Mechanical, optical, and physicochemical properties of HPMC-based doxazosin mesylate orodispersible films

Abstract In this study, orodispersible films formed from hydroxypropyl methylcellulose (HPMC) E6 (2, 2.5, and 3%) and plasticizers ((glycerin (Gly), propylene glycol (PP), or polyethylene glycol (PEG)), containing doxazosin mesylate, were prepared by the solvent casting method and characterized. Design of experiments (DoE) was used as a statistical tool to facilitate the interpretation of the experimental data and allow the identification of optimal levels of factors for maximum formulation performance. Differential scanning calorimetry (DSC) curves and X-ray powder diffraction (XRPD) diffractograms showed doxazosin mesylate amorphization, probably due to complexation with the polymer (HPMC E6), and the glass transition temperature of the polymer was reduced by adding a plasticizer. Fourier transformed infrared (FTIR) spectroscopy results showed that the chemical structure of doxazosin mesylate was preserved when introduced into the polymer matrix, and the plasticizers, glycerin and PEG, affected the polymer matrix with high intensity. The addition of plasticizers increased the elongation at break and adhesiveness (Gly > PEG > PP), confirming the greater plasticizer effect of Gly observed in DSC and FTIR studies. Greater transparency was observed for the orodispersible films prepared using PP. The addition of citric acid as a pH modifier was fundamental for the release of doxazosin mesylate, and the desirability formulation had a release profile similar to that of the reference product

In vitro surface roughness of different glass ionomer cements indicated for ART restorations

Aim: The aim of this in vitro study was to evaluate the surface roughness of three glass ionomer cements (GICs) indicated for ART restorations. Methods: Ten cylindrical specimens of three commercial glass ionomers cements (Vidrion R - S.S. White, Maxxion R - FGM and Vitromolar DFL) were prepared (n=30) without surface finishing or protection. Twenty-four hours after preparation, the surface roughness measurements were obtained as the mean of three readings of the surface of each specimen by profilometry. The roughness values (Ra, ìm) were subjected to one-way ANOVA and Tukey’s test (p<0.05). Results: No statistically significant difference swere observed between Vidrion R (0.18 ± 0.05) and Vitromolar (0.21 ± 0.05), whereas Maxxion R presented significantly higher roughness values than those of the other materials. Conclusions: It may be concluded that characteristics of particle size and composition of the different GICs affected their surface roughness 24 h after preparation.

Estudo das alterações em esmalte de dentes decíduos após exposição a bebidas disponíveis no mercado / Study of the changes in the temporary teeth enamel after exposure to drinks available on the market

O objetivo deste estudo foi avaliar a morfologia e rugosidade superficial do esmalte de dentes decíduos antes e após exposição a cinco diferentes soluções, incluindo bebidas industrializadas, disponíveis no mercado nacional e rotineiramente consumidas por crianças (saliva artificial, Coca-Cola, suco Kapo (sabor morango), suco Del Valle Monsters (sabor pêssego) e Yakult). Aferiu-se o pH das mesmas e 50 caninos decíduos humanos foram distribuídos aleatoriamente em cinco grupos, a face vestibular de cada dente foi delimitada no seu longo eixo, uma parte foi imersa em 50 mL de solução (15 minutos) e lavada com água deionizada (15 segundos). Ambas as faces foram analisadas por meio de perfilômetro (FormTracer ? modelo SV? CS25). A análise estatística não mostrou diferença entre as faces (controle e tratada) e entre as bebidas avaliadas. A análise morfológica pela Microscopia Eletrônica de Varredura mostrou diferentes padrões de perda da estrutura dental, sugerindo maior alteração morfológica quanto maior acidez da bebida. Concluiu-seque as soluções demonstraram potencial erosivo, porém não houve diferenças estatísticas entre as faces dos dentes (controle e tratada) e entre os efeitos causados pelas bebidas na superfície dental.

The purpose of this study was to evaluate the morphology and surface texture of temporary teeth enamel before and after exposure to fi ve different solutions, including industrialized drinks, available in the national market and routinely consumed by children (artifi cial saliva, Coca-Cola,Kapo juice (strawberry fl avor), Del Valle Monsters juice (peach fl avor) and Yakult). The pH of these drinks was measured and fi fty human deciduous canines were randomly distributed intofi ve groups. The vestibular face of each tooth was delimited in its long axis, and part of it was immersed in 50 mL of solution for 15 minutes and rinsed with deionized water for 15 seconds.Both faces were analyzed through perfi lometer (FormTracer – model SV-CS25). The statistical analysis showed no differences between the faces (control and treated) and beverages evaluated. The morphological analysis by Scanning Electron Microscopy showed different dental structure loss patterns, suggesting greater morphological change in more acid beverages. So, it was concludedthat the solutions demonstrated erosive potential, but there were no statistical differences between the faces (control and treated) of human deciduous canines and the effects caused by drinks on the dental enamel surface.