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1.
Schistosomiasis is one of the major public health problems worldwide. Even though this is a common illness among preschool children in poor countries, treatment is carried out mainly through the administration of praziquantel tablets, which has some disadvantages, such as the strong bitter taste. As an alternative to overcome this problem, the development of new encapsulated praziquantel formulations is demanded. For this reason, suspension polymerizations are carried out for the in situ encapsulation of praziquantel into polymer microparticles, using methyl methacrylate (MMA) and cationic compounds (diethylaminoethyl methacrylate, DEAEMA, and dimethylaminoethyl methacrylate, DMAEMA) as comonomers. This technique allows for the preparation of polymer microparticles with high encapsulation efficiencies (>90%) with characteristic sizes ranging from 0.5 to 1500 µm. Drug release profiles show that praziquantel is released from poly(methyl methacrylate) microparticles slowly due to the existence of strong diffusional resistance. On the other hand, the addition of cationic comonomers renders polymer particles sensitive to pH variations, allowing for faster release of praziquantel in acidic environments, as found in the stomach.  相似文献   
2.
After malaria, schistosomiasis (or bilharzia) is the second most prevalent disease in Africa, and is occurring in over 70 countries in tropical and subtropical regions. It is estimated that 600 million people are at risk of infection, 200 million people are infected, and at least 200 000 deaths per year are associated with the disease. All schistosome species are transmitted through contact with fresh water that is infested with free‐swimming forms of the parasite, which is known as cercariae and produced by snails. When located in the blood vessels of the host, larval and adult schistosomes digest red cells to acquire amino acids for growth and development. Vaccine candidates have been unsuccessful up to now. Against such devastating parasitic disease, the antischistosomal arsenal is currently limited to a single drug, praziquantel, which has been used for more than 35 years. Because the question of the reduction of the activity of praziquantel was raised recently, it is thus urgent to create new and safe antischistosomal drugs that should be combined with praziquantel to develop efficient bitherapies.  相似文献   
3.
 A procedure for the colorimetric assay of praziquantel has been developed. The method is based on the formation of charge-transfer complexes with p-chloranil (I), dichloronitrophenol (II), 2,3-dichloro-5,6 dicyano-p-benzoquinone (III), 7,7,8,8-tetracyanoquinodimethane (IV) and tetracyanoethylene (V) as π-acceptors to give highly coloured species. The coloured products are measured spectrophotometrically at 550, 425, 460, 844 and 393 nm for I, II, III, IV and V, respectively. Optimization of the different reaction conditions is described. The colour system obeyed Beer’s law in non-aqueous media in the concentration range 2.0–48 μg ml−1. It was stable for at least 4.0 h. The detection limit was found to be 0.6 μg ml−1. Applications of the procedure to the analysis of various pharmaceutical samples gave reproducible and accurate results. Further, the validity of the procedure was confirmed by applying the standard addition technique. The total average recovery was 100.2%. Received June 10, 2000. Revision December 23, 2000.  相似文献   
4.
本文报道了用吸附溶出伏安法测定毗喳酮.以悬汞电极为工作电极,在Na}B,O,-NaOH介质(pH=10)中,毗喳酮产生一尖锐的吸附还原峰,E,二一1. 29V (vs. SCE ),峰电流与毗喳酮浓度在2. 0 X 10-'-8. 0 X 10-smol " L-’范围内呈良好的线性关系.检测限为2. 0 X 10-0mol " L-'(富集90s).本文对毗喳酮在悬汞电极上的电化学行为进行了探讨,对测定毗喳酮的最佳条件进行了详细的选择,利用本法测定了片剂中毗喳酮含量,结果满意.  相似文献   
5.
6.
Transfer of six thin-layer chromatography (TLC) Global Pharma Health Fund E.V. Minilab manual protocols for detecting fake drugs in pharmaceutical products to quantitative high-performance TLC (HPTLC)-densitometry methods was performed following a previously published model process. The developed and validated methods for tablets or capsules containing atenolol, chloramphenicol, furosemide, glibenclamide, penicillin V potassium, and praziquantel involved use of a limited list of inexpensive, relatively nontoxic, readily available solvents and other reagents; silica gel 60?F254 plates; automated bandwise sample and standard solution application; ascending mobile phase development of plates in a chamber; and automated slit scanning densitometry for detection, identification, and quantification. Validation data for methods developed in an early version of the transfer model process that did not include standard addition validation are reported for pharmaceutical products containing amitriptyline HCl, amodiaquine, diphenhydramine HCl, and mebendazole.  相似文献   
7.
Praziquantel (PZQ) is the first line drug for the treatment of human Schistosoma spp. worm infections. However, it suffers from low activity towards immature stages of the worm, and its prolonged use induces resistance/tolerance. During the last 40 years, 263 PZQ analogues have been synthesized and tested against Schistosoma spp. worms, but less than 10% of them showed significant activity. Here, we propose a rationalization of the chemical space of the PZQ derivatives by a ligand-based approach. First, we constructed an in-house database with all PZQ derivatives available in the literature. This analysis shows a high heterogeneity in the data. Fortunately, all studies include PZQ as a reference, permitting the classification of compounds into three classes according to their activities. Models involving ligand-based pharmacophore and logistic regression were performed. Five physicochemical parameters were identified as the best to explain the biological activity. In the end, we proposed new PZQ derivatives with modifications at positions 1 and 7, we analysed them with our models, and we observed that they can be more active than the previously synthesized derivatives. The main goal of this work was to conduct the most valuable meta-pharmacometrics/pharmacoinformatics analysis with all Praziquantel medicinal chemistry data available in the literature.  相似文献   
8.
基于吡喹酮对Luminol-NaIO_4化学发光体系有较强的抑制作用,并结合流动注射分析技术,建立了测定吡喹酮的流动注射-化学发光(FI-CL)新方法。在最佳实验条件下,吡喹酮在4.0×10~(-8)~1.0×10~(-6) mol/L浓度范围内与相对化学发光强度呈良好的线性关系,该方法对测定吡喹酮显示出较高的灵敏度,检出限(LOD,3σ)为9.9×10~(-9) mol/L。对2.0×10~(-7) mol/L的吡喹酮平行测定11次,其相对标准偏差(RSD)为1.4%。采用该方法对猪饲料样品进行加标实验,回收率为98.5%~100%。该方法已经成功用于猪饲料样品中吡喹酮的测定。  相似文献   
9.
Schistosomiasis is a parasitic disease that affects millions of people, especially low‐income people, and is considered a major public health problem in underdeveloped countries. The drug used most often for the treatment of the disease is praziquantel (PZQ), which has a strong and characteristic bitter taste that makes treatment of children inconvenient. For this reason, the present work investigates the development of smart pH‐sensitive polymer microparticles produced through suspension polymerizations to be used as vehicles for the controlled release of praziquantel in the body. The microparticles are produced through copolymerization of methyl methacrylate and the cationic comonomers diethylaminoethyl methacrylate or dimethylaminoethyl methacrylate. The obtained results indicate that microparticles with sizes in the range of 10–1100 µm can be formed successfully, allowing high PZQ encapsulation efficiencies (>80%). Zeta potential analyses and drug release assays confirm the pH‐sensitive responses of the cationic copolymers, leading to effective release of PZQ (around 80% in pH 1.2) in acidic media that simulate the organic fluids present in the stomach.  相似文献   
10.
Carbamazepine is an antiepileptic drug widely used for the treatment of epilepsy. In the National Institute of Neurology, monitoring has been performed using the technique chemiluminescent microparticle immunoassay (CMIA) in an automated way during the last five years. The aim of this study was to develop a simple and rapid HPLC analytical method coupled to DAD‐UV detection for the determination of plasma concentrations of carbamazepine and compare its feasibility with those used in routine analysis. The developed HPLC method was fully validated and the applicability of the proposed method was verified through the analysis of plasma samples of patients and later compared with the quantification of the same plasma samples with the CMIA method. The limit of quantification obtained was 0.5 μg/mL. The mean value for recovery was 99.05% and the coefficient of variation (CV) was 5.6%. The precision and accuracy of this method were within the acceptable limits; inter‐ and intraday CV values were <10%. The correlation between the CMIA method and the developed HPLC method was very good (r ≈ 0.999). A Bland–Altman plot showed no significant bias between the results. The HPLC‐DAD method may be an alternative to determine and monitoring the carbamazepine levels in human plasma or serum. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
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