The underlying electrode causes the reported ‘electro-catalysis’ observed at C60-modified glassy carbon electrodes in the case of N-(4-hydroxyphenyl)ethanamide and salbutamol

The reported ‘electro-catalysis’ of C₆₀-film-modified electrodes for the electrochemical oxidation of N-(4-hydroxyphenyl)ethanamide and salbutamol has been explored at boron-doped diamond and glassy carbon electrodes. Using both C₆₀-film-modified boron-doped diamond and glassy carbon as underlying electrode substrates no electro-catalytic response is observed using the target analytes but rather the C₆₀ serves to block the electrode surface.A common experimental protocol used by researchers in this field is to electrochemically pre-treat the C₆₀-film-modified electrode. The response of employing this electrochemical pre-treatment at both bare glassy carbon and boron-doped diamond electrodes using the target analytes reveals that no effect on the electrochemical responses obtained at the boron-doped diamond electrode whereas a slight but significant effect occurs on glassy carbon which is attributed to the likely introduction of surface oxygenated species.Consequently the previously reported ‘electro-catalysis’ using C₆₀-film-modified electrode is not due to C₆₀ itself being catalytic, but rather that substrate activation through electrode pre-treatment is responsible for the observed ‘electro-catalysis’ likely through the introduction of surface oxygenated species.This work clearly shows that substrate activation is an important parameter which researchers studying C₆₀-film-modified electrodes, especially in electro-analysis needs to be considered.     

Quantifying the degree of disorder in micronized salbutamol sulfate using moisture sorption analysis

Salbutamol sulfate is often micronized for use in dry powder inhalers. Therefore, it is of high interest to quantify the amorphous amount. It was investigated whether moisture sorption is able to measure the amorphous content of salbutamol sulfate. Different mixtures of amorphous and crystalline salbutamol sulfate were analyzed by moisture sorption. The amorphous material was obtained by spray drying. The measurement results were used to plot a calibration curve, which was used to quantify the amorphous amount in micronized salbutamol sulfate.     

A novel apparatus for the determination of solubility in pressurized metered dose inhalers

The accurate solubility of salbutamol sulfate, budesonide, and formoterol fumarate dihydrate in hydrofluoroalkane propellant 134a at 25°C for 24 h, are reported. The authors describe a novel reusable in-line pressurized solubility apparatus containing an integral filter holder and a continuous decrimpable valve for the determination of drug/excipients solubility in pressurized metered dose inhalers. The solubility was determined by high-performance liquid chromatography. Solubility of salbutamol sulfate was determined as being below the detection limits while budesonide and formoterol fumarate dihydrate solubility were 23.136 ± 2.951 μg.g^-1 and 0.776 ± 1.023 μg.g^-1, respectively (n = 3). This novel solubility apparatus offers an improved ease of use and potential higher analytical throughput.     

Gas-phase synthesis of l-leucine-coated micrometer-sized salbutamol sulphate and sodium chloride particles

Coating of micrometer-sized particles of salbutamol sulphate or sodium chloride with the amino acid l-leucine in the gas phase is described. A novel method to synthesize core particles and coat them with l-leucine simultaneously was carried out in an aerosol flow reactor. The coating was prepared via temperature-induced heterogeneous nucleation of l-leucine vapor on the 0.6-1.0 µm core particles, and subsequent growth of l-leucine crystals by physical vapor deposition. The core salbutamol particles were amorphous, whereas the NaCl core particles were crystalline. The l-leucine sublimation that took place at 140-195 °C depended on the identity of the core material due to (i) molecular interaction and (ii) phase mixing. The former was dominant with salbutamol/l-leucine particles and the latter was dominant with NaCl/l-leucine particles. During the vapor deposition, l-leucine formed a discontinuous coating layer of leafy-looking crystallites, with sizes from a few nanometers to hundreds of nanometers, pointing out from the core particle surface. The l-leucine deposition properties depended on the core morphology: l-leucine crystallites were distributed more evenly on salbutamol core surfaces than on salt core surfaces, where the crystallites were localized mainly on edges. The stability of coated salbutamol particles was retained during storage under humid conditions.     

动物及动物源性食品中禁用药物残留检验监控研究

药物残留直接影响进出口动物源性食品的质量,更影响进出口贸易关系,并且还与消费者的安全卫生和身体健康密切相关。因此,掌握研究动物源性食品药物残留的现状,不仅对养殖企业具有重要意义,而且对检验检疫部门的检疫与监管具有现实意义。本文从动物源性食品现状调查了禁用物质氯霉素和β-受体激动剂的药物残留的研究及结果分析得知,动物源性食品药物残留企业自控及检验检疫部门监控基本到位,但广东地区个别企业还存在滥用氯霉素药物的现象,应引起高度重视。在调查的基础上,加强对各注册场药物使用的监督管理,使动物源性食品的药物残留监控水准在最短的时间内达到国际标准的要求。     

Electrochemical immunosensor based on polyaniline/poly (acrylic acid) and Au-hybrid graphene nanocomposite for sensitivity enhanced detection of salbutamol

An ultrasensitive electrochemical immunosensor based on nanogold particles (nano-Au), Prussian Blue (PB), polyaniline/poly (acrylic acid) (PANI (PAA)) and Au-hybrid graphene nanocomposite (AuGN) has been developed for the detection of salbutamol (SAL). Nano-Au, PB and PANI (PAA)-incorporated film was used to enhance the electroactivity, stability and catalytic activity for hydrogen reduction of the electrode. AuGN was used to immobilise chitosan, nano-Au and horseradish peroxidase-anti-SAL antibody (HRP-AAb). The resulting nanostructure (AuGN-HRP-AAb) was used as the label for the immunosensor. This is attributed to the high surface-to-volume ratio of graphene that allows the immobilisation of a high level of chitosan, nano-Au and HRP-AAb and its good electrical conductivity which can improve the electron transfer among HRP, H₂O₂ and electrode. Under the optimized conditions, a calibration plot for SAL was obtained with a linear range between 0.08 ng/mL and 1000 ng/mL (r = 0.9955). The detection limit was 0.04 ng/mL. The immunosensor was examined in real feed and pork samples for the analysis of SAL.     

液相色谱-串联质谱法测定猪肉及组织中沙丁胺醇的含量不确定度评定

目的分析液相色谱一串联质谱法检测猪肉及组织中沙丁胺醇的不确定度,探讨各因素对检验结果的影响。方法依据JJG1059.1-2012《测量不确定度评定与表示》和CNAS-GL06《化学分析中不确定度的评估指南》规定的方法和程序,分析影响测量不确定的来源,并对各不确定度分量进行了评估。结果合成各变量的不确定度,最终得到测定结果的扩展不确定度:(11.05±0.77)μg/kg(k=2)。结论影响检测结果不确定度的主要因素为回收率和标准曲线拟合,在实际测量过程严格控制实验条件可提高检测的准确性和可靠性。     

Development and Evaluation of Transdermal Salbutamol Delivering Systems

ABSTRACT

The transdermal drug delivery systems based on polymeric pseudolatex and matrix diffusion controlled systems for salbutamol were prepared and compared for in vitro skin permeation profile and in vivo performances. Poly (isobutylene) was used as release controlling polymer in both the systems. In vitro skin permeation was studied using the human cadavar skin in franz diffusion cell. Permeation rate constants for matrix diffusion controlled system and pseudolatices were 10.625 and 13.750 mcg/hr/cm² respectively. The prepared transdermal systems were tested on human volunteers having chronic reversible airways obstruction and compared with oral treatments (Asthaline). The in vivo drug plasma profiles following transdermal and oral treatments reveal that although peak plasma level by oral administration was higher in comparison with the transdermal treatments, troughs and peaks were discernible at dosing times. In the case of transdermal treatments, constant drug plasma and FEV₁ levels were recorded indicating controlled and systemic delivery of drug spaced over 30 hours. Among the prepared transdermal drug delivery systems, pseudolatices demonstrated better drug plasma profile, maintained at relatively higher level and flatter in appearance. The relative performance of the systems was noted to reflect in AUC and FEV₁.     

Antibiotic and synthetic growth promoters in animal diets: Review of impact and analytical methods

Food quality and safety have been a significant and pressing issue in recent years. In light of the FAO's definition of food security – the physical, social and economic access to sufficient and nutritious food – food safety plays a fundamental role. Animal feed and feeding is pivotal to the livestock industry, but the use of veterinary antibiotics (VAs) and synthetic growth promoters (SGP) diminishes the sustainability of the diets and can cause an accumulation of residues in animals (meat, milk and eggs) and the environment (water and soil pollution). Wastewater systems are another major pathway through which antibiotics and hormones can enter the environment, with negative consequences. In order to protect the planet through more sustainable feeding, the reduction of antibiotics and synthetic growth promoters is a key aim, in particular with the goal of reducing antibiotic resistance and allergies. Analytical methods play a crucial role in food analysis, to determine the presence of antibiotics and other additives. Recent methods are based on liquid chromatography with ultraviolet, fluorescence, or mass spectrophotometry detection, which is recognized as an essential technique in food analysis, able to identify more than 300 compounds in feed samples. In general, a monitoring program put in place to educate the population on the hazards of residues in animal products is necessary, in conjunction with a continuous decrease in the use of antibiotics and synthetic growth promoters in animal diets.     

Spray Drying of Aqueous Salbutamol Sulfate Solutions Using the Nano Spray Dryer B-90—The Impact of Process Parameters on Particle Size

In order to prepare spherical salbutamol sulfate particles of adjustable size, a Nano Spray Dryer B-90 was employed. A 3³ full-factorial design was used to investigate the influence of process parameters (mesh size, feed concentration, and drying air temperature) on particle size (median size and width of the particle size distribution), amount of product produced per time, and product yield. The median particle size was significantly influenced by all three factors of the statistical design. Within the design space studied, particle sizes of 1.0 to 6.4 µm were obtained. The width of the particle size distribution (span) increased with increasing mesh sizes. All particles with a particle size greater than 2.4 µm showed a bimodal particle size distribution. Generally, larger mesh sizes as well as higher concentrations led to an increase in the amount of product prepared per time. The corresponding values observed were from 0.4 to 75.8 mg/min. The product yield was independent of the process parameters studied. All products were amorphous after spray drying and were stable up to a relative humidity of 60% at a temperature of 25°C.