青霉素钾的单点测定恒温恒湿稳定性试验

目的 建立青霉素钾的单点测定恒温恒湿稳定性试验方法.方法 在恒温和不同湿度及在恒湿和不同温度下进行加速试验,以获得青霉素钾与湿度和温度有关的动力学参数.结果 与经典恒温恒湿法相比,单点测定恒温恒湿稳定性试验大大减少了工作量;与程序变湿变温法相比,只需使用普通的恒温恒湿控制装置.结论 单点测定恒温恒湿稳定性试验可用于湿度对青霉素钾稳定性研究.     

线性降解程序变湿法研究青霉素钾的稳定性

报道了一种新的研究湿度对固体药物稳定性影响的试验方法——线性降解程序变湿法。按照这一变湿规律进行程序变湿药物稳定性试验能最大限度地使药物在高湿和低湿范围内降解程度一致，提高了试验的精密度。作者以青霉素钾为模型药物，采用线性降解程序变湿法和指数程序变温法进行试验，求得了E_a，m，A和t_0.9等动力学参数。结果表明，新方法测定结果的精密度明显优于文献报道的程序变湿变温法。     

台阶变温变湿对阿司匹林稳定性的影响

目的 研究湿度和温度对固体阿司匹林稳定性的影响.方法采用台阶变温变湿加速试验法,通过两次试验获得药物相关的降解动力学参数:一次是在恒温下进行的台阶变湿加速试验,另一次是在恒湿下进行的台阶变温加速试验.结果台阶变温变湿法得到的降解动力学参数为:m=1.19±0.02,Ea= 95.1±1.5 kJ·mol-1,A= (1...     

基于台阶变温变湿法研究温度和湿度对维生素 C稳定性的影响

目的：探索台阶变温变湿加速试验法用于研究温度与湿度对药物稳定性影响的可行性。方法以维生素C为模型药物,通过恒温台阶变湿加速试验和恒湿台阶变温加速试验获得相关的降解动力学参数。结果台阶变温变湿法测得的降解动力学参数：m ＝4．5,Ea ＝111．5 kJ· mol－1,A ＝1．2×1013· h－1;经典恒温恒湿法测得：m ＝4．8,Ea ＝112．3 kJ· mol－1,A ＝8．9×1012 h－1;两者结果基本一致。结论该方法可用于维生素C稳定性的研究,且省时经济,容易操作。     

台阶型变湿变温法对固体哌拉西林钠的稳定性研究

目的建立台阶型变湿变温法对固体药物的稳定性研究方法。方法以哌拉西林钠为模型,采用台阶型变湿变温法研究哌拉西林钠的降解动力学过程。结果得到了哌拉西林钠降解过程的动力学参数A、m及Ea,与经典恒温恒湿法比较,结果一致。结论台阶法可用于哌拉西林钠的降解动力学研究,是否能用于其它固体药物还需进一步研究。     

平面单点测定法研究温度和湿度对阿司匹林稳定性的影响

目的 建立一种研究湿度与温度同时影响药物稳定性的新方法.方法 以阿司匹林为模型药物,利用均匀优化设计分散原理组合所选的温度与湿度水平,以单测点法在组合点下进行稳定性加速试验,从而获得药物与湿度、温度有关的全部动力学参数.结果 所建立的方法与恒温恒湿法和程序变温变湿法得到的降解动力学参数基本一致.与程序变温变湿法相比,其准确度及精密度均高,且只需使用普通的恒温恒湿控制装置;与经典恒温恒湿法比较,能节约时间和样品.结论 平面单点测定法可应用于湿度和温度对药物稳定性的研究.     

青霉素V钾片稳定性考察

目的提高青霉素V钾片的稳定性,延长药品的有效期。方法加入抗氧化剂枸橼酸钠及先进的生产工艺技术,采用双铝包装。结果在湿度75%20℃以下,青霉素V钾片有效期在3.5年以上。结论通过加速试验和长期稳定性试验,降低了青霉素的降解速度,提高了药品的稳定性,延长了青霉素V钾片的有效期。     

程序变温法确定药物降解反应级数

通过电子计算机模拟程序升温加速试验,从理论上阐明了常规的程序升温法不能确定药物降解反应级数的原因是因为同一组数据可由不同的反应级数和活化能的组合所拟合;解决这一问题的关键是在一个变温程序中包含升温和降温部分;据此提出了一种新的程序变温方法(程序升降温法)。利用这种方法,可以真正做到只通过一次程序变温加速试验,就获得包括反应级数在内的药物降解的动力学参数,且确定反应级数的能力与恒温法相近似。     

安乃近的台阶型变温变湿稳定性试验

目的 研究湿度对固体药物稳定性影响的台阶型程序变温变湿法.方法 作者以安乃近为模型药物,采用台阶型程序变湿法和台阶型程序变温法进行试验.结果 求得了Ea、m、A和t0.9,等动力学参数.结论 新方法测定结果较好,操作简单,对仪器要求较低.     

用线性变温法研究扑热息痛溶液和三磷酸腺苷注射液的稳定性

为了提高药品质量,保证药物疗效,研究制剂的稳定性及预测贮存期,对制剂生产是非常必要的。预测药物的稳定性通常在高于室温的条件下进行加速试验。加热加速的方法有两种,一种是恒温法,一种是变温法。近年来国内外对线性变温法研究较多,此法的优点在于只用一套升温装置,通过一次连续     

Evaluation of the stability of aspirin in solid state by the programmed humidifying and non-isothermal experiments

The influence of both moisture and heat on the stability of aspirin was investigated by a single pair of experiments, one with programmed humidity control and the other non-isothermal, rather than many standard isothermal studies, each at constant relative humidity. In experiments, we adopted the acid-base back titration method to measure the content of aspirin in the presence of its degradation products. It was found that the degradation of aspirin could be expressed as ln[(c ₀−c)/c]=kt+D, where D was a lag time item not related to humidity and temperature. The relationship between the degradation rate constant k and humidity H _r and temperature T could be described as Arrhenius equation multiplied by an exponential item of relative humidity: k = A · exp(mH _r ) · exp(−(E _a /RT)), where A, E _a and m were the pre-exponential factor, observed activation energy, and a parameter related to humidity, respectively. The results obtained from the programmed humidifying and non-isothermal experiments, A=(1.09±2.04)×10¹² h⁻¹, E _a =(93.5±2.2) kJ · mol⁻¹ and m=1.18±0.19, were comparable to those from isothermal studies at constant humidity, A=(1.71±0.35)×10¹² h⁻¹, E _a =(94.9±0.7) kJ · mol⁻¹ and m=1.20±0.02. Since the programmed humidifying and non-isothermal experiments save time, labor and materials, it is suggested that the new experimental method can be used to investigate the stability of drugs unstable to both moisture and heat, instead of many classical isothermal experiments at constant humidity.     

Programmed humidifying in drug stability experiments

The stability of penicillin potassium, as a solid state model, was investigated by a programmed humidity and temperature controlled method. An optimization calculational approach to data handling is suggested. The stability of drugs which are unstable to both heat and moisture could be studied by a single pair of experiments, one with programmed humidity control and one non-isothermal, rather than many standard isothermal studies, each at constant relative humidity. The controlling system, based on a pocket computer, was found to be accurate and reliable. The results indicated that the kinetic parameters obtained were comparable to those from isothermal studies.     

盐酸特比萘芬搽剂的稳定性研究

目的考察盐酸特比萘芬搽剂的稳定性。方法通过光照、加速试验、室温留样试验,以HPLC法测定盐酸特比萘芬含量,溶液的外观性状为指标,考察本制剂的稳定性。结果制剂中盐酸特比萘芬在光照实验、加速试验及室温留样试验中含量变化小,含量均在95%以上,外观性状无明显变化。结论HPLC法可快速准确的测定盐酸特比萘芬的含量;盐酸特比萘芬搽剂稳定性好。     

Drying of dosage forms prepared by a humidity technique using a programmed temperature system

Dosage forms prepared using a humidity technique, and consisting of a polymer matrix in which the drug is dispersed, must be dried. The process of drying is rather complex, in the sense that it is controlled not only by evaporation of the vapour out of the surface but also by diffusion of the liquid through the solid. Generally, the diffusivity of the liquid through the polymer as well as the rate of evaporation increases with temperature exponentially. High temperature is able to reduce the time of drying, but a drawback appears with distortion of the shape of dosage forms because of the plasticity of humid beads at high temperature. A programmed temperature process is thus necessary to achieve drying under the best conditions, the rate of heating being a parameter of interest.     

Performance of heated humidifiers with a heated wire according to ventilatory settings.

Delivering warm, humidified gas to patients is important during mechanical ventilation. Heated humidifiers are effective and popular. The humidifying efficiency is influenced not only by performance and settings of the devices but the settings of ventilator. We compared the efficiency of humidifying devices with a heated wire and servo-controlled function under a variety of ventilator settings. A bench study was done with a TTL model lung. The study took place in the laboratory of the University Hospital, Osaka, Japan. Four devices (MR290 with MR730, MR310 with MR730; both Fisher & Paykel, ConchaTherm IV; Hudson RCI, and HummaxII; METRAN) were tested. Hummax II has been developed recently, and it consists of a heated wire and polyethylene microporous hollow fiber. Both wire and fiber were put inside of an inspiratory circuit, and water vapor is delivered throughout the circuit. The Servo 300 was connected to the TTL with a standard ventilator circuit. The ventilator settings were as follows; minute ventilation (V(E)) 5, 10, and 15 L/min, a respiratory rate of 10 breaths/min, I:E ratio 1:1, 1:2, and 1:4, and no applied PEEP. Humidifying devices were set to maintain the temperature of airway opening at 32 degrees C and 37 degrees C. The greater V(E) the lower the humidity with all devices except Hummax II. Hummax II delivered 100% relative humidity at all ventilator and humidifier settings. When airway temperature control of the devices was set at 32 degrees C, the ConchaTherm IV did not deliver 30 mg/L of vapor, which is the value recommended by American National Standards at all V(E) settings. At 10 and 15 L/min of V(E) settings MR310 with MR730 did not deliver recommended vapor, either. In conclusion, airway temperature setting of the humidifying devices influenced the humidity of inspiratory gas greatly. Ventilatory settings also influenced the humidity of inspiratory gas. The Hummax II delivered sufficient water vapor under a variety of minute ventilation.