RESUMO
In order to improve biosurfactant production by Yarrowia lipolytica IMUFRJ 50682, a factorial design was carried out. A 2(4) full factorial design was used to investigate the effects of nitrogen sources (urea, ammonium sulfate, yeast extract, and peptone) on maximum variation of surface tension (Delta ST) and emulsification index (EI). The best results (67.7% of EI and 20.9 mN m(-1) of Delta ST) were obtained in a medium composed of 10 g 1(-1) of ammonium sulfate and 0.5 g 1(-1) of yeast extract. Then, the effects of carbon sources (glycerol, hexadecane, olive oil, and glucose) were evaluated. The most favorable medium for biosurfactant production was composed of both glucose (4% w/v) and glycerol (2% w/v), which provided an EI of 81.3% and a Delta ST of 19.5 mN m(-1). The experimental design optimization enhanced Delta EI by 110.7% and Delta ST by 108.1% in relation to the standard process.
Assuntos
Técnicas de Cultura de Células/métodos , Tensoativos/metabolismo , Yarrowia/metabolismo , Glucose/metabolismo , Glicerol/metabolismo , Cinética , Nitrogênio/metabolismo , Análise de Regressão , Projetos de Pesquisa , Tensão SuperficialRESUMO
The evaluation of faults in a multipurpose pharmaceutical pilot plant used for production of polymer particles was performed, integrating traditional Fault Tree Analyses (FTA) and Monte Carlo procedures and employing tools of the quality risk management methodology for production of medicines. The plant was divided into four basic processes: (i) receipt and sampling of materials; (ii) treatment of purified water; (iii) reaction; and (iv) lyophilization and purification. For each process, the most critical failure was selected, and the FTA was built. Selection of basic events considered the most important effects on the final quality of the medicine. Then, the FTA was reduced to basic events using Boolean algebra. The quantitative assessment was made by assigning failure rate values for each event. The reliability data of the failure rates were based on the literature that deals with similar processes. The frequencies for each fault were determined through Monte Carlo simulations, considering that fault probability distributions followed the exponential distribution. When failure rate (Ê) data are available, the quality management can establish a prediction of plant behavior over a period. This scenario is consistent and coherent with practices of pharmaceutical sites, since occurrence of high rates of failure must be corrected immediately in order to preserve the safety of the operation.
Assuntos
Indústria Farmacêutica/organização & administração , Método de Monte Carlo , Gestão de Riscos/organização & administração , Projetos Piloto , Controle de QualidadeRESUMO
Molecular dynamics simulations have been performed on the interface between linear saturated hydrocarbons and water in the presence of an asphaltene molecule by measuring the properties such as mean square displacement, radial distribution function, density profile using ave/spatial command, and interfacial tension (IFT) by OPLS and TIP3P FF (force fields). The box of simulation contained one particle of asphaltene, 100 linear saturated hydrocarbons molecules, and 300 water molecules in mixture with interfacial appropriate positioning. The main results show that a small amount of asphaltene in the interface does not significantly alter the data of IFT and that the aliphatic and aromatic groups have preferred orientation.
RESUMO
Abstract The present work reports the implementation of the Hazard Analysis Critical Control Point (HACCP) methodology to analyze the water purification system of a pharmaceutical site, in order to assure the system quality and prevent failures. As a matter of fact, the use of HACCP for development and implementation of Quality Risk Management (QRM) is not usual in pharmaceutical plants and it is applied here to improve the performance of the water purification system of a polymerization pilot plant used to manufacture pharmaceutical grade polymer microparticles. Critical Control Points (CCP) were determined with the aid of a decision tree and questions were made to characterize whether identified hazards constitute actual CCPs and should be monitored. When deviations were detected, corrective actions were performed and action plans were used for following-up and implementation of corrective actions. Finally, microbiological and physicochemical parameters were analyzed and the obtained results were regarded as appropriate. Therefore, it is shown that HACCP constitutes an effective tool for identification of hazards, establishment of corrective actions and monitoring of the critical control points that impact the process and the quality of the final pharmaceutical product most significantly.
Assuntos
Gestão de Riscos/classificação , Purificação da Água/instrumentação , Análise de Perigos e Pontos Críticos de Controle/métodos , Monitoramento Ambiental/instrumentação , Gestão da Qualidade Total/métodos , Indústria Farmacêutica/classificação , Metodologia como Assunto , Relatório de PesquisaRESUMO
This study aimed to synthesize and characterize nanoparticles (NPs) of poly(methyl methacrylate) (PMMA) and evaluate their ability to incorporate plant extracts with antitumor activity and low dissolution in aqueous media. The extract used was n-hexane partition of the methanol extract of Piper cabralanum (PCA-HEX). PMMA NPs were obtained using the mini-emulsion method, which was able to encapsulate almost 100% of PCA-HEX. The synthesized polymeric particles presented with a size of 200 nm and a negative charge. Cytotoxicity tests by MTT and trypan blue assays showed that NPs without PCA-HEX did not kill leukemic cells (K562 cells). NPs containing PCA-HEX were able to enhance cell death when compared to pure extract. The results showed that PMMA NPs could be useful as a drug delivery system as they can enhance the antitumor activity of the PCA-HEX extract by more than 20-fold. PMMA NPs containing plant extracts with antitumor activities may be an alternative to control the evolution of diseases such as leukemia.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Emulsões/química , Nanopartículas/química , Piper/química , Extratos Vegetais/farmacologia , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/química , Morte Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Emulsões/administração & dosagem , Hexanos/química , Humanos , Células K562 , Nanopartículas/administração & dosagem , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Polimetil Metacrilato/químicaRESUMO
Praziquantel (PZQ) is the drug recommended by the World Health Organization for treatment of schistosomiasis. However, the treatment of children with PZQ tablets is complicated due to difficulties to adapt the dose and the extremely bitter taste of PZQ. For this reason, poly (methyl methacrylate) nanoparticles loaded with Praziquantel (PZQ-NP) were developed for preparation of a new formulation to be used in the suspension form. For this reason, the main aim of the present study was to evaluate the pharmacokinetic (PK) profile of PZQ-NP, through HPLC-MS/MS assays. Analyses were performed with an Omnisphere C18 column (5.0 µm×4.6 mm×150.0 mm), using a mixture of an aqueous solution containing 0.1 wt% of formic acid and methanol (15:85-v/v) as the mobile phase at a flow rate of 0.800mL/min. Detection was performed with a hybrid linear ion-trap triple quadrupole mass spectrometer with multiple reactions monitoring in positive ion mode via electrospray ionization. The monitored transitions were m/z 313.18>203.10 for PZQ and m/z 285.31>193.00 for the Internal Standard. The method was validated with the quantification limit of 1.00 ng/mL, requiring samples of 25 µL for analyses. Analytic responses were calibrated with known concentration data, leading to correlation coefficients (r) higher than 0.99. Validation performed with rat plasma showed that PZQ was stable for at least 10 months when stored below -70 °C (long-term stability), for at least 17 h when stored at room temperature (RT, 22 °C) (short-term stability), for at least 47 h when stored at room temperature in auto-sampler vials (post-preparative stability) and for at least 8 successive freeze/thaw cycles at -70 °C. For PK assays, Wistar rats, weighing between 200 and 300 g were used. Blood samples were collected from 0 to 24 h after oral administration of single doses of 60 mg/kg of PZQ-NP or raw PZQ (for the control group). PZQ was extracted from plasma by liquid-liquid extraction with terc-butyl methyl ether. The values obtained for maximum concentration (C(max)) and area under curve (AUC) for the PZQ-NP group were about 3 times smaller than the respective values obtained for the control group. However, the time for achieving maximum concentration (T(max)), the elimination constant (Ke) and the half-life time of elimination (T(½ß)) were not statistically different. These results suggest that PZQ absorption is probably the rate-limiting step for obtainment of better PK parameters for PZQ-NP. Thus, further studies are needed to understand both the PZQ-NP absorption mechanisms and the drug diffusion process through the polymer matrix in vivo, in order to improve the PZQ-NP release profile.
Assuntos
Nanopartículas/metabolismo , Polimetil Metacrilato/farmacocinética , Praziquantel/farmacocinética , Espectrometria de Massas em Tandem/métodos , Animais , Cromatografia Líquida de Alta Pressão/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Nanopartículas/análise , Polimetil Metacrilato/análise , Praziquantel/análise , Ratos , Ratos WistarRESUMO
The aim of this work was the simultaneous encapsulation of magnetic nanoparticles (MNPs) and zinc(II) phthalocyanine (ZnPc) in poly(methyl methacrylate) (PMMA) (MNPsZnPc-PMMA) nanoparticles (NPs) by miniemulsion polymerization and to evaluate the photobiological activity and/or hyperthermia (HPT) against human glioblastoma cells (U87MG). MNPsZnPc-PMMA NPs presented an average diameter of 104 ± 2.5 nm with a polydispersity index (PdI) of 0.14 ± 0.03 and negative surface charge - 47 ± 2.2 mV (pH 7.4 ± 0.1). The encapsulation efficiency (EE%) of ZnPc was 85.7% ± 1.30. The release of ZnPc from PMMA NPs was slow and sustained without the presence of burst effect, indicating a homogeneous distribution of the drug in the polymeric matrix. In the biological assay, MNPsZnPc-PMMA NPs showed considerable cytotoxic effect on U87MG cells only after activation with visible light at 675 nm (photodynamic therapy, PDT) or after application of an alternating magnetic field. The simultaneous encapsulation of MNPs and ZnPc in a drug delivery system with sustained release can be a new alternative for cancer treatment leading to significant tumor regression after minimum doses of heat dissipation and light.
Assuntos
Indóis/química , Nanopartículas/química , Compostos Organometálicos/química , Polimetil Metacrilato/química , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Preparações de Ação Retardada , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Emulsões , Humanos , Isoindóis , Luz , Campos Magnéticos , Nanopartículas de Magnetita , Nanopartículas/efeitos da radiação , Polimerização , Compostos de ZincoRESUMO
Propylene polymerization using unsymmetrical, ansa-metallocene complexes Me(2)Y(Ind)CpMMe(2) (Y = Si, C, M = Zr, Y = C, M = Hf) and the co-initiators methyl aluminoxane (PMAO), B(C(6)F(5))(3), and [Ph(3)C][B(C(6)F(5))(4)] was studied at a variety of propylene concentrations. Modeling of the polymer microstructure reveals that the catalysts derived from Me(2)Si(Ind)CpZrMe(2) and each of these co-initiators function under conditions where chain inversion is much faster than propagation (Curtin-Hammett conditions). Surprisingly, the microstructure of the PP formed was essentially unaffected by the nature of the counterion, suggesting similar values for the fundamental parameters inherent to two-state catalysts. The tacticity of PP was sensitive to changes in [C(3)H(6)] in the case of catalysts derived from Me(2)C(Ind)CpHfMe(2) and PMAO, or [Ph(3)C][B(C(6)F(5))(4)], but the average tacticity of the polymer produced at a given [C(3)H(6)] decreased in the order [Ph(3)C][B(C(6)F(5))(4)] > PMAO. With B(C(6)F(5))(3), the polymer formed was more stereoregular, and its microstructure was invariant to changes in monomer concentration. The PP pentad distributions in this case could be modeled by assuming that all three catalyst/cocatalyst combinations function with different values for the relative rates of insertion to inversion (Delta) but otherwise feature essentially invariant, intrinsic stereoselectivity for monomer insertion (alpha, beta), while the relative reactivity/stability (g/K) of the isomeric ion-pairs present seems to be only modestly affected, if at all. Similar conclusions can also be made about the published propylene polymerization behavior of the C(s)-symmetric Me(2)C(Flu)CpZrMe(2) complex with different counterions. For every counterion investigated, the principle difference appears to be the operating regime (Delta) rather than intrinsic differences in insertion stereoselectivity (alpha). Surprisingly, the ordering of the various counterions with respect to Delta does not agree with commonly accepted ideas about their coordinating ability. In particular, catalysts when activated with B(C(6)F(5))(3) appear to function at low values of Delta as compared to those featuring B(C(6)F(5))(4) (less coordinating) and FAl[(o-C(6)F(5))C(6)F(4)](3) (more coordinating) or PMAO (more coordinating) counterions where the ordering in Delta is MeB(C(6)F(5))(3) < B(C(6)F(5))(4) < FAl[(o-C(6)F(5))C(6)F(4)](3) approximately PMAO. Possible reasons for this behavior are discussed.