39 research outputs found

    Liposomes: methods and protocols

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    Validation of method to evaluate sanitary quality of lipophilic base cosmetics

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    A validação de método para a avaliação da qualidade sanitária de produto cosmético de base lipófila foi efetuada empregando-se neutralizantes químicos e diluição para a eliminação de efeito inibitório no crescimento microbiano. Para a preparação da amostra foi empregado miristato de isopropila e polissorbato 20. Além dessas substâncias, foi adicionado ao diluente 0,5% (p/v) de lecitina de soja visando à neutralização do cloreto de benzalcônio. Os ensaios foram efetuados objetivando a comprovação da ausência de efeito inibitório no crescimento microbiano decorrente de atividade antimicrobiana do produto, assim como dos agentes neutralizantes, tensoativos e solubilizante empregados no ensaio. Na avaliação quantitativa, os resultados demonstraram ausência de efeito inibitório no crescimento microbiano nas diluições 1:10 e 1:100. A porcentagem de microrganismos recuperados foi de, no mínimo, 93,2% indicando a validade do método de acordo com o critério oficial adotado. Com referência ao ensaio qualitativo, foi observado efeito inibitório na diluição 1:20 para os seguintes microrganismos: Pseudomonas aeruginosaeStaphylococcus aureus.Esse efeito foi eliminado empregando-se diluição 1:200, sendo, desta forma, essa diluição considerada válida para o ensaio.The validation of method to evaluate the sanitary quality of lipophilic base cosmetics was performed using chemical neutralizers and dilution in order to eliminate the inhibitory effect on the microbial growth. The preparation of the sample was performed aiming the homogeneity in the culture media. Isopropyl miristate was used for the solubilization of the sample and polysorbate 20 was used as surfactant. Besides these substances, it was added to the diluent 0.5% (w/v) of soy lecithin to neutralize the antimicrobial activity of the benzalkonium chloride. The purpose of the assays was to demonstrate the lack of inhibitory effect on the microbial growth due to antimicrobial activity of the product as well as of the neutralizing and solubilizing agents and the surfactant used in the assay. With regard to a quantitative evaluation, the results showed a lack of inhibitory effect of the product on the microbial growth in dilutions 1:10 and 1:100. The percentage of microbial recovery was at least 93.2% indicating the validation of the method in accordance with the official criteria adopted. As for the qualitative analysis, in dilution 1:20, it was noticed an inhibitory effect for the following microorganisms: Pseudomonas aeruginosa and Staphylococcus aureus.Since this mentioned effect was not noticed when dilution was 1:200, the latter dilution was considered valid for the assay

    Statistical evaluation of tablet coating processes: influence of pan design and solvent type

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    Partially and fully perforated pan coaters are among the most relevant types of equipment currently used in the process of coating tablets. The goal of this study was to assess the performance differences among these types of equipment employing a factorial design. This statistical approach allowed the simultaneous study of the process variables and verification of interactions among them. The study included partially-perforated and fully-perforated pan coaters, aqueous and organic solvents, as well as hypromellose-based immediate-release coating. The dependent variables were process time, energy consumption, mean weight of tablets and process yield. For the tests, placebo tablets with a mean weight of 250 mg were produced, divided into eight lots of two kilograms each and coated in duplicate, using both partially perforated pan and fully perforated pan coaters. The results showed a significant difference between the type of equipment used (partially and fully perforated pan coaters) with regard to process time and energy consumption, whereas no significant difference was identified for mean weight of the coated tablets and process yield.Entre os tipos de equipamentos de maior relevância utilizados atualmente no processo de revestimento de comprimidos estão os de tambor parcial e totalmente perfurados. A proposta desse trabalho foi avaliar as diferenças de desempenho entre esses equipamentos empregando projeto fatorial. Essa abordagem estatística possibilitou o estudo simultâneo das variáveis do processo, permitindo verificar interações entre elas. O trabalho incluiu equipamento com tambor parcialmente perfurado e totalmente perfurado, solventes aquoso e orgânico, assim como revestimento de liberação imediata à base de hipromelose. As variáveis dependentes ou respostas foram tempo de processo, consumo de energia, peso médio e rendimento do processo. Para os ensaios, foram produzidos comprimidos de placebo de 250 mg de peso médio, divididos em 8 lotes de dois quilogramas cada e revestidos em duplicata, tanto no equipamento com tambor parcialmente perfurado quanto no equipamento de tambor totalmente perfurado, obedecendo a matriz de ensaio previamente definida. Os resultados mostraram que existe diferença significativa entre equipamento de tambor parcialmente perfurado e totalmente perfurado, para tempo de processo e consumo de energia. Já para peso médio dos comprimidos revestidos e rendimento do processo, os dois equipamentos não apresentaram diferença significativa

    Statistical evaluation of tablet coating processes: influence of pan design and solvent type

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    Partially and fully perforated pan coaters are among the most relevant types of equipment currently used in the process of coating tablets. The goal of this study was to assess the performance differences among these types of equipment employing a factorial design. This statistical approach allowed the simultaneous study of the process variables and verification of interactions among them. The study included partially-perforated and fully-perforated pan coaters, aqueous and organic solvents, as well as hypromellose-based immediate-release coating. The dependent variables were process time, energy consumption, mean weight of tablets and process yield. For the tests, placebo tablets with a mean weight of 250 mg were produced, divided into eight lots of two kilograms each and coated in duplicate, using both partially perforated pan and fully perforated pan coaters. The results showed a significant difference between the type of equipment used (partially and fully perforated pan coaters) with regard to process time and energy consumption, whereas no significant difference was identified for mean weight of the coated tablets and process yield.Entre os tipos de equipamentos de maior relevância utilizados atualmente no processo de revestimento de comprimidos estão os de tambor parcial e totalmente perfurados. A proposta desse trabalho foi avaliar as diferenças de desempenho entre esses equipamentos empregando projeto fatorial. Essa abordagem estatística possibilitou o estudo simultâneo das variáveis do processo, permitindo verificar interações entre elas. O trabalho incluiu equipamento com tambor parcialmente perfurado e totalmente perfurado, solventes aquoso e orgânico, assim como revestimento de liberação imediata à base de hipromelose. As variáveis dependentes ou respostas foram tempo de processo, consumo de energia, peso médio e rendimento do processo. Para os ensaios, foram produzidos comprimidos de placebo de 250 mg de peso médio, divididos em 8 lotes de dois quilogramas cada e revestidos em duplicata, tanto no equipamento com tambor parcialmente perfurado quanto no equipamento de tambor totalmente perfurado, obedecendo a matriz de ensaio previamente definida. Os resultados mostraram que existe diferença significativa entre equipamento de tambor parcialmente perfurado e totalmente perfurado, para tempo de processo e consumo de energia. Já para peso médio dos comprimidos revestidos e rendimento do processo, os dois equipamentos não apresentaram diferença significativa

    Atividade antimicrobiana de quatro formulações diferentes de géis dentais em bactérias cariogênicas avaliada pelo método de regressão linear

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    The antimicrobial activity of four different dental gel formulas was evaluated on three microorganisms associated with cariogenesis: Streptococcus mutans, Lactobacillus casei and Actinomyces viscosus. The preliminary antimicrobial activity evaluation was performed using an agar diffusion method. In addition, the formulas were challenged using each microorganism with subsequent determinations of survivors at time intervals of 1, 5, 10, 20 and 30 minutes. The decimal reduction time (D-value) calculated from the obtained curves (logCFU/mL vs. time) was employed for the antimicrobial activity comparison of the formulas. The selected method for survivor enumeration was validated according to official compendia. Results revealed intense bactericidal activity, even at 1:2 dilution, on S. mutans and L. casei. The data concerning A. viscosus showed the absence of microbial reduction in the challenge employing diluted formulas at the selected time interval. The obtained D-values were 0.21, 2.08, 1.93 and 5.79 minutes for formulas 1, 2, 3 and 4, respectively. After comparing the obtained results, formula 1 can be considered to have the highest bactericidal activity.A atividade antimicrobiana de quatro diferentes fórmulas de gel dental foi avaliada empregando três microrganismos associados à cariogênese: Streptococcus mutans, Lactobacillus casei e Actinomyces viscosus. A avaliação preliminar foi efetuada utilizando método por difusão em ágar. Além disso, as fórmulas foram desafiadas empregando cada microrganismo e as determinações relativas aos sobreviventes foram efetuadas após 1, 5, 10, 20 e 30 minutos do desafio. O tempo de redução decimal (valor-D) foi calculado por meio das curvas obtidas (UFC/mL x tempo), objetivando a comparação da atividade antimicrobiana entre as fórmulas. O método selecionado para a enumeração dos sobreviventes foi validado de acordo com compêndio oficial. Os resultados revelaram intensa atividade antimicrobiana, inclusive na avaliação empregando diluição 1:2 dos produtos para os microrganismos Streptococcus mutans e Lactobacillus casei. Os dados relativos ao Actinomyces viscosus indicaram ausência de redução da população microbiana no desafio empregando produto diluído (1:2). Os valores-D obtidos foram 0,21, 2,08, 1,93 e 5,79 minutos para as fórmulas 1, 2, 3 e 4 respectivamente. Após comparação dos resultados obtidos, a fórmula 1 pode ser considerada aquela que apresentou maior atividade antimicrobiana

    Critical evaluation of the off-label indication and of the risks associated to the use of multi-dose vials on the treatment of age-related macular degeneration

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    Age-related macular degeneration (AMD) is an ocular inflammatory diseases treated mainly by means of a bevacizumab (Avastin®) or ranibizumab (Lucentis®) intravitreal injection. Among these drugs, only ranibizumab has a specific therapeutic indication for AMD. Considering that, the off-label use on ophthalmic therapy seems to become a rule when it should be an exception. Furthermore, bevacizumab presentation consists of multi-dose vials although it does not contain preservatives in its formula. The current literature review aimed at assessing the risks for the patient related to the use of off-label indication and multi-dose vials on AMD treatment. Considering this, the proposal related to the Brazilian Public Consultation no.10, dated September 12, 2012, which proposes the Clinical Protocol and Therapeutic Guidelines for AMD treatment, was evaluated. This systematic review allowed to conclude that the bevacizumab off-label indication results in increased risks for the patient when compared to the product with specific therapeutic indication for AMD treatment (ranibizumab), especially referring to the significant raise in the adverse events. The risks for the patient related to the multi-dose vial use, referring to the microbiological stability and dose precision, were also made clear.A degeneração macular relacionada à idade (DMRI) é uma doença ocular inflamatória tratada principalmente por injeção intravítrea de bevacizumabe (Avastin®) ou de ranibizumabe (Lucentis®). Entre os medicamentos citados, apenas o ranibizumabe tem indicação terapêutica específica para uso oftálmico. Considerando essa realidade, o uso off-label na terapia oftálmica parece constituir regra quando deveria ser exceção. Ademais, a apresentação do bevacizumabe consiste em frascos de múltipla-dose, embora esse medicamento não contenha conservante em sua fórmula. A presente revisão da literatura avaliou os riscos ao paciente relativos ao uso indicado off-label e de frascos de múltipla-dose no tratamento de DMRI. Nesse sentido, avaliou-se a proposta relativa à Consulta Pública Brasileira nº 10, de 12 de setembro de 2012, que propõe o Protocolo Clínico e Diretrizes Terapêuticas para o tratamento de DMRI. O levantamento sistemático de trabalhos científicos e de informações relevantes de banco de dados eletrônicos permitiu concluir que a indicação off-label do bevacizumabe acarreta riscos maiores ao paciente, quando comparado ao produto com indicação terapêutica específica para o tratamento de DMRI (ranibizumabe), especialmente quanto ao aumento significativo de eventos adversos. Evidenciaram-se, também, os riscos ao paciente relativos ao uso de frascos de múltipla-dose, quanto à estabilidade microbiológica e à precisão da dose

    Derivative spectrophotometric method for determination of acyclovir in polymeric nanoparticles

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    A derivative spectrophotometric method was validated for quantification of acyclovir in poly (n-butylcyanoacrylate) (PBCA) nanoparticles. Specificity, linearity, precision, accuracy, recovery, detection (LOD) and quantification (LOQ) limits were established for method validation. First-derivative at 295.2 nm eliminated interferences from nanoparticle ingredients and presented linearity for acyclovir concentrations ranging from 1.25 to 40.0 µg/mL (r = 0.9999). Precision and accuracy data demonstrated good reproducibility. Recovery ranged from 99.3 to 101.2. LOD was 0.08 µg/mL and LOQ, 0.25 µg/mL. Thus, the proposed method proved to be easy, low cost, and accurate, and therefore, an useful alternative to quantify acyclovir in nanoparticles

    Statistical process control of manufacturing tablets for antiretroviral therapy

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    In this study, the manufacturing process of lamivudine (3TC) and zidovudine (AZT) tablets (150+300 mg respectively) was evaluated using statistical process control (SPC) tools. These medicines are manufactured by the Fundação para o Remédio Popular “Chopin Tavares de Lima” (FURP) laboratory, and are distributed free of charge to patients infected with HIV by the Ministry of Health DST/AIDS national program. Data of 529 batches manufactured from 2012 to 2015 were collected. The critical quality attributes of weight variation, uniformity of dosage units, and dissolution were evaluated. Process stability was assessed using control charts, and the capability indices Cp, Cpk, Pp, and Ppk (process capability; process capability adjusted for non-centered distribution; potential or global capability of the process; and potential process capability adjusted for non-centered distribution, respectively) were evaluated. 3TC dissolution data from 2013 revealed a non-centered process and lack of consistency compared to the other years, showing Cpk and Ppk lower than 1.0 and the chance of failure of 2,483 in 1,000,000 tablets. Dissolution data from 2015 showed process improvement, revealed by Cpk and Ppk equal to 2.19 and 1.99, respectively. Overall, the control charts and capability indices showed the variability of the process and special causes. Additionally, it was possible to point out the opportunities for process changes, which are fundamental for understanding and supporting a continuous improvement environment
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