Mechanical and biological characterization of resin-modified glass-ionomer cement containing doxycycline hyclate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Quantification of Doxycycline Hyclate in Tablets by HPLC-UV Method

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Increasing Doxycycline Hyclate Photostability by Complexation with beta-Cyclodextrin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Development and validation of a stability-indicative turbidimetric assay to determine the potency of doxycycline hyclate in tablets

The doxycycline (DOX) is a broad-spectrum antibiotic used in several countries. This drug is part of the list of medicines to the SUS (Unified Health System), a model of health care in Brazil. This study describes the development and validation of a microbiological assay, applying the turbidimetric method for the determination of DOX, as well as the evaluation of the ability of the method in determining the stability of DOX in tablets against acidic and basic hydrolysis, photolytic and oxidative degradations, using Escherichia coli ATCC 10536 as micro-organism test and 3×3 parallel line assay design, with nine tubes for each assay, as recommended by the Brazilian Pharmacopoeia. The developed and validated method showed excellent results of linearity, selectivity, precision, accuracy and robustness. The assay is based on the inhibitory effect of DOX using Escherichia coli ATCC 10536. The results of the assay were treated by analysis of variance and were found to be linear (r= 0.9986) in the range from 4.0 to 9.0μg/mL, precise (repeatability R.S.D.= 0.99 and intermediate precision was confirmed by statistical analysis the mean values obtained from analysis by different analysts) and exact (97.73%). DOX solution exposed to direct UV light, alkaline and acid hydrolysis and hydrogen peroxide causing oxidation were used to evaluate the specificity of the bioassay. Comparison of bioassay and liquid chromatography showed differences in results between methodologies. The results showed that the bioassay is valid, simple and useful alternative methodology for DOX determination in routine quality control.

Doxycycline hyclate: a review of properties, applications and analytical methods

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Protonation Pattern, Tautomerism, Conformerism, and Physicochemical Analysis in New Crystal Forms of the Antibiotic Doxycycline

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise químico-farmacêutica de hiclato de doxiciclina em comprimidos e de seu complexo de inclusão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ehrlichia canis (Jaboticabal strain) induces the expression of TNF-alpha in leukocytes and splenocytes of experimentally infected dogs

Canine ehrlichiosis is caused by the bacterium Ehrlichia canis and is characterized by a systemic febrile disease of unknown pathogenesis. This study evaluated the expression of cytokines TNF-alpha, IL-10, IFN-gamma, in splenic cells and blood leukocytes during the acute phase of ehrlichiosis and after treatment with doxycycline hyclate in dogs experimentally infected with the E. canis Jaboticabal strain. The study results showed a significant expression of TNF-alpha 18 days post-inoculation, reducing by approximately 70% after treatment. There was a unique peak of expression of IL-10 and IFN-gamma 18 and 30 days post-inoculation, respectively. This study suggests that TNF-alpha plays a role in the pathogenesis of the acute phase of canine ehrlichiosis and that treatment with doxycycline hyclate reduces the systemic effects of this cytokine, possibly by reducing or eliminating parasitemia.

Avaliação adrenocortical, tireoideana e do estresse oxidativo de cães naturalmente infectados por Ehrlichia canis

Pós-graduação em Medicina Veterinária - FCAV

Flow-injection spectrophotometric determination of tetracycline and doxycycline in pharmaceutical formulations using chloramine-T as oxidizing agent

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A simple spectrophotometry method for the determination of tetracycline and doxycycline in pharmaceutical formulations using chloramine-T

A simple, rapid, accurate and inexpensive spectrophotometric method for the determination of tetracycline and doxycycline has been developed. The method is based on the reaction between these drugs and chloramine-T in alkaline medium producing red color products with absorbance maximum at the λ=535 and 525 nm for the tetracycline and doxycycline, respectively. The best conditions for the reactions have been found using multivariate method. Beer's law is obeyed in a concentration ranges 1. 03 x 10 -5 to 3. 61 x 10 4mol L -1 and 1. 75 x 10 -5 to 3. 48 x 10 4mol L -1 for the tetracycline and doxycycline, respectively. The quantification limits were 5. 63 x 10 -6 mol L -1 and 7. 12 x 10 -7 mol L -1 for the tetracycline and doxycycline, respectively. The proposed method was successfully applied to the determination of these drugs in pharmaceutical formulations and the results obtained were in good agreement with those obtained by the comparative method at the 95% confidence level.

Doxycycline-Encapsulated Nanotube-Modified Dentin Adhesives

This article presents details of fabrication, biological activity (i.e., anti-matrix metalloproteinase [anti-MMP] inhibition), cytocompatibility, and bonding characteristics to dentin of a unique doxycycline (DOX)-encapsulated halloysite nanotube (HNT)-modified adhesive. We tested the hypothesis that the release of DOX from the DOX-encapsulated nanotube-modified adhesive can effectively inhibit MMP activity. We incorporated nanotubes, encapsulated or not with DOX, into the adhesive resin of a commercially available bonding system (Scotchbond Multi-Purpose [SBMP]). The following groups were tested: unmodified SBMP (control), SBMP with nanotubes (HNT), and DOX-encapsulated nanotube-modified adhesive (HNT+DOX). Changes in degree of conversion (DC) and microtensile bond strength were evaluated. Cytotoxicity was examined on human dental pulp stem cells (hDPSCs). To prove the successful encapsulation of DOX within the adhesivesbut, more important, to support the hypothesis that the HNT+DOX adhesive would release DOX at subantimicrobial levelswe tested the antimicrobial activity of synthesized adhesives and the DOX-containing eluates against Streptococcus mutans through agar diffusion assays. Anti-MMP properties were assessed via -casein cleavage assays. Increasing curing times (10, 20, 40 sec) led to increased DC values. There were no statistically significant differences (p > .05) in DC within each increasing curing time between the modified adhesives compared to SBMP. No statistically significant differences in microtensile bond strength were noted. None of the adhesives eluates were cytotoxic to the human dental pulp stem cells. A significant growth inhibition of S. mutans by direct contact illustrates successful encapsulation of DOX into the experimental adhesive. More important, DOX-containing eluates promoted inhibition of MMP-1 activity when compared to the control. Collectively, our findings provide a solid background for further testing of encapsulated MMP inhibitors into the synthesis of therapeutic adhesives that may enhance the longevity of hybrid layers and the overall clinical performance of adhesively bonded resin composite restorations.

Down-regulation of protease activated receptor 2, interleukin-17 and other pro-inflammatory genes by subantimicrobial doxycycline dose in a rat periodontitis model

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Prevalence of Methicillin-Resistant Staphylococci on a Farm: Staff can Harbour MRS When Animals do Not

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of TNF-alpha blockers on the oral prevalence of opportunistic microorganisms in ankylosing spondylitis patients

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)