Tag Archives: in vitro

In Vitro Interactions of Diclofenac with Several Types of Food

Ibolya Fülöp, Mircea Dumitru Croitoru, Andrea Vajda, Irén Jakab, Erzsébet Fogarasi

University of Medicine and Pharmacy of Tirgu Mures, Romania

DOI: 10.1515/amma-2016-0030

Objective: The aim of this study was to evaluate how the membrane transport of diclofenac on presence of different types of food is modified.
Methods: The interaction of diclofenac, as a pure substance and solid dispersions of the active ingredient, with different types of foods was investigated in vitro condition using a modified Franz diffusion cell.
Results: The amount of diclofenac transported through a lipophilic membrane was reduced by the presence of foodstuffs in artificial gastric juice and intestinal juice also, both in the case of the pure substance and solid dispersions also. The only exception was the case of milk in artificial gastric juice, when the amount of diclofenac in the receiving compartment increased about 2-fold compared to the fasted conditions simulating media. In the case of the solid dispersions of diclofenac the membrane transport increased in all cases compared to the pure substance, but was also reduced by the foods.
Conclusions: It was concluded that, the presence of different foodstuffs can influence the membrane transport of diclofenac – by inhibiting its solubility – and these differences observed in vitro can lead to modifications in the in vivo pharmacokinetic parameters. The lowest difference in diclofenac membrane transport was observed in the case of diclofenac:PEG 6000 solid dispersion prepared in 1:5 mass ratio.

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Quantifying Human Enamel Erosion Caused By Freshly Squeezed Juices

Borş Andreea1, Fazakas Zita2, Molnar-Varlam Cristina1, Cămărăşan Alina1, Mucenic Simona1, Kerekes-
Máthé Bernadette¹, Székely Melinda1

1 Department of Morphology of Teeth and Dental Arches; Technology of Dental Prosthesis and Dental Materials, Faculty of Dentistry, University of Medicine and Pharmacy, Târgu-Mureş
2 Department of Biochemistry, University of Medicine and Pharmacy, Târgu-Mureş

Aims: The present in vitro study intended to investigate minimal erosive effects of different freshly squeezed fruit juices on human enamel during short time incubation by determination of calcium and phosphate dissolution.
Material and methods: Healthy adult human molars and premolars were cut in 160 blocks (5 mm x 6 mm x 2 mm) and divided randomly in sixteen groups of 10 samples each (n = 10). Each group was assigned for immersion at 37 oC in 5 ml juice, for different spot times 3, 6, 9 and 12 minutes, respectively. The freshly squeezed juices analyzed were orange juice, apple juice, orange mixed with carrot juice (1:1) and apple mixed with carrot juice (1:1). Amount of titratable acid and pH was measured for the tested solutions. Calcium and phosphate release were determined photometrically using VIS-UV/VIS spectrophotometer. ANOVA test compared the data generated (p < 0.05).
Results: The apple juice showing the lowest pH and a high value for buffering capacity had the most pronounced erosive effect. The orange juice was less erosive (p < 0.001). The least erosive was the orange mixed with carrots (1:1) (p < 0.001), which has the highest pH. The enamel demineralization increased when prolonging the immersion time (p < 0.0001).
Conclusions: All freshly squeezed juices caused the dissolution of calcium and phosphate in human enamel. Erosive capacity is mainly determined by pH and to a lesser extent by the buffering capacity. The amount of demineralization is directly correlated with the exposure time. Absorption spectroscopy allows detection of very small mineral loss using standardised human enamel samples.

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The Behaviour of Composites, Glass Ionomers and Compomers in Erosive Conditions – In Vitro Study

Borş Andreea, Molnar-Varlam Cristina, Székely Melinda

Department of Morphology of Teeth and Dental Arches; Technology of Dental Prosthesis and Dental Materials, Faculty of Dental Medicine, University of Medicine and Pharmacy, Tîrgu Mureş

DOI: 10.2478/amma-2014-0042

Objective: The aim of this in vitro study was to evaluate the influence of erosive conditions on the wear resistance of aesthetic direct restorative materials.
Methods: Six dental filling materials were tested: two composites (Filtek Z550 and X-tra fil), two compomers (Dyract Extra and Twinky Star) and two glass ionomers (Ketac Molar and Fuji II LC). Twenty disks (10mm×2mm) of each material were prepared (n=120) and kept in artificial saliva at 37˚C for 24 hours. Specimens were cycled in acidic soft drink (Coca-Cola) 5×/day, for 5’, over 30 days. Initial surface roughness ISR (Ra-μm) and final surface roughness FSR were measured using a profilometer. The wear rate was calculated as difference of final minus the initial roughness (ΔSR=FSR-ISR). For statistical analysis t-test and one-way ANOVA test were used by GraphPad Prism version 5.03 statistical software. The level of significance was set at p<0.05.
Results: The erosive wear rates (mean±SD, µm) after exposure to acidic beverage were: 0.30±0.03 (Ketac Molar), 0.28±0.04 (Fuji II LC), 0.27±0.00 (Filtek Z550), 0.23±0.01 (X-tra fil), 0.20±0.00 (Twinky Star) and 0.14±0.01 Dyract Extra, respectively. There were significant differences between the tested materials (p<0.05).
Conclusions: Dental filling materials had different behaviour under the same erosive condition, however all investigated aesthetic restorative materials showed surface degradation. These findings suggest that erosive wear resistance of tooth coloured restoratives could influence their longevity in intraoral acidic conditions. Acknowledgements: The study was supported by the Internal Research Grant no. 5/30.01.2013 of the University of Medicine and Pharmacy of Tîrgu Mureş.

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