Preparation and characterization of bioadhesive system containing hypericin for local photodynamic therapy.

Hypericin (Hyp) is a natural photoactive pigment utilized in the treatment of different types of cancer and antimicrobial inactivation using photodynamic therapy (PDT). Hyp is poorly soluble in water leading to problems of administration, getting close contact with the site, and bio-availability. Therefore, this study aimed to develop bioadhesive thermoresponsive system containing Hyp for local PDT. Carbomer 934P, poloxamer 407, and Hyp were used to prepare the thermoresponsive bioadhesive formulations. They were characterized for sol-gel transition temperature, mechanical, mucoadhesive, rheological (continuous flow and oscillatory) and dielectric properties, syringeability, in vitro Hyp release kinetics, ex vivo permeability, and photodynamic activity. The formulations displayed suitable gelation temperature and rheological characteristics. The compressional, mechanical and mucoadhesive properties, as well the syringeability showed the easiness of administration and the permanence of the system adhered to the mucosa or skin. The dielectric analysis helped to understand the Hyp availability, and its release presented an anomalous behavior. The system did not permeate the pig skin nor rat intestine and showed good biological photodynamic activity. Therefore, data obtained from the bioadhesive system indicate a potentially useful role as a platform for local hypericin delivery in PDT, suggesting it is worthy of in vivo evaluation.

Screening and In Vitro Evaluation of Mucoadhesive Thermoresponsive System Containing Methylene Blue for Local Photodynamic Therapy of Colorectal Cancer.

PURPOSE: Photodynamic therapy (PDT) with methylene blue (MB) constitutes a potentially useful modality for colorectal cancer treatment. The limitations of the formulations containing MB are problems of administration and the inability to get the closeness contact at the site during the appropriate residence time. Present study aimed to develop and characterize mucoadhesive thermoresponsive system containing MB designed as platform for colorectal cancer therapy. METHODS: Formulations composed of different amounts of poloxamer 407 (Polox), Carbopol 934P (Carb), and MB were developed and characterized as rheological, compressional, mucoadhesive and syringeability properties, toxicity, photodynamic action, in vitro MB release profile, and ex vivo MB intestinal permeation. RESULTS: The different compositions resulted in formulations with distinctive macroscopic characteristics and wide range of gelation temperatures. The compressional flow, mucoadhesive, syringeability, and rheological properties were significantly influenced by temperature and/or composition. The MB release from formulation was governed by anomalous transport. In addition, it was observed that MB permeated the intestinal membrane; the formulation possesses photodynamic activity and low toxicity. CONCLUSIONS: The data obtained from the system composed of 20% Polox, 0.15% Carb, and 0.25% MB indicated a potentially functional role in PDT of the colorectal cancer and suggest it is worthy of clinical evaluation.

Photodynamic Inactivation Mediated by Erythrosine and its Derivatives on Foodborne Pathogens and Spoilage Bacteria.

The purpose of the present study was to evaluate the efficacy of photodynamic inactivation (PDI) mediated by erythrosine (ERY) and its ester derivatives erythrosine methyl ester (ERYMET) and erythrosine butyl ester (ERYBUT) on foodborne pathogens and spoilage bacteria. We evaluated Staphylococcus aureus ATCC 25923, Aeromonas hydrophila ATCC 7966, Salmonella enterica serotype Typhimurium ATCC 14028, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853. The toxicity of all of the compounds was assessed in VERO cells. PDI mediated by ERY and its derivatives combined with a light-emitting diode was performed at different concentrations and exposure times. S. aureus was more photosensitive than Gram-negative bacteria to ERY, ERYMET, and ERYBUT. The ERY-mediated PDI of S. aureus induced a significant reduction of 4.0 log CFU/ml at a light dose of 40 J/cm(2). ERYMET and ERYBUT at lower light doses than ERY completely eradicated S. aureus. When photoirradiated with ERY at light doses of 156 and 234 J/cm(2), A. hydrophila was completely eradicated. ERYBUT was more efficient in the PDI of A. hydrophila than ERYMET, even at 1 x 10(-5) M and lower light doses. Salmonella Typhimurium, E. coli, and P. aeruginosa required higher concentrations of photosensitizers to reduce cell survival. ERYBUT and ERY may be promising photosensitizing agents against A. hydrophila and S. aureus. They were effective at reducing bacterial counts at nontoxic concentrations. The photoinactivation rate of the evaluated bacteria decreased in the following order: S. aureus > A. hydrophila > E. coli > S. Typhimurium > P. aeruginosa.

Avaliação da atividade antimicrobiana de antissépticos e desinfetantes utilizados em um serviço público de saúde / Evaluation of antimicrobial activity antiseptics and disinfectants used in a public health service / Evaluación de la actividad antimicrobiana de los antisépticos y desinfectantes utilizados en un servicio de salud pública

O estudo teve como objetivo determinar in vitro a atividade antimicrobiana de antissépticos e desinfetantes utilizados no serviço de atenção primária à saúde de uma cidade do norte do Paraná, utilizando microrganismos padronizados pelo Instituto Nacional de Controle de Qualidade em Saúde da Fundação Oswaldo Cruz. Para tanto, foram realizadas análises da atividade antimicrobiana e da estabilidade química de três diferentes antissépticos e um desinfetante utilizados no serviço de atenção primária à saúde. A partir das análises realizadas no primeiro, sétimo, décimo quarto e vigésimo primeiro dias, após a abertura dos frascos, verificou-se que as amostras mantiveram sua atividade antimicrobiana in vitro em relação às cepas padronizadas, evidenciadas pela ausência de crescimento de unidades formadoras de colônias e estabilidade química dos princípios ativos dos antissépticos. O estudo permitiu verificar a eficácia das amostras frente a análises microbiológicas in vitro utilizando microrganismos padronizados.

The study aimed to determine the in vitro antimicrobial activity of antiseptics and disinfectant used in the care service primary health of a city in northern Paraná, using microorganisms standardized by the National Institute of Quality Control in Health, Oswaldo Cruz Foundation. For this purpose, we performed tests of antimicrobial activity and chemical stability of three samples of antiseptic and one disinfectant used in the service. From the analysis performed the first, seventh, fourteenth and twenty-first day after the opening of the bottles, it was found that the samples retained their activity in vitro antimicrobial regarding standardized strains, as evidenced by the absence of growth of colony-forming units and maintaining the chemical stability. The study demonstrated the efficacy of the samples against analysis microbiological in vitro using standardized microorganisms.

El objetivo del estudio fue determinar la actividad antimicrobiana in vitro de los antisépticos y desinfectante utilizados en el servicio de atención primaria de salud en una ciudad en el norte de Paraná, utilizando microorganismos estandarizado por el Instituto Nacional de Control de Calidad en Salud, Fundación Oswaldo Cruz. Con este fin, se realizó un análisis actividad antimicrobiana y la estabilidad química de tres muestras de un antiséptico y desinfectante utilizado en el servicio. Del análisis realizado en el primer, siete, catorce y veintiuno días, después de la apertura de las botellas, se encontró que las muestras mantuvieron su actividad antimicrobiana in vitro frente a cepas estándar, evidencia la ausencia de crecimiento de unidades formadoras de colonias y el mantenimiento de la estabilidad química. El estudio demostró la eficacia de las muestras en contra de organismos microbiológicos utilizando estandarizados in vitro.

[Evaluation of antimicrobial activity antiseptics and disinfectants used in a public health service]. / Avaliação da atividade antimicrobiana de antissépticos e desinfetantes utilizados em um serviço público de saúde.

The study aimed to determine the in vitro antimicrobial activity of antiseptics and disinfectant used in the care service primary health of a city in northern Paraná, using microorganisms standardized by the National Institute of Quality Control in Health, Oswaldo Cruz Foundation. For this purpose, we performed tests of antimicrobial activity and chemical stability of three samples of antiseptic and one disinfectant used in the service. From the analysis performed the first, seventh, fourteenth and twenty-first day after the opening of the bottles, it was found that the samples retained their activity in vitro antimicrobial regarding standardized strains, as evidenced by the absence of growth of colony-forming units and maintaining the chemical stability. The study demonstrated the efficacy of the samples against analysis microbiological in vitro using standardized microorganisms.