Technological Aspects and Evaluation Methods for Polymer Matrices as Dental Drug Carriers.

The development of polymer matrices as dental drug carriers takes into account the following technological aspects of the developed formulations: the composition and the technology used to manufacture them, which affect the properties of the carriers, as well as the testing methods for assessing their behavior at application sites. The first part of this paper characterizes the methods for fabricating dental drug carriers, i.e., the solvent-casting method (SCM), lyophilization method (LM), electrospinning (ES) and 3D printing (3DP), describing the selection of technological parameters and pointing out both the advantages of using the mentioned methods and their limitations. The second part of this paper describes testing methods to study the formulation properties, including their physical and chemical, pharmaceutical, biological and in vivo evaluation. Comprehensive in vitro evaluation of carrier properties permits optimization of formulation parameters to achieve prolonged retention time in the dynamic oral environment and is essential for explaining carrier behavior during clinical evaluation, consequently enabling the selection of the optimal formulation for oral application.

Fractal Dimension and Texture Analysis of Lesion Autofluorescence in the Evaluation of Oral Lichen Planus Treatment Effectiveness.

BACKGROUND: Oral Lichen planus (OLP) is a chronic inflammatory disease. Topical steroids are used as the treatment of choice. The alternative is photodynamic therapy (PDT). The study aimed to fabricate optimal biodegradable matrices for methylene blue or triamcinolone acetonide because of a lack of currently commercially available carriers that could adhere to the mucous. METHODS: The study was designed as a 12-week single-blind prospective randomized clinical trial with 30 patients, full contralateral split-mouth design. Matrices for steroid and photosensitizer and laser device were fabricated. Fractal and texture analysis of photographs, taken in 405, 450, 405 + 450 nm wavelength, of lesions was performed to increase the objectivity of the assessment of treatment. RESULTS: We achieved two total responses for treatment in case of steroid therapy and one in the case of PDT. Partial response was noted in 17 lesions treated using local steroid therapy and 21 in the case of PDT. No statistically significant differences were found between the effectiveness of both used methods. Statistically significant differences in fractal dimension before and after treatment were observed only in the analysis of photographs taken in 405 + 450 nm wavelength. CONCLUSIONS: Photodynamic therapy and topical steroid therapy are effective methods for treating OLP. Using a carrier offers the possibility of a more predictable and effective method of drug delivery into the mucous membrane. Autofluorescence enables the detection of lesions especially at the early stage of their development.

A Comparison of Clinical Efficiency of Photodynamic Therapy and Topical Corticosteroid in Treatment of Oral Lichen Planus: A Split-Mouth Randomised Controlled Study.

BACKGROUND: The aim of the study was to compare the effectiveness of photodynamic therapy (PDT) to steroid therapy in the treatment of oral lichen planus (OLP). Due to the lack of commercially available drug carriers, innovative proprietary solutions were used for both the photosensitiser and the steroid carrier-in the first case to shorten and in the second to extend the contact of the active substance with the mucosa. METHODS: A prospective, randomised, single-blind, 12-week full contralateral split-mouth clinical trial of 30 patients with bilateral oral lichen planus was conducted. The prepared matrices were incorporated with active substances methylene blue 5% and 0,05% triamcinolone. The size of lesions, Thongprasom, ABISIS, and VAS scale were evaluated. RESULTS: Relatively high rates of complete remission of lichen were demonstrated: immediately after treatment, 33.3% with PDT and 22.2% with triamcinolone (TA), and after 3 months, 54.2% with PDT and 62.9% with TA. After 3 months of treatment, a reduction in the area of evaluated lesions of 52.7% for PDT and 41.7% for TA was achieved. CONCLUSION: In situations of topical or general contraindications to oral corticosteroids, resistance to them, or the need for repeated treatment in a short period of time, PDT appears to be a very promising treatment option.

Polymer-Based Carriers in Dental Local Healing-Review and Future Challenges.

Polymers in drug formulation technology and the engineering of biomaterials for the treatment of oral diseases constitute a group of excipients that often possess additional properties in addition to their primary function, i.e., biological activity, sensitivity to stimuli, mucoadhesive properties, improved penetration of the active pharmaceutical ingredient (API) across biological barriers, and effects on wound healing or gingival and bone tissue regeneration. Through the use of multifunctional polymers, it has become possible to design carriers and materials tailored to the specific conditions and site of application, to deliver the active substance directly to the affected tissue, including intra-periodontal pocket delivery, and to release the active substance in a timed manner, allowing for the improvement of the form of application and further development of therapeutic strategies. The scope of this review is polymeric drug carriers and materials developed from selected multifunctional groups of natural, semi-synthetic, and synthetic polymers for topical therapeutic applications. Moreover, the characteristics of the topical application and the needs for the properties of carriers for topical administration of an active substance in the treatment of oral diseases are presented to more understand the difficulties associated with the design of optimal active substance carriers and materials for the treatment of lesions located in the oral cavity.

Development and Evaluation of a Polyvinylalcohol -Cellulose Derivative-Based Film with Povidone-Iodine Predicted for Wound Treatment.

The aim of this study was to develop and assess a polyvinyl alcohol-cellulose derivatives-based film with incorporated povidone-iodine (PVP-I) predicted for applications in the treatment of periodontitis. Films were fabricated by solvent-casting, and their physical characteristics, such as their surface and structure morphology, mechanical properties, and disintegrating time, were evaluated. For in vitro iodine release studies and evaluation, the antimicrobial activity was tested using a modified disc diffusion method against five microbial strains. For further use, we selected the film with polyvinyl alcohol-hydroxypropyl methylcellulose (PVA/HPMC_B) based on acceptable physicochemical properties. To assess the subacute toxicity of the film composition, the tissue regeneration process was tested in rats and compared to a conventional dressing commonly used in wound healing (Spongostan). Seven days after implantation, dorsal skin sections and blood samples (n = 10, in total n = 30) were examined. The wound area, epithelium, and dermis were evaluated microscopically, while the blood collected from the rats underwent biochemical analysis. The blood biochemistry results were comparable in all three groups. No significant histological differences between the Spongostan and the placebo film developed after subcutaneous implantation were observed. In contrast, the inflammation stage was reduced and the "scar" in the dermis was smaller when PVP-I and PVA/HPMC_B films were used. A smaller local inflammatory response inflicted less tissue damage, leading to the activation of subsequent regeneration phases and restoration of the area to its original state. The results obtained confirmed that PVP-I incorporated into PVA-hydroxypropyl methylcellulose film is a promising drug carrier, working faster and more effectively than the other two dressing materials evaluated. These developments provide a promising alternative in tissue regeneration and the wound healing process.

[The effect of the composition of stomatological dressings on Carbopol 971P and methylocelullose base on pharmaceutical availability of metronidazole]. / Wplyw skladu preparatów stomatologicznych sporzadzonych na bazie polimerów--Carbopolu 971P i metylocelulozy na dostepnosc farmaceutyczna metronidazolu.

The carried out studies allowed to propose composition of stomatological dressing makes opportunity to ensure preferable physiochemicals features for dosage forms. According to results formulations contain 1.5% Carbopol 971P, 0.13% methylocelullose and various quantity of glycerol, 1,2-propylene glycol and polyethylene glycol 400 were prepared. To compare formulation consists of only polymers dispersion (Carbopol 971P and methylocelullose) was prepared. Next to produced compound triethanoloamine to pH range 5.5-6.5 and 1% metronidazole added. Kinetics test of metronidazole release was performed in vitro using Hanson's cells and semipermable membrane. The quantity of the release metronidazole was determined by spectrophotometric method. Gel consists of 98% polymers dyspersion with 2% glycerol characterized by the largest pharmaceutical availability. The addition of 2% PEG 400 resulted in the decrease of the percentage of released substance in comparison to formulation without hydrophylisers. Metronidazole releasing was more efficient for dressings with 2% glycerol as well propylene glycol. For preparations contains glycerol (2 and 5%) as well propylene glycol as adiuvants, it was found that gels prepared on Carbopol 971P and methylocelullose revealed higher pharmaceutical availability than analogical dressings prepared with only one polymer base.

[The effect of selected hydrophilisers on metronidazole release from hydrogels stomatological dressings on the basis of Carbopol 971]. / Wplyw wybranych substancji hydrofilizujacych na uwalnianie metronidazolu z hydrozelowych opatrunków stomatologicznych na bazie Carbopolu 971P.

The aim of this study was to assess the influence of qualitative and quantitative base composition on pharmaceutical availability of metronidazole. Hydrogels contain water dispersion of 2% Carbopol 971P and various concentration of glycerol, polyethylene glycol and propylene glycol were preparated. Produced formulations were neutralized to the pH 6.0-6.5 with triethanolamine, and metronidazole in concentration 1% added. The test for pharmaceutical bioavailability was performed in vitro, the rate of diffusing therapeutic agent through a semipermable into acceptor fluid was tested. The quantity of metronidazole released at the same time intervals was tested by spectrophotometric method. Hydrogel consists of 99% water dispersion of Carbopol 971P and 1% glycerol characterized by the largest pharmaceutical bioavailability.