Influence of additives on swelling and mucoadhesion properties of glyceryl monooleate liquid crystals

Abstract Liquid crystalline systems of glyceryl monooleate/water are used as drug delivery systems due to their complex structure that controls drug diffusion. Mucoadhesive properties of glyceryl monooleate suggest it can be used for buccal delivery. Using additives is a strategy to modify physical and chemical properties of liquid crystalline systems and optimize their performance as a drug delivery system. However, the presence of additives can significantly alter properties such as phase behavior, swelling and mucoadhesion. Our aim is to investigate the influence of additives on swelling and mucoadhesion of glyceryl monooleate-based liquid crystals, intending them to be used as buccal drug delivery systems. The systems were characterized regarding their mesophases, swelling rate, and mucoadhesion. All the systems studied were able to absorb water and presented mucoadhesion, which is interesting for the development of buccal drug delivery systems. Additives induced phase transitions and affected the swelling performance, while mucoadhesive properties were poorly affected. Propylene glycol increased water uptake, while oleic acid induced the phase transition to the hexagonal phase and reduced the swelling rate. The association of oleic acid (5%) and propylene glycol (10%) resulted in a cubic phase system with strong mucoadhesive properties that can be a potential drug carrier for buccal delivery.

Green Synthesis, Characterization and Antimicrobial Evaluation of Silver Nanoparticles for an Intracanal Dressing.

Green chemistry has been applied in different areas due to the growing demands for renewable processes and one of them is nanotechnology. The aim of this study was to characterize a formulation containing silver nanoparticles (AgNPs) produced by a green synthesis and to evaluate its antimicrobial activity. The formulation will be used as an intracanal dressing exploiting the AgNPs' antimicrobial properties, which are crucial to prevent infections and bacterial reinfections that can compromise endodontic treatments. In the green synthesis, silver nitrate was employed as the precursor salt, maltose as a reducing agent, and gelatin as a stabilizing agent. The formulation was prepared mixing 50 % of a liquid containing the AgNPs and 50 % of hydroxyethylcellulose gel at 1.5 % with proper evaluation of the process inherent parameters. Techniques such as molecular absorption spectrometry and dynamic light scattering were used in characterization step. The antimicrobial activity of the AgNPs against Escherichia coli ATCC 25922, Enterococcus faecalis NCTC 775, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Streptococcus mutans ATCC 25175 was verified according to National Comittee for Clinical Laboratory Standards (NCCLS) by determining minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The obtained results indicated the formulation containing AgNPs produced by a green synthesis was properly characterized by the selected techniques. Furthermore, the formulation assessment proved that it is suitable for the proposal as well as it has potential to be used as an intracanal dressing since presented antimicrobial activity against all bacterial strains evaluated.

Green synthesis, characterization and antimicrobial evaluation of silver nanoparticles for an intracanal dressing

Abstract Green chemistry has been applied in different areas due to the growing demands for renewable processes and one of them is nanotechnology. The aim of this study was to characterize a formulation containing silver nanoparticles (AgNPs) produced by a green synthesis and to evaluate its antimicrobial activity. The formulation will be used as an intracanal dressing exploiting the AgNPs' antimicrobial properties, which are crucial to prevent infections and bacterial reinfections that can compromise endodontic treatments. In the green synthesis, silver nitrate was employed as the precursor salt, maltose as a reducing agent, and gelatin as a stabilizing agent. The formulation was prepared mixing 50 % of a liquid containing the AgNPs and 50 % of hydroxyethylcellulose gel at 1.5 % with proper evaluation of the process inherent parameters. Techniques such as molecular absorption spectrometry and dynamic light scattering were used in characterization step. The antimicrobial activity of the AgNPs against Escherichia coli ATCC 25922, Enterococcus faecalis NCTC 775, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Streptococcus mutans ATCC 25175 was verified according to National Comittee for Clinical Laboratory Standards (NCCLS) by determining minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The obtained results indicated the formulation containing AgNPs produced by a green synthesis was properly characterized by the selected techniques. Furthermore, the formulation assessment proved that it is suitable for the proposal as well as it has potential to be used as an intracanal dressing since presented antimicrobial activity against all bacterial strains evaluated.

Resumo A química verde tem sido aplicada em diferentes áreas devido à crescente demanda por processos renováveis e uma delas é a nanotecnologia. O objetivo deste estudo foi caracterizar uma formulação contendo nanopartículas de prata (AgNPs) produzidas por meio de síntese verde e avaliar sua atividade antimicrobiana. A formulação será usada como curativo intracanal explorando as propriedades antimicrobianas das AgNPs que são cruciais para prevenir infecções e reinfecções bacterianas que podem comprometer os tratamentos endodônticos. Na síntese verde, nitrato de prata foi empregado como sal precursor, maltose como agente redutor e gelatina como agente estabilizador. A formulação foi preparada misturando-se 50% do líquido contendo as AgNPs e 50% de gel de hidroxietilcelulose a 1,5% com avaliação adequada dos parâmetros inerentes ao processo. Técnicas como espectrometria de absorção molecular e espalhamento dinâmico de luz foram usadas na etapa de caracterização. A atividade antimicrobiana das AgNPs contra Escherichia coli ATCC 25922, Enterococcus faecalis NCTC 775, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 e Streptococcus mutans ATCC 25175 foi verificada de acordo com o National Comittee for Clinical Laboratory Standards (NCCLS), determinando-se a concentração inibitória mínima (MIC) e a concentração bactericida mínima (MBC). Os resultados obtidos indicaram que a formulação contendo AgNPs produzidas por meio de síntese verde foi devidamente caracterizada pelas técnicas selecionadas. Além disso, a avaliação da formulação provou que ela é adequada para a proposta, bem como tem potencial para ser utilizada como curativo intracanal já que apresentou atividade antimicrobiana contra todas as cepas bacterianas avaliadas.

Liquid Crystalline Systems Based on Glyceryl Monooleate and Penetration Enhancers for Skin Delivery of Celecoxib: Characterization, In Vitro Drug Release, and In Vivo Studies.

Celecoxib (CXB) is a widely used anti-inflammatory drug that also acts as a chemopreventive agent against several types of cancer, including skin cancer. As the long-term oral administration of CXB has been associated with severe side effects, the skin delivery of this drug represents a promising alternative for the treatment of skin inflammatory conditions and chemoprevention of skin cancer. We prepared and characterized liquid crystalline systems based on glyceryl monooleate and water containing penetration enhancers which were primarily designed to promote skin delivery of CXB. Analysis of their phase behavior revealed the formation of cubic and hexagonal phases depending on the systems' composition. The systems' structure and composition markedly affected the in vitro CXB release profile. Oleic acid reduced CXB release rate, but association oleic acid/propylene glycol increased the drug release rate. The developed systems significantly reduced inflammation in an aerosil-induced rat paw edema model. The systems' composition and liquid crystalline structure influenced their anti-inflammatory potency. Cubic phase systems containing oleic acid/propylene glycol association reduced edema in a sustained manner, indicating that they modulate CXB release and permeation. Our findings demonstrate that the developed liquid crystalline systems are potential carriers for the skin delivery of CXB.

In Vitro and In Vivo Evaluation of DMSO and Azone as Penetration Enhancers for Cutaneous Application of Celecoxib.

BACKGROUND: Celecoxib (CXB) has been explored as an anti-inflammatory or chemopreventive drug for topical treatment of skin diseases and cancer. OBJECTIVE: The main aim of this work was to investigate the potential of dimethylsufoxide (DMSO) and Azone (AZ) as penetration enhancers (P.Es) for topical delivery of CXB. METHOD: The in vitro studies, drug release, skin permeability and potential cytotoxicity/genotoxicity were carried out with formulations containing or not DMSO or AZ (5% and 10%). Skin irritation in rabbits and topical anti-inflammatory activity in mice were assayed in vivo. RESULTS: Skin permeation was minimal while higher retention in stratum corneum (SC) and epidermis plus dermis was found (28.0 and 3-fold respectively) from 10.0% AZ compared to the control indicating a localized CXB effect. CXB associated to 5% or 10% DMSO has shown high drug permeation through skin with low retention. Associations of CXB with both enhancers were not cytotoxic or genotoxic, suggesting safety for cutaneous application. In vivo skin irritation assays of all formulations indicated mild irritation effects and, thus, possible use for longer periods. In vivo anti-inflammatory tests showed that ear edema could be inhibited by CXB associated with 5.0% DMSO (53.0%) or 10.0% AZ (40.0%). These inhibition values were almost 2-fold higher when compared to a commercial formula. CONCLUSION: Although DMSO- associated CXB is an efficient edema inhibitor its high skin permeation suggests risks of systemic effects, whereas association to 10% AZ may improve topical delivery of the drug with good anti-inflammatory activity and no cytotoxic/genotoxic or significant skin irritation effects.

Effect of Liquid Crystalline Systems Containing Antimicrobial Compounds on Infectious Skin Bacteria.

This study aimed (i) to prepare liquid crystalline systems (LCS) of glyceryl monooleate (GMO) and water containing antibacterial compounds and (ii) to evaluate their potential as drug delivery systems for topical treatment of bacterial infections. Therefore, LCS containing CPC (cetylpyridinium chloride) (LCS/CPC) and PHMB (poly(hexamethylene biguanide) hydrochloride) (LCS/PHMB) were prepared and the liquid crystalline phases were identified by polarizing light microscopy 24 h and 7 days after preparation. The in vitro drug release profile and in vitro antibacterial activity of the systems were assessed using the double layer agar diffusion method against Staphylococcus aureus, methicillin-resistant S. aureus, Staphylococcus epidermidis, Escherichia coli, and Enterococcus faecalis. The interaction between GMO and the drugs was evaluated by a drug absorption study. Stable liquid crystalline systems containing CPC and PHMB were obtained. LCS/PHMB decreased the PHMB release rate and exerted strong antibacterial activity against all the investigated bacteria. In contrast, CPC interacted with GMO so strongly that it became attached to the system; the amount released was not sufficient to exert antibacterial activity. Therefore, the studied liquid crystalline systems were suitable to deliver PHMB, but not CPC. Accordingly, it was demonstrated that GMO interacts with each drug differently, which may interfere in the final efficiency of GMO/water LCS.

Mucoadhesive system formed by liquid crystals for buccal administration of poly(hexamethylene biguanide) hydrochloride.

Antimicrobial approaches are valuable in controlling the development of buccal diseases, but some antibacterial agents have a short duration of activity. Therefore, the development of prolonged delivery systems would be advantageous. Liquid crystalline systems comprising monoolein (GMO)/water have been considered to be a potential vehicle to deliver drugs to the buccal mucosa because of the phase properties that allow for controlled drug release as well as its mucoadhesive properties. Therefore, the aim of this study was to develop a GMO/water system for the slow release of poly(hexamethylene biguanide) hydrochloride (PHMB) on the buccal mucosa and test the properties of this system with regard to swelling, release profile, antimicrobial activity, and strength of mucoadhesion, with the overall goal of treating buccal infections. The tested systems were capable of modulating drug release, which is controlled by diffusion of the drug throughout the system. Furthermore, PHMB appeared to improve the mucoadhesive properties of the system and may synergistically act with the drug to promote antimicrobial activity against S. mutas and C. albicans, indicating that liquid crystals may be suitable for the administration of PHMB on the buccal mucosa. Therefore, this system could be proposed as a novel system for mucoadhesive drug delivery.

Development of intracanal formulation containing silver nanoparticles.

This study aimed to synthetize, characterize and evaluate the antimicrobial properties of silver nanoparticles to be used in the development of a root intracanal formulation. Silver nanoparticles (AgNPs) were obtained by reduction of silver nitrate with sodium borohydride and characterized by UV-Visible spectrophotometry, scanning electron microscopy (SEM) and dynamic light scattering (DLS). The antimicrobial activity of nanoparticle formulation was evaluated by determinations of the minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against different bacterial species by the microdilution method, according to recommendations of the Clinical and Laboratory Standards Institute (CLSI). Three potential vehicles, hydroxyethylcellulose, Carbomer and polyethylene glycol were tested as carriers for formulations containing AgNPs. The efficiency of the synthesis method chosen to produce AgNPs was demonstrated by four characterization techniques. The nanoparticles showed antibacterial activity against all species tested. Incorporation of AgNPs into all experimental vehicles produced stable formulations but the one in hydroxyethylcellulose presented better physical proprieties. The results indicate that silver nanoparticles are potential antiseptic agents to be used in root canals and incorporation in adequate vehicles may favor a broader application.

Liquid crystalline systems for transdermal delivery of celecoxib: in vitro drug release and skin permeation studies.

Liquid crystalline systems of monoolein/water could be a promising approach for the delivery of celecoxib (CXB) to the skin because these systems can sustain drug release, improve drug penetration into the skin layers and minimize side effects. This study evaluated the potential of these systems for the delivery of CXB into the skin based on in vitro drug release and skin permeation studies. The amount of CXB that permeated into and/or was retained in the skin was assayed using an HPLC method. Polarizing light microscopy studies showed that liquid crystalline systems of monoolein/water were formed in the presence of CXB, without any changes in the mesophases. The liquid crystalline systems decreased drug release when compared to control solution. Drug release was independent of the initial water content of the systems and CXB was released from cubic phase systems, irrespective of the initial water content. The systems released the CXB following zero-order release kinetics. In vitro drug permeation studies showed that cubic phase systems allowed drug permeation and retention in the skin layers. Cubic phase systems of monoolein/water may be promising vehicles for the delivery of CXB in/through the skin because it improved CXB skin permeation compared with the control solution.

In vitro and in vivo influence of penetration enhancers in the topical application of celecoxib.

OBJECTIVE: We investigated the potential effects of oleic acid (OA) and glycerol monooleate (GMO) on the skin delivery of CXB. METHODS: The influence of both OA and GMO (5.0% or 10.0%) on the in vitro skin permeability of CXB (2.0%) was evaluated using propylene glycol (PG) as a vehicle. Also the in vitro potential cytotoxicity and genotoxicity and in vivo assays (skin irritation in rabbits and topical anti-inflammatory activity by in mice) were conducted. RESULTS: As expected, the amount of CXB that permeated through the skin was minimal, but drug retention on the viable skin (epidermis plus dermis) was higher in association with treatment with 5.0% OA or GMO compared to the control treatment, meaning that there was a localized effect of CXB in the skin. No formulation presented cytotoxic or genotoxic potential, suggesting safety for cutaneous application. In vivo skin irritation assays indicated that no formulation was irritating to the skin becomes its use possible for a prolonged time. In vivo anti-inflammatory experiments indicated that both edema and protein extravasation were inhibited with a maximum % inhibition of 53.5.0% and 61.0% for 5.0 % GMO, respectively, and 48.0% and 35.5% for 5.0% OA, respectively. Such formulations were able to inhibit around twofold the percentage of ear edema in mice compared to a commercial product reference diclofenac commercial formula. CONCLUSION: There is no topical formulation currently available that contains both CXB and 5.0% GMO or OA, suggesting them as potential adjuvants that improve the skin delivery of CXB.

Development of Intracanal Formulation Containing Silver Nanoparticles

This study aimed to synthetize, characterize and evaluate the antimicrobial properties of silver nanoparticles to be used in the development of a root intracanal formulation. Silver nanoparticles (AgNPs) were obtained by reduction of silver nitrate with sodium borohydride and characterized by UV-Visible spectrophotometry, scanning electron microscopy (SEM) and dynamic light scattering (DLS). The antimicrobial activity of nanoparticle formulation was evaluated by determinations of the minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against different bacterial species by the microdilution method, according to recommendations of the Clinical and Laboratory Standards Institute (CLSI). Three potential vehicles, hydroxyethylcellulose, Carbomer and polyethylene glycol were tested as carriers for formulations containing AgNPs. The efficiency of the synthesis method chosen to produce AgNPs was demonstrated by four characterization techniques. The nanoparticles showed antibacterial activity against all species tested. Incorporation of AgNPs into all experimental vehicles produced stable formulations but the one in hydroxyethylcellulose presented better physical proprieties. The results indicate that silver nanoparticles are potential antiseptic agents to be used in root canals and incorporation in adequate vehicles may favor a broader application.

O presente estudo teve como objetivo sintetizar, caracterizar e avaliar as propriedades antimicrobianas de nanopartículas de prata visando o desenvolvimento de uma formulação intracanal. As nanopartículas de prata (AGNPS) foram obtidas pela redução de nitrato de prata com borohidreto de sódio e caracterizados por espectrofotometria UV-Visível, microscopia eletrônica de varredura (MEV) e espalhamento de dinâmico de luz (DLS). A atividade antimicrobiana da formulação de nanopartículas foi avaliada por meio das determinações da concentração inibitória mínima (CIM) e a concentração bactericida mínima (CBM) contra diferentes espécies de bactérias pelo método de microdiluição, de acordo com recomendações do Clinical and Laboratory standards Institute (CLSI). Três potenciais veículos, hidroxietilcelulose, carbómero e polietileno glicol foram testados como veículos para as formulações de AGNPS. A eficiência do método de síntese escolhido para produzir AGNPS foi demonstrada por quatro técnicas de caracterização. As nanopartículas apresentaram atividade antibacteriana contra todas as espécies bacterianas testadas. A incorporação de AGNPS em todos os veículos experimentais produziram formulações estáveis, porém, quando utilizado a hidroxietilcelulose foram obtidos melhores propriedades físicas. Os resultados indicam que as nanopartículas de prata são potenciais agentes anti-sépticos para serem usados na terapia endodôntica e a incorporação em veículos adequados pode favorecer uma aplicação mais ampla.

Caracterização do intumescimento de sistemas líquido-cristalinos de fase lamelar de monoleína e água contendo polihexametilenobiguanida / Characterization of swelling of lamellar phases of monoolein and water containing polyhexamethylenebiguanide

A monoleína é um lipídeo polar capaz de absorver água e formar sistemas líquido-cristalinos, os quais são utilizados como sistemas de liberação para administração de vários fármacos. Neste estudo foi avaliado o potencial de sistemas de fase lamelar constituídos por monoleína e água para veicular polihexametilenobiguanida (PHMB). A formação dos sistemas líquido-cristalinos foi caracterizada por microscopia de luz polarizada. Estudos de intumescimento foram realizados gravimetricamente em várias condições avaliando-se os efeitos de parâmetros como pH, força iônica e temperatura do meio de imersão. O processo de intumescimento foi caracterizado através da obtenção dos perfis de intumescimento e análise de sua cinética, além da determinação da capacidade máxima de intumescimento dos sistemas. Os sistemas de fase lamelar foram obtidos em presença de PHMB, os quais absorveram água rapidamente de acordo com cinética de segunda ordem e sofreram transição de fase, formando a fase cúbica. O intumescimento dos sistemas não foi influenciado pela presença do fármaco nos vários meios de imersão estudados, exceto pela imersão em meio ácido, no qual a presença do PHMB aumentou a captação de água. O intumescimento dos sistemas contendo PHMB não foi afetado pela força iônica do meio de imersão, porém foi diminuído com o aumento da temperatura. Desta maneira, sistemas líquido-cristalinos de monoleína e água foram obtidos e o processo de intumescimento foi caracterizado. Os sistemas apresentaram potencial para serem propostos como sistemas de liberação para administração de PHMB e estudos de liberação de fármacos serão realizados futuramente.

Monoolein is a polar lipid that absorbs water and forms liquid crystalline systems that are used as drug delivery systems for different medications. The aim of the present study was to investigate lamellar phases formed by monoolein and water as potential vehicles for the administration of polyhexamethylene biguanide (PHMB). Lamellar phase systems formed by monoolein and water containing PHMB were characterized by polarizing microscopy. Swelling studies were performed gravimetrically under different conditions for the evaluation of the effects of pH, ionic strength and temperature. Analyses of swelling profiles, swelling kinetics and maximum swelling capacity were performed. The lamellar phase systems of monoolein and water obtained in the presence of PHMB absorbed water very quickly following second-order swelling kinetics and formed a cubic phase. The swelling of the systems was not influenced by the presence of the drug in the immersion media studied, except under acidic conditions, in which the drug exhibited increased water uptake. The swelling of systems containing PHMB was not affected by the ionic strength of the immersion media, but was reduced with an increase in temperature. Liquid crystalline systems of monoolein and water were obtained and swelling behavior was investigated. The systems exhibited the potential for use as a drug delivery system for PHMB administration. However, further drug-release studies should be performed.

O problema da dose em homeopatia: avaliação do efeito de altas diluições de arsenicum album 30ch em ratos intoxicados com arsênico / The problem of dose in homeopathy: evaluation of the effect of high dilutions of Arsenicum album 30cH on rats intoxicated with arsenic

Background: Although scientific studies have confirmed the action of homeopathic high dilutions in living organisms an endless debate on the choice of the most fitting dilution, the frequency of administration and the dose (amount of medicine) still remains. Aims: This study sought to assess the in vivo effect of 2 different concentrations of Arsenicum album 30cH in order to elucidate some problems in the homeopathic notion of dose. Methods: Male Wistar rats previously intoxicated with sodium arsenate by peritoneal injection were treated with undiluted Ars 30cH and Ars 30cH in 1% solution administered by oral route. Atomic absorption spectroscopy was employed to measure the levels of arsenic retained in the animals as well as the amounts eliminated through urine. Urine samples were collected before and after and during treatment. A positive control group (intoxicated animals) and negative control group (nonintoxicated animals) were administered only the vehicle used to prepare the medicine (ethanol). Results: The groups treated with undiluted Ars 30cH and Ars 30cH in 1% solution eliminated significant amounts of arsenic through urine when compared to the control groups. The group treated with undiluted Ars 30cH eliminated significantly higher amounts of arsenic than the group treated with the same medicine in 1% solution. Conclusion: These results suggest that undiluted Ars 30cH was more effective than in 1% solution in this experimental model.(AU)

Background: Although scientific studies have confirmed the action of homeopathic high dilutions in living organisms an endless debate on the choice of the most fitting dilution, the frequency of administration and the dose (amount of medicine) still remains. Aims: This study sought to assess the in vivo effect of 2 different concentrations of Arsenicum album 30cH in order to elucidate some problems in the homeopathic notion of dose. Methods: Male Wistar rats previously intoxicated with sodium arsenate by peritoneal injection were treated with undiluted Ars 30cH and Ars 30cH in 1% solution administered by oral route. Atomic absorption spectroscopy was employed to measure the levels of arsenic retained in the animals as well as the amounts eliminated through urine. Urine samples were collected before and after and during treatment. A positive control group (intoxicated animals) and negative control group (nonintoxicated animals) were administered only the vehicle used to prepare the medicine (ethanol). Results: The groups treated with undiluted Ars 30cH and Ars 30cH in 1% solution eliminated significant amounts of arsenic through urine when compared to the control groups. The group treated with undiluted Ars 30cH eliminated significantly higher amounts of arsenic than the group treated with the same medicine in 1% solution. Conclusion: These results suggest that undiluted Ars 30cH was more effective than in 1% solution in this experimental model.(AU)

Use of an ?electronic tongue? in the assessment of highly diluted systems / Use of an ?electronic tongue? in the assessment of highly diluted systems

Introduction: ?Eletronic tongue? is a device commonly used in the analysis of tastants, heavy metal ions, fruit juice, wines and also in the development of biosensors [1-3]. Briefly, the e-tongue is constituted by sensing units formed by ultrathin films of distinct materials deposited on gold interdigitated electrodes, which are immersed in liquid samples, followed by impedance spectroscopy measurements [1]. The e-tongue sensor is based on the global selectivity concept, i.e., the materials forming the sensing units are not selective to any substance in the samples, therefore, it allows the grouping of information into distinct patterns of response, enabling the distinction of complex liquid systems [1].Conclusion: Despite the differences of data obtained along distinct days of analysis, the e-tongue could detect differences among the samples tested, even considering the highly diluted cases studied.(AU)

Celecoxib determination in different layers of skin by a newly developed and validated HPLC-UV method.

A simple, rapid and sensitive analytical procedure for the measurement of celecoxib (CXB) levels in skin samples after in vitro penetration studies was developed and validated. In vitro permeability studies in porcine skin were performed for quantification of CXB at different layers of skin, the stratum corneum (SC) and epidermis plus dermis (EP + D) as well as in the acceptor solution (AS) to assess CXB permeation through skin. CXB was quantified by HPLC using a C18 column and UV detection at 251 nm. The mobile phase was methanol-water 72:28 (v/v) and the flow-rate was 0.8 mL/min. The CXB retention time was 5 min. The assay was linear for CBX in the concentration range of 0.1-3.0 µg/mL in the AS (drug permeated through skin) and 5.0-50.0 µg/mL for drug retained in SC and [EP + D] in vitro. The linear correlation coefficients for the different calibration curves were equal or greater than 0.99. Intra- and inter-assay variabilities were below 8.0%. Extraction of CXB from skin samples showed recoveries higher than 95.0% after 15 min of ultrasonic sound and centrifugation at 2500 rpm for 3 min. The method was considered appropriate for the assay of CXB in skin samples, after in vitro cutaneous penetration studies.

The problem of dose in homeopathy: evaluation of the effect of high dilutions of Arsenicum album 30cH on rats intoxicated with arsenic / O problema da dose em homeopatia: avaliação do efeito de altas diluições de Arsenicum album 30cH em ratos intoxicados com arsênico / El problema de la dosis en homeopatía: evaluación del efecto de altas diluciones de Arsenicum album 30cH en ratones intoxicados con arsénico

Background: Although scientific studies have confirmed the action of homeopathic high dilutions in living organisms an endless debate on the choice of the most fitting dilution, the frequency of administration and the dose (amount of medicine) still remains. Aims: This study sought to assess the in vivo effect of 2 different concentrations of Arsenicum album 30cH in order to elucidate some problems in the homeopathic notion of dose. Methods: Male Wistar rats previously intoxicated with sodium arsenate by peritoneal injection were treated with undiluted Ars 30cH and Ars 30cH in 1% solution administered by oral route. Atomic absorption spectroscopy was employed to measure the levels of arsenic retained in the animals as well as the amounts eliminated through urine. Urine samples were collected before and after and during treatment. A positive control group (intoxicated animals) and negative control group (non-intoxicated animals) were administered only the vehicle used to prepare the medicine (ethanol). Results: The groups treated with undiluted Ars 30cH and Ars 30cH in 1% solution eliminated significant amounts of arsenic through urine when compared to the control groups. The group treated with undiluted Ars 30cH eliminated significantly higher amounts of arsenic than the group treated with the same medicine in 1% solution. Conclusion: These results suggest that undiluted Ars 30cH was more effective than in 1% solution in this experimental model.

Introdução: embora estudos científicos têm confirmado a ação das altas diluições homeopáticas em organismos vivos, permanece o debate infindável acerca da escolha da diluição mais adequada, a frequência de administração e a dose (quantidade de medicamento). Objetivos: este estudo procurou avaliar o efeito in vitro de 2 concentrações diferentes de Arsenicum album 30cH a fim de elucidar alguns aspectos da noção homeopática de dose. Métodos: ratos Wistar machos previamente intoxicados com arseniato de sódio por injeção peritoneal foram tratados com Ars 30cH não diluído ou diluído 1% por via oral. Foi utilizada espectroscopia de absorção atômica para medir os níveis de arsênico retido no organismo e eliminado através da urina. As amostras de urina foram colhidas antes, após e durante o tratamento. Os grupos controle positivo (animais intoxicados) e negativo (animais não intoxicados) receberam apenas o veículo utilizado para preparar o medicamento (etanol). Resultados: os grupos tratados com Ars 30cH não diluído e diluído em solução 1% eliminaram quantidades significativamente maiores de arsênico através da urina por comparação aos grupos controle. O grupo tratado com Ars 30cH não diluído eliminou quantidades significativamente maiores de arsênico que o grupo tratado com o mesmo medicamento em solução 1%. Conclusão: esses resultados sugerem que Ars 30cH não diluído foi mais efetivo que a solução 1% do mesmo neste modelo experimental.

Introducción: aunque estudios científicos han confirmado la acción de las altas diluciones homeopáticas en organismos vivos, permanece sin resolver la discusión acerca de la elección de la dilución más adecuada, la frecuencia de administración y la dosis (cantidad de medicamento). Objetivos: este estudio buscó evaluar el efecto in vitro de 2 concentraciones diferentes de Arsenicum album 30cH para dirimir algunos problemas en la noción homeopática de dosis. Métodos: ratones Wistar macho previamente intoxicados con arseniato de sodio por inyección peritoneal fueron tratados con Ars 30cH sin diluir o diluido en solución 1% por vía oral. Fue utilizada espectroscopía de absorción atómica para medir los niveles de arsénico retenidos en el organismo y eliminados por orina. Las muestras de orina fueron recogidas antes, durante y después del tratamiento. Los grupos control positivo (animales intoxicados) y negativo (animales no intoxicados) recibieron exclusivamente el vehículo utilizado para preparar el medicamento (etanol). Resultados: los grupos tratados con Ars 30cH no diluido y diluido 1% eliminaron cantidades significativamente mayores de arsénico por orina que los controles. El grupo tratado con Ars 30cH no diluido eliminó cantidades significativamente mayores de arsénico por orina que el grupo tratado con el mismo medicamento diluido 1%. Conclusión: estos resultados sugieren que Ars 30cH no diluido fue más efectivo que cuando diluido 1% en este modelo experimental.

The problem of dose in homeopathy: evaluation of the effect of high dilutions of Arsenicum album 30cH on rats intoxicated with arsenic / O problema da dose em homeopatia: avaliação do efeito de altas diluições de Arsenicum album 30cH em ratos intoxicados com arsênico / El problema de la dosis en homeopatía: evaluación del efecto de altas diluciones de Arsenicum album 30cH en ratones intoxicados con arsénico

Background: Although scientific studies have confirmed the action of homeopathic high dilutions in living organisms an endless debate on the choice of the most fitting dilution, the frequency of administration and the dose (amount of medicine) still remains. Aims: This study sought to assess the in vivo effect of 2 different concentrations of Arsenicum album 30cH in order to elucidate some problems in the homeopathic notion of dose. Methods: Male Wistar rats previously intoxicated with sodium arsenate by peritoneal injection were treated with undiluted Ars 30cH and Ars 30cH in 1% solution administered by oral route. Atomic absorption spectroscopy was employed to measure the levels of arsenic retained in the animals as well as the amounts eliminated through urine. Urine samples were collected before and after and during treatment. A positive control group (intoxicated animals) and negative control group (non-intoxicated animals) were administered only the vehicle used to prepare the medicine (ethanol). Results: The groups treated with undiluted Ars 30cH and Ars 30cH in 1% solution eliminated significant amounts of arsenic through urine when compared to the control groups. The group treated with undiluted Ars 30cH eliminated significantly higher amounts of arsenic than the group treated with the same medicine in 1% solution. Conclusion: These results suggest that undiluted Ars 30cH was more effective than in 1% solution in this experimental model.(AU)

Introdução: embora estudos científicos têm confirmado a ação das altas diluições homeopáticas em organismos vivos, permanece o debate infindável acerca da escolha da diluição mais adequada, a frequência de administração e a dose (quantidade de medicamento). Objetivos: este estudo procurou avaliar o efeito in vitro de 2 concentrações diferentes de Arsenicum album 30cH a fim de elucidar alguns aspectos da noção homeopática de dose. Métodos: ratos Wistar machos previamente intoxicados com arseniato de sódio por injeção peritoneal foram tratados com Ars 30cH não diluído ou diluído 1% por via oral. Foi utilizada espectroscopia de absorção atômica para medir os níveis de arsênico retido no organismo e eliminado através da urina. As amostras de urina foram colhidas antes, após e durante o tratamento. Os grupos controle positivo (animais intoxicados) e negativo (animais não intoxicados) receberam apenas o veículo utilizado para preparar o medicamento (etanol). Resultados: os grupos tratados com Ars 30cH não diluído e diluído em solução 1% eliminaram quantidades significativamente maiores de arsênico através da urina por comparação aos grupos controle. O grupo tratado com Ars 30cH não diluído eliminou quantidades significativamente maiores de arsênico que o grupo tratado com o mesmo medicamento em solução 1%. Conclusão: esses resultados sugerem que Ars 30cH não diluído foi mais efetivo que a solução 1% do mesmo neste modelo experimental.(AU)

Introducción: aunque estudios científicos han confirmado la acción de las altas diluciones homeopáticas en organismos vivos, permanece sin resolver la discusión acerca de la elección de la dilución más adecuada, la frecuencia de administración y la dosis (cantidad de medicamento). Objetivos: este estudio buscó evaluar el efecto in vitro de 2 concentraciones diferentes de Arsenicum album 30cH para dirimir algunos problemas en la noción homeopática de dosis. Métodos: ratones Wistar macho previamente intoxicados con arseniato de sodio por inyección peritoneal fueron tratados con Ars 30cH sin diluir o diluido en solución 1% por vía oral. Fue utilizada espectroscopía de absorción atómica para medir los niveles de arsénico retenidos en el organismo y eliminados por orina. Las muestras de orina fueron recogidas antes, durante y después del tratamiento. Los grupos control positivo (animales intoxicados) y negativo (animales no intoxicados) recibieron exclusivamente el vehículo utilizado para preparar el medicamento (etanol). Resultados: los grupos tratados con Ars 30cH no diluido y diluido 1% eliminaron cantidades significativamente mayores de arsénico por orina que los controles. El grupo tratado con Ars 30cH no diluido eliminó cantidades significativamente mayores de arsénico por orina que el grupo tratado con el mismo medicamento diluido 1%. Conclusión: estos resultados sugieren que Ars 30cH no diluido fue más efectivo que cuando diluido 1% en este modelo experimental.(AU)

Evaluation of the effect of different concentrations of Arsenicum album 6cH on intoxicated rats / Avaliação do efeito de diferentes concentrações de Arsenicum album 6cH em ratos intoxicados

Aims: Homeopaths diverge on the concept of dose, i.e. the amount of drug that a patient must take to alter his or her state of disease. In order to stimulate reflections on this concept, this study sought to evaluate in vivo the effect of different concentrations of Arsenicum album 6cH prepared according to homeopathic pharmacotechnics. Methods: male Wistar rats were intoxicated with arsenic and then treated with Arsenicum album 6cH and Arsenicum album 6cH diluted at 1%, administered orally. The amount of arsenic retained in the animals’ organism and that eliminated by urine were measured through atomic absorption spectroscopy. Samples of urine were collected before and after intoxication and during treatment. The positive control group (intoxicated animals) and the negative control group (non-intoxicated animals) received only the vehicle used in the preparation of the medicine. Results: Groups treated with Arsenicum album 6cH and Arsenicum album 6cH diluted at 1% eliminated significant amounts of arsenic when compared to the control groups. The group treated with Arsenicum album 6cH eliminated significantly higher amounts of arsenic than the group treated with the diluted medicine at 1%. Conclusion: results suggest that Arsenicum album 6cH should not be diluted as not to compromise its effectiveness in the treatment of rats intoxicated with arsenic.

Objetivos: Há divergência entre os homeopatas a respeito do conceito de dose, entendida como a quantidade de medicamento que o paciente deve ingerir para modificar o estado de doença. Para estimular a reflexão sobre este tópico, o presente estudo procurou avaliar o efeito in vivo de diferentes concentrações de Arsenicum album 6cH preparado segundo a farmacotécnica homeopática. Métodos: ratos Wistar machos foram intoxicados com arsênico e após, medicados com Arsenicum album 6cH e o mesmo diluído a 1% por via oral. O arsênico retido no organismo dos animais assim como o eliminado através da urina foi quantificado através de espectroscopia de absorção atômica. Amostras de urina foram colhidas antes e após a intoxicação e durante o tratamento. O grupo controle positivo (animais intoxicados) e o grupo controle negativo (animais não intoxicados) receberam apenas o veículo utilizado no preparo do medicamento. Resultados: os grupos tratados com Arsenicum album 6cH e Arsenicum album 6cH 1% eliminaram quantidades significativas de arsênico por comparação com os grupos controle. O grupo tratado com Arsenicum album 6cH eliminou quantidades significativamente maiores de arsênico que o grupo tratado com o mesmo medicamento diluído a 1%. Conclusão: os resultados sugerem que Arsenicum album 6cH não deve ser diluído a fim de não comprometer sua efetividade no tratamento de ratos intoxicados com arsênico.

Evaluation of the effect of different concentrations of Arsenicum album 6cH on intoxicated rats / Avaliação do efeito de diferentes concentrações de Arsenicum album 6cH em ratos intoxicados

Aims: Homeopaths diverge on the concept of dose, i.e. the amount of drug that a patient must take to alter his or her state of disease. In order to stimulate reflections on this concept, this study sought to evaluate in vivo the effect of different concentrations of Arsenicum album 6cH prepared according to homeopathic pharmacotechnics. Methods: male Wistar rats were intoxicated with arsenic and then treated with Arsenicum album 6cH and Arsenicum album 6cH diluted at 1%, administered orally. The amount of arsenic retained in the animals’ organism and that eliminated by urine were measured through atomic absorption spectroscopy. Samples of urine were collected before and after intoxication and during treatment. The positive control group (intoxicated animals) and the negative control group (non-intoxicated animals) received only the vehicle used in the preparation of the medicine. Results: Groups treated with Arsenicum album 6cH and Arsenicum album 6cH diluted at 1% eliminated significant amounts of arsenic when compared to the control groups. The group treated with Arsenicum album 6cH eliminated significantly higher amounts of arsenic than the group treated with the diluted medicine at 1%. Conclusion: results suggest that Arsenicum album 6cH should not be diluted as not to compromise its effectiveness in the treatment of rats intoxicated with arsenic.(AU)

Objetivos: Há divergência entre os homeopatas a respeito do conceito de dose, entendida como a quantidade de medicamento que o paciente deve ingerir para modificar o estado de doença. Para estimular a reflexão sobre este tópico, o presente estudo procurou avaliar o efeito in vivo de diferentes concentrações de Arsenicum album 6cH preparado segundo a farmacotécnica homeopática. Métodos: ratos Wistar machos foram intoxicados com arsênico e após, medicados com Arsenicum album 6cH e o mesmo diluído a 1% por via oral. O arsênico retido no organismo dos animais assim como o eliminado através da urina foi quantificado através de espectroscopia de absorção atômica. Amostras de urina foram colhidas antes e após a intoxicação e durante o tratamento. O grupo controle positivo (animais intoxicados) e o grupo controle negativo (animais não intoxicados) receberam apenas o veículo utilizado no preparo do medicamento. Resultados: os grupos tratados com Arsenicum album 6cH e Arsenicum album 6cH 1% eliminaram quantidades significativas de arsênico por comparação com os grupos controle. O grupo tratado com Arsenicum album 6cH eliminou quantidades significativamente maiores de arsênico que o grupo tratado com o mesmo medicamento diluído a 1%. Conclusão: os resultados sugerem que Arsenicum album 6cH não deve ser diluído a fim de não comprometer sua efetividade no tratamento de ratos intoxicados com arsênico.(AU)

Preparation and scalin up of a low phenylalanine enzymatic hydrolysate of bovine whey proteins

We describe the preparation of pancreatic enzymes hydrolysate of milk whey proteins containing low levels of aromatic amino acids. Pancreatin and trypsin/chymotrypsin (6.3 percent w/w protein) when used to hydrolyze whey proteins for 27 h at 37±2 °C, released 74 percent of the Phe, 100 percent of the Tyr and 100 percent of the Trp as free amino acids. Most of the free aromatic amino acids present in 2 kg hydrolysate were separated from the remaining peptides and other amino acids by gel filtration on a 15 liter Sephadex G-25 column eluted with 5 percent acetic acid at 60 liters 'h POT. -1' 25°C. The product, recovered in 37 percent yield, contained 0.70 mmol Phe, 0.41 mmol Tyr, and <0.01mmol Trp/100mmol recovered amino acids. The hydrolysate had a general amino acid composition similar to the whey proteins from which it was prepared and could be use as a nitrogen source for patients with phenylketonuria or tyrosinemia after the addition of appropriate aromatic amino acids...