羟丙基甲基纤维素对水溶性药物释放的影响

以维生素Ｃ为水溶性药物的模型物，三种不同粘度的羟丙基甲基纤维素制成的凝胶骨架片，以Ｋ１００Ｍ规格对维生素Ｃ的释放有延缓作用。维生素Ｃ民羟丙基甲基纤维素的四种不同比例量制成的凝胶骨架片，其中以１：１的比例量，对维生素Ｃ的释放更缓慢。在凝胶骨架片中含有乳糖时，可加快维生素Ｃ的释放。     

羟丙基甲基纤维素骨架片的水渗透、骨架膨胀和药物释放性质

当HPMC骨架与水接触时,可以观察到水渗透进入HPMC骨架的过程。HPMC取代度类型对水渗透作用的影响集中表现在最初较短的一段时间内,这段时间是指HPMC形成水凝胶的时间。水凝胶形成后,水渗透进入凝胶的速率是恒定的。HPMC对水渗透作用的影响取决于其分子量。当HPMC骨架中加入药物后,水渗透进入骨架的能力会变弱。当水渗透进入HPMC骨架时,骨架可发生明显的膨胀,其轴向膨胀比径向膨胀大得多,骨架的膨胀主要由HPMC产生,骨架中HPMC含量越高,其膨胀程度越大。水渗透、骨架膨胀与药物释放之间存在线性相关性。     

羟丙基甲基纤维素成膜性能的考察

目的：考察羟丙基甲基纤维素的成膜性能。方法：采用正交试验，以不同浓度、不同溶媒为因素，在三水平上进行筛选。结果；以50％乙醇液为溶媒，含10％的羟丙基甲基纤维素液的成膜性能良好。结论：羟丙基甲基纤维素可以作为缓释药膜的成膜材料。     

羟丙基甲基纤维素对茶碱缓释片释放度的影响

利用均匀设计，考察羟丙基甲基纤维素对茶碱缓释片释放度的影响，给出羟丙基甲基纤维素、乳糖与茶碱缓释片释放度的关系．结果表明：用羟丙基甲基纤维素制备的茶碱缓释片，释放度数据较稳定，调整羟丙基甲基纤维素和乳糖量可调节释药速度．片剂硬度较低〔（３．２±０．５）ｋｇ〕和中等〔（６．１±０．９）ｋｇ〕时，对释放度无明显影响，硬度较大〔（１３．０±１．３）ｋｇ〕时，将减缓释药速度．     

羟丙基甲基纤维素在片剂上的应用

随着药物制剂新剂型、新品种的开发,新工艺、新技术的应用和固体制剂质量要求的不断提高,淀粉、糊精等传统的辅料已不能适应发展的需要。此外,要解决片剂的溶出度、崩解时限和生产过程中出现的裂片、粘冲问题以及改进包衣工艺等,光靠传统辅料     

羟丙基甲基纤维素邻苯二甲酸酯的小鼠急性口服毒性试验

目的探讨小鼠口服羟丙基甲基纤维素邻苯二甲酸酯的急性毒性。方法小鼠一日内连续3次灌胃给予羟丙基甲基纤维素邻苯二甲酸酯,观察和记录小鼠的行为、摄食量、体重、呼吸频率和死亡情况,连续观察14d。未死亡小鼠处死后行尸检。结果在日剂量为15g·kg^-1剂量下,小鼠的行为活动无异常,摄食量与对照组相比无明显差异,呼吸频率无改变,仅体重增加比对照组略有下降（P〉0．05）,主要脏器无明显病理改变,观察期内无小鼠死亡。结论羟丙基甲基纤维素邻苯二甲酸酯毒性极低,作为包衣材料安全性高。     

羟丙基甲基纤维素的凝胶特性及其对曲尼司特缓释片释放行为的影响

目的：研究羟丙基甲基纤维素(HPMC)的凝胶特性及其对曲尼司特缓释片释放行为的影响。方法：采用称重法、图像法和体积测量法,研究HPMC辅料片和曲尼司特缓释片在不同pH环境中的水合度和溶胀度。结果：辅料片在SGF和SIF中的水合速率常数分别为0.897 h-1和0.681 h-1;溶胀速率常数分别为1.005 h^-1和0.713 h^-1。曲尼司特缓释片在SGF中,在0.5 h内迅速水合和溶胀,其后呈负增长;而在SIF中,重量和体积都缓慢增加,5 h后重量稍有下降,体积保持不变。结论：HPMC水凝胶的形成速度和形态与介质的pH有关,凝胶层的溶蚀速度控制药物的释放。     

辛伐他汀缓释片制备及体外释放研究

目的 制备辛伐他汀凝胶骨架缓释片,对影响药物释放的因素进行考查。方法 采用紫外分光光度法测定其体外释放度,应用湿法制粒压片法制备缓释片,以羟丙基甲基纤维素(HPMC)为骨架材料,考察了HPMC规格、用量及其它辅料对药物释放的影响,并进行了正交实验优化及处方和制备方法的验证。结果 辛伐他汀缓释片的体外释放受HPMC规格、HPMC用量、粘合剂种类的影响,选择HPMC(K15M)为骨架材料,其与主药质量比为1.5∶1,所制缓释片能持续释药12 h,批间重现性良好。结论 该制剂处方合理,制备方法可行,具有良好的缓释效果。     

Preparation and characterization of hydroxypropyl methyl cellulose films containing stable BCS Class II drug nanoparticles for pharmaceutical applications

The design and feasibility of a simple process of incorporating stable nanoparticles into edible polymer films is demonstrated with the goal of enhancing the dissolution rate of poorly water soluble drugs. Nanosuspensions produced from wet stirred media milling (WSMM) were transformed into polymer films containing drug nanoparticles by mixing with a low molecular weight hydroxylpropyl methyl cellulose (HPMC E15LV) solution containing glycerin followed by film casting and drying. Three different BCS Class II drugs, naproxen (NPX), fenofibrate (FNB) and griseofulvin (GF) were studied. The influence of the drug molecule on the film properties was also investigated. It was shown that film processing methodology employed has no effect on the drug crystallinity according to X-ray diffraction (XRD) and Raman spectroscopy. Differences in aggregation behavior of APIs in films were observed through SEM and NIR chemical imaging analysis. NPX exhibited the strongest aggregation compared to the other drugs. The aggregation had a direct effect on drug content uniformity in the film. Mechanical properties of the film were also affected depending on the drug-polymer interaction. Due to strong hydrogen bonding with the polymer, NPX exhibited an increase in Young's Modulus (YM) of approximately 200%, among other mechanical properties, compared to GF films. A synergistic effect between surfactant/polymer and drug/polymer interactions in the FNB film resulted in an increase of more than 600% in YM compared to the GF film. The enhancement in drug dissolution rate of films due to the large surface area and smaller drug particle size was also demonstrated.     

黄原胶与HPMC的凝胶特性及释药机制

采用直接压片法，研究黄原胶与HPMC的凝胶特性。用称重法和体积测量法研究两种辅料分别在0．1mol／L盐酸和pH6．8磷酸盐缓冲液中的水合度及溶胀度，并以阿莫西林为模型药物进行体外释药研究。结果表明，在0．1mol／L盐酸中，HPMC的水合度及溶胀度均大于黄原胶，对药物释放阻滞作用较大；而在pH6．8磷酸盐缓冲液中则相反。药物在两种辅料中可通过骨架溶蚀和(或)凝胶层扩散呈零级或Higuchi型释药。     

Influence of different types of low substituted hydroxypropyl cellulose on tableting,disintegration, and floating behaviour of floating drug delivery systems

The object of the present study is to evaluate the effect of application of low-substituted hydroxypropyl cellulose (L-HPC) 11 and B1 as excipients promoting floating in gastroretentive tablets. Directly compressed tablets were formed based on experimental design. Face-centred central composite design was applied with two factors and 3 levels, where amount of sodium alginate (X₁) and L-HPC (X₂) were the numerical factors. Applied types of L-HPCs and their 1:1 mixture were included in a categorical factor (X₃). Studied parameters were floating lag time, floating time, floating force, swelling behaviour of tablets and dissolution of paracetamol, which was used as a model active substance. Due to their physical character, L-HPCs had different water uptake and flowability. Lower flowability and lower water uptake was observed after 60 min at L-HPC 11 compared to L-HPC B1. Shorter floating times were detected at L-HPC 11 and L-HPC mixtures with 0.5% content of sodium alginate, whereas alginate was the only significant factor. Evaluating results of drug release and swelling studies on floating tablets revealed correlation, which can serve to help to understand the mechanism of action of L-HPCs in the field development of gastroretentive dosage forms.     

格列吡嗪缓释片的制备及工艺研究

目的 制备格列吡嗪缓释片并对释药因素进行考察.方法 采用湿法制粒工艺,以羟丙甲基纤维素(HPMC)为骨架材料,制备格列吡嗪缓释片;运用正交设计法筛选确定制剂处方;对HPMC规格和用量、稀释剂种类等影响释药的因素进行考察,并在此基础上进行处方筛选.结果 格列吡嗪缓释片的体外释药行为符合Higuchi方程,HPMC用量、H...     

酒石酸美托洛尔缓释片工艺研究

目的对酒石酸美托洛尔缓释片的处方工艺进行研究。方法运用正交设计法,通过测定不同时间酒石酸美托洛尔的释放率,来判断其缓释效果从而对缓释骨架材料、填充剂、粘合剂、润滑剂的种类、规格、用量及工艺等进行考察,并对确定的处方及工艺制备的3批样品测定其释放度。结果用HPMC作为骨架材料,微晶纤维素作为填充剂,硬脂酸镁作为润滑剂,3%EC乙醇溶液作为粘合剂制成酒石酸美托洛尔缓释片。结论本制剂工艺简单,所用各种辅料均为国产化,成本低.制得酒石酸美托洛尔缓释片释放度符合规定。     

Kinetics of Swelling of Compressed Cellulose Matrices: A Mathematical Model

Purpose. A model for swelling time course of compressed cellulose matrix is presented. Methods. The model incorporates the two most important features: water penetration by diffusion and volume change due to swelling. Approximations of the model for small t values and for large t values are also derived, which are utilized in a handy routine for estimation of swelling parameters. Results. The observed time courses of thickness change with compressed matrices of methyl cellulose and hydroxypropyl cellulose agree well with the calculated values of the proposed model. Conclusions. The proposed model is compatible with the observed swelling kinetics.     

托拉塞米对重度心力衰竭的短期临床疗效观察

目的探讨托拉塞米对重度心力衰竭的短期临床疗效及副作用。方法58例重度心力衰竭分为托拉塞米组与呋塞米组,在心衰常规治疗方法相同的情况下,比较两组对心衰患者总有效率、尿量、浮肿消退、血钾、血钠、血Cr变化。结果托拉塞米组总有效率明显优与呋塞米组（93．7％ vs 82．1％P〈0．05）存在显著性差异;尿量（2600ml vs 2100ml）,存在显著差异（P〈0．05）;浮肿消退：托拉塞米组明显消退95．8％,呋塞米组63．6％存在显著差异（P〈0．05）．在每日补钾相同情况下,托拉塞米组血钾上升0．2mmol·L^-1未发生新的低血钾,呋塞米组血钾下降0．1mmol·L^-1低血钾发生率两组存在显著差异（P〈0．05）,两组对血钠、血Cr影响无显著性差异。结论托拉塞米对重度心力衰竭患者有较好的短期疗效、利尿作用强、浮肿消退率高、副作用相对较少。     

Shear and extensional rheology of hydroxypropyl cellulose melt using capillary rheometry

With increasing interest in hot melt extrusion for preparing polymer–drug systems, knowledge of the shear and extensional rheology of polymers is required for the formulation and process design. Shear and extensional rheology of three commercial grades of hydroxypropyl cellulose (HPC) was examined at 140, 145 and 150 °C using twin bore capillary rheometry at range of processing rates. The power law model fitted for shear flow behaviour up to shear strain rates of approximately 1000 s⁻¹, above which measured shear viscosities deviated from the power law and surface instabilities were observed in the extrudate, particularly for higher molecular weight grades. Shear thinning index was found to be relatively independent of temperature and molecular weight, whilst the consistency index, indicative of zero shear viscosity increased exponentially with increase in molecular weight. Extensional viscosity of all grades studied was found to decrease with increasing temperature and increasing processing rate. Foaming of the extrudate occurred especially at low temperatures and with the high molecular weight grade. An understanding of the relationships between shear and extensional flows with temperature, processing rate and molecular weight is a useful tool for process design; optimisation and troubleshooting of Hot melt extrusion (HME) of pharmaceutical formulations.