测定盐酸西布曲明的电位传感器的研制与应用

以四苯硼酸钠与盐酸西布曲明生成的离子缔合物为电活性物质,研制了盐酸西布曲明传感器。试验表明:盐酸西布曲明聚氯乙烯(PVC)膜传感器对盐酸西布曲明具有良好的选择性和电位响应特性。在pH 5的溶液中,电极电位呈现近能斯特响应,线性范围为1.0×10-6～1.0×10-1mol.L-1,斜率为50 mV.pc-1(26℃),检出限(3S/N)为5.62×10-7mol.L-1。将电极用于药物中盐酸西布曲明含量的测定,测得回收率为97.3%～100.2%,测定值的相对标准偏差(n=5)均小于2%。     

苯海拉明的拉曼光谱和红外光谱研究

测量并分析了盐酸苯海拉明的红外光谱和拉曼光谱。在Raman光谱中, 1001 cm-1出现一个极强峰, 在1030 cm-1和618 cm-1各有一个中等峰,此外,在红外光谱中, 714 cm-1和757 cm-1附近出现极强的吸收峰,认定这个化合物中存在单取代苯。C-N的对称伸缩振动出现在837 cm-1, 1433 cm-1和1470 cm-1分别为CH2和CH3的变形振动, 在红外光谱中, 1020 cm-1处明显的吸收峰属于C-O-C反对称伸缩振动。此外, 测量得到含量为25 mg苯海拉明药片的拉曼光谱与纯苯海拉明的拉曼峰比较一致, 可作为无损快速检测该药物的手段。     

Spectrophotofluorimetric Study of the Interaction between Trazodone Hydrochloride and Bovine Serum Albumin

Abstract

The binding of trazodone hydrochloride (TZH), an antidepressant drug, to bovine serum albumin (BSA) has been investigated by fluorescence spectroscopic analysis. The fluorescence emission of BSA (λ_em=350 nm) was quenched by TZH while that of this ligand was enhanced (λ_em=443 nm). The spectral behavior was consistent with the static quenching mechanism, and the apparent binding constant, K _a (1.05×10⁴ l mol^?1) as well as binding site number, n (～1), were estimated. Thermodynamic parameters obtained from the measured data at different temperatures showed that the binding of TZH to BSA involved predominantly hydrophobic interactions as well as smaller contributions from electrostatic forces. Phenylbutazone and ibuprofen were utilized as competitive markers for sites I and II, respectively, in the interaction of TZH with BSA. This competitive displacement procedure indicated that the likely binding was site I, i.e., subdomain IIA, and this was supported by the observation that up to 50% of this site marker, phenylbutazone, could be exchanged with TZH whilst only a few percent of ibuprofen were so affected.     

Flow Injection Chemiluminescence Determination of Difenidol Hydrochloride Using N-Chlorosuccinimide-Dichlorofluorescein Reaction

Abstract

A flow injection method combined with chemiluminescence detection was described for the determination of difenidol hydrochloride. Strong chemiluminescence was recorded when difenidol hydrochloride was added into the reaction mixture of N-chlorosuccinimide with dichlorofluorescein in alkaline medium. The experimental conditions that affected the chemiluminescence signal, including the concentrations of reactants, the reaction medium, and the instrumental parameters, were carefully optimized. Under the optimum experimental conditions, the enhanced chemiluminescence intensity was linear related to the concentration of difenidol hydrochloride in the range of 4.0 × 10^?9 to 4.0 × 10^?7 g/ml. The detection limit for difenidol hydrochloride was 7 × 10^?10 g/ml, and the sample throughput was 90/h. The relative standard deviation was 2.5% for 5.0 × 10^?8 g/ml difenidol hydrochloride solution (n = 11). The interference of common inorganic ions, excipients, and additives used in pharmaceutical preparation was studied, which showed the method has higher tolerance limit for these substances and has good selectivity. As a preliminary application, the method was applied to the determination of difenidol hydrochloride in tablets, and the satisfactory results were achieved.     

Spectrophotometric Assay of Fluphenazine HCL-Nortriptyline HCL Mixture in Tablets Using Fourier Function Method

Abstract

The Fourier function method has been applied to the independent determination of fluphenazine hydrochloride (FH) and nortriptyline hydrochloride (KH) (1:20) in both laboratory made mixtures and commercial tablets. The method is based on the absorbance measurement of FE (the minor component) in concentrated mixture solutions, which is then properly diluted prior to NH absorbance measure-     

Extractive Spectrophotometric Determination of Chlorprothixene Hydrochloride

ABSTRACT

A simple, rapid and accurate method for determination of chlorprothixene hydrochloride is presented. It is based on the liability of the chlorprothixene tertiary amine group nitrogen atom to form ion pair complexes with niobium (V) thiocyanate complex. The formed compound is insoluble in water but well soluble in some organic solvents. The reaction is followed spectrophotometrically by measuring the absorbance at λ= 362 nm. This property has been successfully used for the extractive spectrophotometric determination of chlorprothixene. Beer's law was obeyed in the range 9- 50 μg/ml of chlorprothixene hydrochloride. The method is suitable to the determination of analyte in commercial products. The results were compared with those obtained by the official procedure.     

七、八元瓜环对盐酸雷尼替丁的包合作用及缓释性能

研究了七元瓜环(Q[7])和八元瓜环(Q[8])与盐酸雷尼替丁(RH)的包合作用及包合物的体外药物缓释性能.采用紫外-可见光谱法测定了体系的包合比、包合稳定常数和药物累积释放度;用1H NMR技术考察了体系主-客体的包合作用.结果表明,Q[7]和Q[8]与RH在酸性及中性条件下均能发生1∶1包合作用,包合稳定常数分别为1.21×104和2.06×104 L/mol;在碱性条件下则不发生包合作用.原药RH,Q[7]-RH及Q[8]-RH包合物在人工胃液(pH=1.2)中的60 min累积释放度分别为89.1%,56.6%和38.4%;而在人工肠液(pH=6.8)中三者的60 min累积释放度分别为90.2%,58.7%和38.0%.实验结果表明,Q[7]及Q[8]包合对RH有明显的体外缓释作用.     

Colorimetric and Bromometric Determination of Pirbuterol Hydrochloride

Abstract

Two proposed methods are reported for the quantitation of pirbuterol hydrochloride, namely, (i) colorimetric and (ii) titrimetric methods. The colorimetric method is based on coupling betweem diazotized sulphanilamide and pirbuterol hydrochloride. Under the optimum conditions studied, the coupling product exhibits a maximum at 440 nm. Linear relation between absorbance, A, and concentration of pirbuterol hydrochloride is in the range 5–40 μgml^?1. The mean percentage obtained for capsules (Exirel^R ?15 mg) was 100.8 ± 0.7 whereas mean percentage recovery obtained for the authentic drug was 100.5 ± 0.8.

The titrimetric procedure involves bromination of authentic pirbuterol in acid medium and residual titration of excess bromine. The stoichiometry of the reaction was investigated and infra-red analysis, of the bromoderivative was carried out. When applied to capsules the bromometric method gave mean percentage of 100.18 ± 2.25.     

Colorimetric and Polarographic Methods of Analysis for Prenalterol Hydrochloride

Abstract

Two proposed methods have been described for the determination of prenalterol hydrochloride in acetate buffer (pH=4.1) as authentic material and in tablets form using a (i) colorimetric method based on reduction of ferric iron by prenalterol hydrochloride and subsequent measurement at 511 nm of the red color obtained by the treatment of the resultant ferrous iron with 1, 10-orthophenanthroline, (ii) a differential pulse polarographic method based on nitrosation with 0.1 M NaNO₂/dil. HC1 and consequent recording of the differential pulse polarogram. The differential polarogram was obtained under constant amplitude pulses of 50 mV (DP 50) superimposed on a linearly increasing DC-voltage ramp. The peak height (h), of the polarogram was measured at the peak potential of -0.2V on the dropping mercury electrode (DME) versus Ag/AgCl reference electrode. The linearity ranges observed are 0.6μgfml to 6.0μg/ml and 2μg/ml to 12μg/ml, respectively. The mean percentage recoveries for an authentic sample are 99.5±1.4 and 100.5±0.7, respectively. When applied to tablets claimed to contain 10 mg each, the mean percentages obtained are 99.7±2.3 and 100.6 ±1.5 respectively.     

Validation of UV Spectrophotometric Method for Fexofenadine Hydrochloride in Pharmaceutical Formulations and Comparison with HPLC

Abstract

A simple, reproducible, accurate, and effective spectrophotometric method was developed and validated for the quantitation of the antihistamine fexofenadine in capsules and coated tablets. Ethanol was used as solvent and the absorbance at the wavelength of 220 nm was employed to the quantitation of the drug. The method validation was fulfilled through the evaluation of the analytical parameters of linearity, precision, accuracy, limits of detection, and quantitation and specificity. The method was linear (r=0.9999) at concentrations ranging from 8.0 to 20.0 µg ml^?1, precise (RSD intra‐day=0.29; 0.18; 0.39; RSD inter‐day=0.12 for capsules and RSD intra‐day=0.13; 0.16; 0.13; RSD inter‐day=0.13 for coated tablets), accurate (percentage recovery=99.97% for capsules and 100.51% for tablets), sensitive (limits of detection and quantitation of 0.10 and 0.29 µg ml^?1, respectively) and specific. The method was compared to a high performance liquid chromatography (HPLC) method, which was previously developed to the same drug. The results showed no significant difference between the methods in fexofenadine hydrochloride quantitation.