Clinical Technology in Antiseptic Gels

Chlorhexidine (CHX) is one of the most widely used antiseptics in the oral cavity due to its high antimicrobial potential. However, many authors have stated that the effect of CHX in nonsurgical periodontal therapy is hampered by its rapid elimination from the oral environment. The aim of this study was to determine the antibacterial efficacy of a new compound of chlorhexidine 0.20% + cymenol (CYM) 0.10% on a multispecies biofilm. For this, an in vitro study was designed using a multispecies biofilm model of Streptococcus mutans, Fusobacterium nucleatum, Prevotella intermedia, and Porphyromonas gingivalis. Quantification of the microbial viability of the biofilm was performed using 5-cyano-2,3-ditolyl tetrazolium-chloride (CTC) to calculate the percentage of survival, and the biofilms were observed using a a confocal laser scanning microscopy (CLSM). It was observed that the bactericidal activity of the CHX + cymenol bioadhesive gel was superior to that of the CHX bioadhesive gel, in addition to higher penetrability into the biofilm. Therefore, there was greater elimination of bacterial biofilm with the new compound of chlorhexidine 0.2% plus cymenol 0.1% in a bioadhesive gel form compared to the formulation with only chlorhexidine 0.2% in a bioadhesive gel form.

Factorial design of in situ gelling two-compartment systems containing chlorhexidine for the treatment of periodontitis

Periodontitis is one of the most widespread bacterial infectious oral diseases that affects a significant percentage of the population worldwide. Different bacterial strains are responsible for the chronic inflammation and subgingival plaque that could be effectively treated with prolonged exposure to therapeutic levels of antibiotics and antiseptics in the periodontal pockets. Medicated in situ gels of chlorhexidine (CHX), for extended drug release and long-lasting antiseptic effect in the targeted cavities, were prepared in a two-compartment system. One compartment was loaded with sodium alginate solution while other was filled with CHX and calcium solution. The mixing of the solutions during the application resulted in gelation. Two 33 full factorial designs were applied in this study in order to optimize the gel formulation. Initially, the effects of concentration of gelling agent, crosslinker, and pH of the system on the dependent variables such as gel formation and structure characteristics were investigated. Then, the concentration of the crosslinker was optimized. Afterwards, the effect of gelling agent, loading of the drug, and pH of the gel system were correlated with the gel characteristics through another factorial design. Optimized formulations were tested for mucoadhesion, in vitro drug release, and microbiological investigation. Based on the results of the factorial design, mucoadhesiveness, antimicrobial investigation, and drug release, a 4 % alginate composition can be considered optimal. Overall, the optimized in situ periodontal gel was found to be effective with prolonged retention time and desirable outcomes.

Iontophoresis on Porcine and Human Gingiva

PURPOSE

Iontophoresis is a noninvasive method that enhances drug delivery using an electric field. This method can improve drug delivery to the tissues in the oral cavity. The effects of iontophoresis on gingival drug delivery have not been investigated. The objectives of this study were to (a) determine the flux enhancement of model permeants across porcine and human gingiva during iontophoresis, (b) examine the transport mechanisms of gingival iontophoresis, and (c) evaluate the potential of iontophoretically enhanced delivery for three model drugs lidocaine, ketorolac, and chlorhexidine.

METHODS

Passive and iontophoretic fluxes were determined with porcine and human gingiva using a modified Franz diffusion cell and model drugs and permeants. To investigate the transport mechanisms of iontophoresis, the enhancement from the direct-field effect was determined by positively and negatively charged model permeants. The electroosmosis enhancement effect was determined with neutral permeants of different molecular weight. The alteration of the gingival barrier due to electropermeabilization was evaluated using electrical resistance measurements.

RESULTS

Significant flux enhancement was observed during gingival iontophoresis. The direct-field effect was the major mechanism governing the iontophoretic transport of the charged permeants. Electroosmosis was from anode to cathode. The effective pore radius of the iontophoretic transport pathways in the porcine gingiva was ~0.68 nm. Irreversible electropermeabilization was observed after 2 and 4 h of iontophoresis under the conditions studied.

CONCLUSION

Iontophoresis could enhance drug delivery and reduce transport lag time, showing promise for gingival drug delivery.

Are Local Drug Delivery Systems a Challenge in Clinical Periodontology?

Placing antimicrobial treatments directly in periodontal pockets is an example of the local administration of antimicrobial drugs to treat periodontitis. This method of therapy is advantageous since the drug concentration after application far surpasses the minimum inhibitory concentration (MIC) and lasts for a number of weeks. As a result, numerous local drug delivery systems (LDDSs) utilizing various antibiotics or antiseptics have been created. There is constant effort to develop novel formulations for the localized administration of periodontitis treatments, some of which have failed to show any efficacy while others show promise. Thus, future research should focus on the way LDDSs can be personalized in order to optimize future clinical protocols in periodontal therapy.

Local Delivery and Controlled Release Drugs Systems: A New Approach for the Clinical Treatment of Periodontitis Therapy

Periodontitis is an inflammatory disease of the gums characterized by the degeneration of periodontal ligaments, the formation of periodontal pockets, and the resorption of the alveolar bone, which results in the destruction of the teeth's supporting structure. Periodontitis is caused by the growth of diverse microflora (particularly anaerobes) in the pockets, releasing toxins and enzymes and stimulating the immune system. Various approaches, both local and systemic, have been used to treat periodontitis effectively. Successful treatment depends on reducing bacterial biofilm, bleeding on probing (BOP), and reducing or eliminating pockets. Currently, the use of local drug delivery systems (LDDSs) as an adjunctive therapy to scaling and root planing (SRP) in periodontitis is a promising strategy, resulting in greater efficacy and fewer adverse effects by controlling drug release. Selecting an appropriate bioactive agent and route of administration is the cornerstone of a successful periodontitis treatment plan. In this context, this review focuses on applications of LDDSs with varying properties in treating periodontitis with or without systemic diseases to identify current challenges and future research directions.

A novel in vitro periodontal pocket model to evaluate the effect of root surface instrumentation on biofilm-epithelial cell interactions

Objective

To develop a novel in vitro periodontal pocket model for evaluating the effect of two different root surface instrumentation modalities on biofilm-epithelial cell interactions.

Materials and methods

An artificial periodontal pocket model was created using an impression material. Dentin discs were prepared and incubated for 3.5 days with a biofilm consisting of 12 bacterial strains. Then, the discs were inserted into the pocket model and instrumented for 10 s or 10 strokes either with ultrasonics (US) or hand instruments (HI). Subsequently, a glass slide coated with epithelial cells was placed in close vicinity to the discs. After incubation of the pocket model in a 5% CO2 atmosphere for 6 h, residual bacteria of the biofilm as well as bacteria adhering to or invaded into epithelial cells were determined using colony-forming unit (cfu) counts and real-time PCR. Further, as a parameter of the pro-inflammatory cell response, interleukin (IL)-8 expression was determined by ELISA.

Results

Compared to untreated control, HI reduced the cfu counts by 0.63 log10 (not significant) and US by 1.78 log10 (p = 0.005) with a significant difference between the treatment modalities favoring US (p = 0.048). By trend, lower detection levels of Tannerella forsythia were detected in the US group compared to HI. Concerning the interaction with epithelial cells, half of the control and the HI samples showed epithelial cells with attaching or invading bacteria, while US displayed bacteria only in two out of eight samples. In addition, US resulted in significantly lower IL-8 secretion by epithelial cells compared to the untreated control. Between HI and controls, no statistically significant difference in IL-8 secretion was found.

Conclusion

This newly developed in vitro model revealed in terms of biofilm-epithelial cell interaction after root surface instrumentation that compared to hand curettes, ultrasonic instrumentation appeared to be more effective in removing bacterial biofilm and in decreasing the inflammatory response of epithelium to biofilm.

Clinical relevance

Ultrasonic instrumentation might be more advantageous to reduce cellular inflammatory response than hand instruments.

Gellan Gum-Based Bilayer Mucoadhesive Films Loaded with Moxifloxacin Hydrochloride and Clove Oil for Possible Treatment of Periodontitis

Background/Objective

Periodontitis is a widely spread oral infection and various antibiotics are utilized for its treatment, but high oral doses and development of antibiotic resistance limit their use. This study was aimed at development of natural polymer-based mucoadhesive bilayer films loaded with moxifloxacin hydrochloride (Mox) and clove essential oil (CEO) to potentially combat bacterial infection associated with periodontitis.

Methods

Films were synthesized by double solvent casting technique having an antibiotic in the gellan gum-based primary layer with clove oil in a hydroxyethyl cellulose-based secondary layer.

Results

Prepared films were transparent, flexible, and showed high antibacterial response against both gram-positive and gram-negative bacteria. The films showed excellent pharmaceutical attributes in terms of drug content, folding endurance, swelling index, and mucoadhesive strength. Solid state characterization of formulation showed successful incorporation of drug and oil in separate layers of hydrogel structure. An in-vitro release study showed an initial burst release of drug followed by sustained release for up to 48 hours.

Conclusion

The prepared mucoadhesive bilayer buccal films could be used as a potential therapeutic option for the management of periodontitis.

Characterization of Chlorhexidine-Impregnated Cellulose-Based Hydrogel Films Intended for the Treatment of Periodontitis

Periodontitis comprises a chronic inflammation that is initiated by microbiota biofilm. If left untreated, periodontitis may lead to permanent tooth loss. Herein, we propose to design and improve a localized form of therapy comprising a chlorhexidine-impregnated hydrogel. Hydrogel films were prepared by varying the ratio between cellulose (MCC) and carboxymethylcellulose sodium (CMC) using the crosslinker epichlorohydrin (ECH). The hydrogel was loaded with chlorhexidine. Increasing the CMC ratio led to a reduction in the number of pores, an increase in their size, lower glass transition temperature (T g ), decreased Young's modulus, and increased film stretching and affected the time of release. Bacterial and fungal zones of inhibition showed similar activity and were not affected by the CMC and MCC ratio. Hydrogels loaded with chlorhexidine prevented the growth of S. oralis and C. albicans microorganisms and may provide a promising local delivery system for treating periodontitis.

Recent advances of oral film as platform for drug delivery

Orally drug delivery film has received extensive interest duo to a distinct set of its advantageous properties compared to the traditional orally administered dosages, including faster rate of drug absorption, higher bioavailability and better patient compliance for children and elders with swallowing deficiencies. In particular, its potential capacity of delivering proteins and peptides has further attracted great attention. Lately, tremendous advances have been made in designing and developing both novel mucoadhesive films and orodispersible films to fulfill specific accomplishments of drug delivery. This review aims to summarize those newly developed oral films, discussing their formulation strategies, manufacturing methods as well as advantages and limitations thereof. Conclusions and future perspectives are also provided in brief.

Local drug delivery systems as therapeutic strategies against periodontitis: A systematic review

Periodontitis is a chronic inflammation of the soft tissue surrounding and supporting the teeth, which causes periodontal structural damage, alveolar bone resorption, and even tooth loss. Its prevalence is very high, with nearly 60% of the global population affected. Hence, periodontitis is an important public health concern, and the development of effective healing treatments for oral diseases is a major target of the health sciences. Currently, the application of local drug delivery systems (LDDS) as an adjunctive therapy to scaling and root planning (SRP) in periodontitis is a promising strategy, giving higher efficacy and fewer side effects by controlling drug release. The cornerstone of successful periodontitis therapy is to select an appropriate bioactive agent and route of administration. In this context, this review highlights applications of LDDS with different properties in the treatment of periodontitis with or without systemic diseases, in order to reveal existing challenges and future research directions.

Current status and future of delivery systems for prevention and treatment of infections in the oral cavity

Oral health reflects the general health, and it is fundamental to well-being and quality of life. An infection in the oral cavity can be associated with serious complications in human health. Local therapy of these infections offers many advantages over systemic drug administration, targeting directly to the diseased area while minimizing systemic side effects. Specialized drug delivery systems into the oral cavity have to be designed in such a fashion that they resist to the aqueous environment that is constantly bathed in saliva and subject to mechanical forces. Additionally, a prolonged release of drug should also be provided, which would enhance the efficacy and also decrease the repeated dosing. This review is aimed to summarize the current most relevant findings related to local drug delivery of various drug groups for prevention and treatment of infections (viral, bacterial, fungal) and infection-related manifestations in the oral cavity. Current therapeutic challenges in regard to effective local drug delivery systems will be discussed, and the recent approaches to overcome these obstacles will be reviewed. Finally, future prospects will be overviewed to promote novel strategies that can be implemented in clinical management for prevention and treatment of oral infections.

Recent Advances in Antiinflammatory Material Design

Implants and prostheses are widely used to replace damaged tissues or to treat various diseases. However, besides the risk of bacterial or fungal infection, an inflammatory response usually occurs. Here, recent progress in the field of anti-inflammatory biomaterials is described. Different materials and approaches are used to decrease the inflammatory response, including hydrogels, nanoparticles, implant surface coating by polymers, and a variety of systems for anti-inflammatory drug delivery. Complex multifunctional systems dealing with inflammation, microbial infection, bone regeneration, or angiogenesis are also described. New promising stimuli-responsive systems, such as pH- and temperature-responsive materials, are also being developed that would enable an "intelligent" antiinflammatory response when the inflammation occurs. Together, different approaches hold promise for creation of novel multifunctional smart materials allowing better implant integration and tissue regeneration.

Manufacturing and characterisation of a novel composite dosage form for buccal drug administration

The potential of alternative routes of application compared to the traditional oral route is constantly growing. Especially in transmucosal applications for the oral cavity, easy accessibility is an attractive feature with many new opportunities. The combination of a minitablet and a buccal mucoadhesive carrier film has been shown to enable safe and accurate drug administration compared to semi-solid formulations currently available on the market. In order to investigate these so-called composite dosage forms in more detail, two different manufacturing methods were compared within this study to investigate the resulting properties. The formulation development of the minitablets containing lidocaine, complying with the compendial requirements, resulted in immediate release using both manufacturing methods (more than 80% lidocaine release after 3-4 min using direct incorporation, 7-8 min by the gluing method). Differences in morphology and drug migration behaviour could be observed. The directly incorporated minitablets revealed a twofold higher drug migration (1.5 mm) into the mucoadhesive shielding film within two weeks compared to the glued minitablets (0.8 mm). These findings enable a further optimization of the formulation depending on the duration of the application and the feasibility for the addressed patient population.

Polymeric Carriers for Delivery Systems in the Treatment of Chronic Periodontal Disease

Periodontitis (PD) is a chronic inflammatory disease of periodontal tissues caused by pathogenic microorganisms and characterized by disruption of the tooth-supporting structures. Conventional drug administration pathways in periodontal disease treatment have many drawbacks such as poor biodistribution, low selectivity of the therapeutic effect, burst release of the drug, and damage to healthy cells. To overcome this limitation, controlled drug delivery systems have been developed as a potential method to address oral infectious disease ailments. The use of drug delivery devices proves to be an excellent auxiliary method in improving the quality and effectiveness in periodontitis treatment, which includes inaccessible periodontal pockets. This review explores the current state of knowledge regarding the applications of various polymer-based delivery systems such as hydrogels, liposomes, micro-, and nanoparticles in the treatment of chronic periodontal disease. Furthermore, to present a more comprehensive understanding of the difficulties concerning the treatment of PD, a brief description of the mechanism and development of the disease is outlined.