介绍一种特性粘数的测定装置

介绍一种特性粘数测定装置，测定效果好，简便易行。     

3种市售壳聚糖创伤修复类产品的粘均分子量测定

目的测定市面上出售的3种壳聚糖创伤修复类产品的特性粘数,并计算其粘均分子量。方法根据药典规定的乌氏粘度计图解外推法测定其特性粘数〔η〕,利用经验公式推算出粘均分子量M。结果准确且计算方便。结论可以为壳聚糖及其衍生物的分子量测定提供依据。     

胰岛素生物测定方法的比较

通过查阅中、美、英、日四国药典中胰岛素生物测定方法的相关内容,对其历年来的生物活性测定方法进行分析与对比,结果各国药典中胰岛素的生物测定方法还存在差异,胰岛素生物测定方法的发展方向与改进空间应参考国外药典统一为HPLC法。     

六种中成药细菌数和需氧菌总数检测方法的比较

目的：比较同一品种2015版药典需氧菌总数和2010版药典细菌数检测方法的差异。方法：以新癀片、海珠喘息定片、八宝丹锭剂、通脉降脂胶囊、大七厘散以及六味地黄丸六种中成药为研究对象分别按《中国药典》2015版需氧菌总数计数法与《中国药典》2010版细菌计数法进行相应微生物计数方法验证,并对检测方法进行比较。结果：不同版本药典的计数方法学验证过程不尽相同,最终的检测方法也各有差别。 结论：2015版《中国药典》需氧菌总数计数检查法比2010版《中国药典》细菌数计数检查法更为灵敏,并且方法更加合理和更具优越性。     

对药品微生物限度检查中有关细菌数复试问题的讨论

《中国药典》2000年版中规定，药品微生物限度检查时细菌菌落数、霉菌(酵母菌)菌落数超过了该品种微生物限度项下规定时，应从同一批号样品中随机抽样，复试2次，以3次平均值报告。本文就执行《中国药典》2000年版三年来微生物限度检查中，细菌数复试的观察、总结，对细菌数超标是否复试的问题提出了不同看法，供同行商讨。     

藻酸双酯钠治疗高粘血症30例

30例高粘血症患者(男23例,女7例;年龄56±8a)用藻酸双醋钠(PSS)0.15g加5％葡萄糖液500mL,静滴,qd,10d为一个疗程。另30例高粘血症患者(男24例,女6例;年龄52±7a)为对照组,用曲克芦丁0.5g加5％葡萄糖液400mL,静滴,qd,21d为一个疗程。结果:血液流变学改善PSS组明显优于对照组(P<0.01)。     

玻璃酸钠注射液粘度测定及其计算方法的比较

目的:采用日本药典、欧洲药典及中国药典方法对玻璃酸钠注射液进行特性粘数的测定并计算.结论:日本药局方及欧洲药典对特性粘数的测定及计算方法较中国药典严谨,但中国药典的一点法能快速解决生产上测定溶液的特性粘数的要求.     

山梨醇铁物理性质的研究

本文阐述了用红外光谱、电子显微镜、超过滤、凝胶层析、渗透压法等各种技术检测山梨醇铁的物理性质。在700～1100 cm^-1范围内的红外光谱提示β-FeOOH的存在。电子显微镜显示络合物颗粒为球形直径15～30 nm。超过滤和葡聚糖凝胶G 200实验,显示了其分子量的范围和分布。用渗透计测得其分子量(n)为1.7×10⁵,同时得到了其特性粘数与分子量的关系:[η]=3.84×10^-4M^0.47.     

议2010年版中国药典中标准统一的问题

目的探讨2010年版中国药典中使用量和单位以及与其他行业标准、国家标准、国际标准统一问题。方法查找有关标准与中国药典进行比对。结果与结论2010年版中国药典在贯彻执行国家法定计量单位以及有关标准方面不够完善。     

透明质酸钠特性黏度的一点法测定

分别用一点法和多点稀释法测定透明质酸钠的特性黏度,并对测定结果进行比较.结果表明,在保证溶剂和待测溶液的流出时间不小于100s,且相对黏度ηr为130～1.50时,两种方法的测定结果无显著性差异.     

Challenges in Determining Intrinsic Viscosity Under Low Ionic Strength Solution Conditions

Purpose

To determine the intrinsic viscosity of several monoclonal antibodies (mAbs) under varying pH and ionic strength solution conditions.

Methods

An online viscosity detector attached to HPLC (Viscotek®) was used to determine the intrinsic viscosity of mAbs. The Ross and Minton equation was used for viscosity prediction at high protein concentrations. Bulk viscosity was determined by a Cambridge viscometer.

Results

At 15 mM ionic strength, intrinsic viscosity of the mAbs determined by the single-point approach varied from 5.6 to 6.4 mL/g with changes in pH. High ionic strength did not significantly alter intrinsic viscosity, while a significant increase (up to 24.0 mL/g) was observed near zero mM. No difference in bulk viscosity of mAb3 was observed around pH 6 as a function of ionic strength. Data analysis revealed that near zero mM ionic strength limitations of the single-point technique result in erroneously high intrinsic viscosity.

Conclusions

Intrinsic viscosity is a valuable tool that can be used to model baseline viscosity at higher protein concentrations. However, it is not predictive of solution non-ideality at higher protein concentrations. Furthermore, breakdown of numerous assumptions limits the applicability of experimental techniques near zero mM ionic strength conditions. For molecules and conditions studied, the single-point approach produced reliable intrinsic viscosity results at 15 mM. However, this approach must be used with caution near zero mM ionic strength. Data analysis can be used to reveal whether determined intrinsic viscosity is reliable or erroneously high.

     

黏度测定方法的介绍及药典中3个药用辅料黏度测定方法的讨论

黏度是高分子药用辅料的重要物理性质,黏度的测定是高分子药用辅料质量控制的重要手段之一.但在实际工作中,黏度的测定却不象其他理化检测分析方法那样直观稳定.笔者通过对黏度测定一些基本概念的介绍及几国药典中3种药用辅料黏度测定方法的比较,进一步探讨一下黏度测定的相关问题.     

Viscosity of phospholipid sols

The viscosities of lysolecithin sols in water were found to be Newtonian at the concentrations investigated. A Couette viscometer was used. In the mixed sols containing both lysolecithin and lecithin, thixotropy was absent at all ratios and only the sol with a high lecithin fraction showed some non-Newtonian behaviour. The axial ratio of the mixed micelles calculated by the Simha method varies with the lecithin/lysolecithin ratio, rising to a maximum when the phospholipid mixture is of one mole lecithin to two moles lysolecithin. This phenomenon is probably due to the packing of the various hydrophobic groups in the micelle.     

Intrinsic sympathomimetic activity of labetalol

In intact cats, cumulative doses (0.1-10 mg/kg i.v.) of labetalol produced dose-dependent decreases in heart rate and arterial blood pressure and dose-dependently reduced i.v. phenylephrine induced pressor responses. In spinal cats devoid of resting sympathetic tone, labetalol (1 mg/kg i.v.) produced a sustained elevation of heart rate and a transient fall in arterial blood pressure. In reserpine-pretreated, adrenalectomized cats, labetalol produced quantitatively the same effects as in spinal cats, indicating that the cardiovascular effects observed in cats with no resting sympathetic tone are due to a direct action of labetalol rather than via catecholamine release. The elevated heart rate due to labetalol in spinal cats was reduced by subsequent administration of the beta-adrenergic receptor antagonist, propranolol. Further, pretreatment with propranolol prevented the tachycardic and depressor effects of labetalol in spinal cats. In a separate group of spinal cats, labetalol administered in cumulative doses of up to 1 mg/kg i.v., produced graded increases in heart rate and also dose dependently reduced i.v. isoproterenol-induced tachycardic responses. Pindolol, a beta-adrenergic receptor antagonist with partial beta-agonist activity, produced similar effects in spinal cats at cumulative doses of 1-30 micrograms/kg. These results indicate that the alpha- and beta-adrenergic receptor antagonist, labetalol possesses partial beta-adrenergic receptor agonist activity. This intrinsic sympathomimetic action of labetalol appears to be more sustained on cardiac than on vascular beta-adrenergic receptors.     

牙齿隐裂与折裂的本征因素初步分析

目的研究隐裂牙与折裂牙的微观结构特点与发病的内在联系,为隐裂牙预防和临床诊疗提供参考依据。方法以折裂拔除的成人磨牙作为研究对象,利用X射线衍射、扫描电子显微镜和红外反射光谱仪方法,对牙釉质和牙本质的微观结构和形貌分别进行观察和比较分析。结果牙本质与牙釉质的化学成分和晶体结构是一致的,主要组成为羟基磷灰石。但牙本质羟基磷灰石结晶颗粒取向分布比较均匀,且尺寸较小,约为几纳米,而牙釉质羟基磷灰石结晶颗粒高度择优取向,颗粒呈线状,线长度达近百纳米。牙齿裂纹可以出现在牙釉质,也可以出现在牙本质。牙本质中有较高的水含量。结论牙齿隐裂可以出现在牙齿表面,也可以出现在牙齿内部。牙齿隐裂和折裂的直接原因是作用在牙齿上的力,但冷热食物的剧烈刺激,也可以导致牙釉质或牙本质首先出现裂纹。而由牙本质出现的牙齿隐裂,比较难以发现和开展早期治疗,需要特别注意。     

Intrinsic sympathomimetic activity of penbutolol

Summary Six healthy volunteers took part in a randomized, single-blind, crossover study to quantitate the intrinsic sympathomimetic activity (ISA) of penbutolol in comparison with one drug possessing ISA (alprenolol) and with the standard non-ISA drug (propranolol). Single intravenous and one week oral administrations were studied. Complete parasympathetic and sympathetic isolation of the heart was obtained by administration of atropine 0.04 mg/kg body weight i. v. and propranolol 0.4 mg/kg i. v., or corresponding equipotent doses of alprenolol 0.4 mg/kg i. v. and penbutolol i. v. 0.08 mg/kg. In the chronic, oral study propranolol 160 mg b. i. d. was given, or corresponding equipotent doses of alprenolol (400 mg b. i. d.) or penbutolol (40 mg b. i. d.). The test procedure included measurement of heart rate and blood pressure in the supine, sitting and standing positions, and during isometric and dynamic exercise. ISA was calculated by comparison of the change in of heart rate with that produced by propranolol. The ISA of alprenolol was 22–26% and of penbutolol 12–18% of maximal sympathetic activity. Isometric and dynamic exercise gave comparable ISA values.     

乙基纤维素动力黏度测定

使用旋转流变仪测定乙基纤维素的动力黏度.通过试验确定测定温度为(20±0.1)℃,剪切速率为10 s<'-1>.该法简便、准确、重现性好.