Hypoglycemic and antioxidative effects of hydroxyethyl methylcellulose in mice fed with high fat diet

The effect of hydroxyethyl methylcellulose (HEMC) with different viscosities on the glucose metabolism and antioxidative defense system in high fat-fed mice was investigated. The mice were randomly divided into five dietary groups: normal control diet (NC), high fat diet (HF), and high fat diet supplemented with high viscosity (HF-HV), moderate viscosity (HF-MV), and low viscosity (HF-LV) HEMC fibers. After 6 weeks, the HF group showed a marked increase in body weight gain, body fat, blood glucose concentration, insulin level, and erythrocyte lipid peroxidation rate relative to the NC group. However, supplementation of HEMC in the diet suppressed these high fat-induced hyperglycemia and oxidative stress through enhancement of the activities of hepatic glucokinase and antioxidant enzymes. The hypoglycemic and antioxidative effects increased with increased viscosity of the HEMC consumed. These results illustrate that HEMC with high viscosity may be useful in the management of high fat diet-induced hyperglycemia and oxidative stress.     

Red algae (Gelidium amansii) hot-water extract ameliorates lipid metabolism in hamsters fed a high-fat diet

The purpose of this study was to investigate the effects of Gelidium amansii (GA) hot-water extracts (GHE) on lipid metabolism in hamsters. Six-week-old male Syrian hamsters were used as the experimental animals. Hamsters were divided into four groups: (1) control diet group (CON); (2) high-fat diet group (HF); (3) HF with GHE diet group (HF + GHE); (4) HF with probucol diet group (HF + PO). All groups were fed the experimental diets and drinking water ad libitum for 6 weeks. The results showed that GHE significantly decreased body weight, liver weight, and adipose tissue (perirenal and paraepididymal) weight. The HF diet induced an increase in plasma triacylglycerol (TG), total cholesterol (TC), low-density lipoprotein cholesterol and very-low-density lipoprotein cholesterol levels. However, GHE supplementation reversed the increase of plasma lipids caused by the HF diet. In addition, GHE increased fecal cholesterol, TG and bile acid excretion. Lower hepatic TC and TG levels were found with GHE treatment. GHE reduced hepatic sterol regulatory element-binding proteins (SREBP) including SREBP 1 and SREBP 2 protein expressions. The phosphorylation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) protein expression in hamsters was decreased by the HF diet; however, GHE supplementation increased the phosphorylation of AMPK protein expression. Our results suggest that GHE may ameliorate lipid metabolism in hamsters fed a HF diet.     

Long-term feeding of red algae (Gelidium amansii) ameliorates glucose and lipid metabolism in a high fructose diet-impaired glucose tolerance rat model

This study was designed to investigate the effect of Gelidium amansii (GA) on carbohydrate and lipid metabolism in rats with high fructose (HF) diet (57.1% w/w). Five-week-old male Sprague-Dawley rats were fed a HF diet to induce glucose intolerance and hyperlipidemia. The experiment was divided into three groups: (1) control diet group (Con); (2) HF diet group (HF); and (3) HF with GA diet group (HF + 5% GA). The rats were fed the experimental diets and drinking water ad libitum for 23 weeks. The results showed that GA significantly decreased retroperitoneal fat mass weight of HF diet-fed rats. Supplementation of GA caused a decrease in plasma glucose, insulin, tumor necrosis factor-α, and leptin. HF diet increased hepatic lipid content. However, intake of GA reduced the accumulation of hepatic lipids including total cholesterol (TC) and triglyceride contents. GA elevated the excretion of fecal lipids and bile acid in HF diet-fed rats. Furthermore, GA significantly decreased plasma TC, triglyceride, low density lipoprotein plus very low density lipoprotein cholesterol, and TC/high density lipoprotein cholesterol ratio in HF diet-fed rats. HF diet induced an in plasma glucose and an impaired glucose tolerance, but GA supplementation decreased homeostasis model assessment equation-insulin resistance and improved impairment of glucose tolerance. Taken together, these results indicate that supplementation of GA can improve the impairment of glucose and lipid metabolism in an HF diet-fed rat model.     

Bioavailability and in vitro oesophageal sticking tendency of hydroxypropyl methylcellulose capsule formulations and corresponding gelatine capsule formulations

The overall aim of the present study was to widen our knowledge about the biopharmaceutical behaviour of novel hydroxypropyl methylcellulose (HPMC)-based two-piece capsules by comparing them with the classic hard gelatine capsules. Firstly, the tendency of the HPMC capsules to stick to isolated porcine oesophageal preparation was evaluated. The force needed to detach the HPMC capsules from the oesophagus was significantly lower than that for the gelatine capsules (P<0.001), which is evidently an advantage of this new dosage form. The second aim was to investigate the possibility of preparing sustained-release capsules using different powdered HPMCs as diluents (K100, K4M and K15M) and the effect of the molecular weight of HPMC powder on the in vitro and in vivo behaviour of the capsules. In addition to peroral drug administration also rectal dosing was applied. Two groups of eight healthy volunteers participated in randomised, cross-over, single-dose studies. One group was administered capsules orally and the other rectally. There were no marked differences in the bioavailability properties of either the oral or rectal HPMC capsules containing ibuprofen as model drug as compared with corresponding gelatine capsule formulations. Using different viscosity grades of HPMC powders as diluents it was possible to control the absorption rate of the model drug both from gelatine and HPMC capsules as far as the oral route was concerned. After rectal administration there were no statistically significant differences between the formulations containing different grades of HPMC powder. Only partial correlation was observed between the results of the bioavailability studies and the in vitro dissolution studies. From a biopharmaceutical point of view these two shell materials can be regarded as interchangeable.     

机械加载对高脂饮食诱导的肥胖和非酒精性脂肪肝的治疗作用

目的 探讨机械加载对高脂饮食诱导的肥胖和非酒精性脂肪肝的疗效。方法 选用6周龄的C57BL/6雌性小鼠30只,体质量约18 g,按随机数字表法分为正常对照组（NC组）、高脂饮食组（HF组）和高脂饮食机械加载治疗组（HF+L组）,每组10只,持续饮食诱导12周。高脂饮食6周后,HF+L组进行机械加载治疗6周。实验动物进行体成分分析,观测全身体脂含量的变化。收集肾周脂肪、子宫周脂肪、肠系膜脂肪、腹股沟脂肪和肝脏并称量湿质量。留取部分肝脏做组织形态学检测,油红O和HE染色分析观察肝脏的病理改变,部分肝脏用于Western blot检测内质网应激相关蛋白（eIF2α、p-eIF2α、ATF4）的表达。结果 与NC组相比,高脂饮食导致HF组体质量、体脂明显增加,机械加载治疗后,HF+L组体质量、体脂较HF组明显降低（P＜0.05）。肝脏组织学结果表明,高脂饮食导致一定程度的肝脏脂肪变性,通过治疗后,脂肪变性得到有效缓解（P＜0.05）。Western blot分析结果表明,高脂饮食导致小鼠肝脏eIF2α、p-eIF2α和ATF4蛋白表达升高,机械加载能够抑制肝脏p-eIF2α和ATF4蛋白的表达。结论 机械加载能够有效缓解高脂饮食导致的体质量、体脂增加及非酒精性脂肪肝,其治疗作用可能与肝脏内质网应激有关。     

Salubrinal通过 eIF2α信号通路治疗非酒精性脂肪肝 #br#

摘要：目的 探讨 Salubrinal对肥胖诱导的非酒精性脂肪肝的疗效。方法 选用 30只雌性 C57BL/6小鼠，随机分 为对照（SCD）组、高脂饮食（HF）组和高脂饮食治疗（HF+S）组。HF组和 HF+S组小鼠给予含脂量为 60%的高脂饮食， 4周肥胖诱导后，HF+S组接受 Salubrinal皮下注射 4周。实验过程中每周测量动物体成分变化，采取静脉血检测血脂 指标，收集皮下、内脏脂肪和肝脏进行湿质量测定。为探索 Salubrinal对肝脏的影响及作用机制，通过 HE、油红 O染 色观察肝脏病理改变，Western blot检测肝组织 eIF2α信号通路相关蛋白 Bip、p-eIF2α、eIF2α、ATF4和 CHOP的表达。 结果 与 SCD组比较，HF组小鼠的血脂水平和脂肪堆积明显增加，Salubrinal治疗后，脂质紊乱情况减轻。同时，肝 脏组织学检查显示，Salubrinal可以明显缓解肝脂肪变性严重程度并抑制异常脂质沉积。此外，Western blot分析表 明，Salubrinal 通过增加 Bip、p-eIF2α/eIF2α 和 ATF4 的表达量，降低 CHOP 的表达水平抑制内质网应激。结论 Salubrinal能够有效缓解肥胖和肝脂肪变性，并通过 eIF2α信号通路调控内质网应激而影响脂质代谢。     

槟榔碱改善2型糖尿病大鼠糖、脂代谢紊乱

目的研究槟榔碱(arecoline)对2型糖尿病大鼠糖、脂代谢的影响及其降糖机制。方法采用高果糖高脂饲料喂养建立2型糖尿病大鼠模型。实验大鼠随机分7组:普通饲料对照组(control),高果糖高脂饲料模型组(HF),高果糖高脂饲料+不同剂量槟榔碱组(1、5、10、20、50mg·kg-1)。观察槟榔碱对糖尿病大鼠血糖、血脂、肝功能及肝脏组织学的影响,采用逆转录-聚合酶链反应(RT-PCR)检测槟榔碱对糖异生酶磷酸烯醇式丙酮酸羧激酶(PEPCK)、葡萄糖-6-磷酸酶(G6Pase)和翼螺旋转录因子O1(FoxO1)、过氧化物酶体增殖物激活受体γ辅激活因子1α(PGC-1α)的mRNA表达的影响。结果与高果糖高脂模型组相比,槟榔碱以剂量依赖的方式降低2型糖尿病大鼠空腹血糖及甘油三脂水平,但是10、20、50mg·kg-1剂量组具有明显肝脏毒性;5mg·kg-1的槟榔碱明显降低糖异生酶PEPCK和G6Pase,转录因子FoxO1及其辅助因子PGC-1α的mRNA的表达。结论低剂量槟榔碱能够改善2型糖尿病大鼠糖脂代谢紊乱,降糖机制为抑制肝脏过度糖异生。     

2208型羟丙甲纤维素功能性相关指标的考察与主成分分析

本文以《中国药典》(2020年版)为指导,对来自进口A厂、国产S厂和国产T厂的2208型羟丙甲纤维素以及同一厂家不同批次的羟丙甲纤维素的功能性相关指标进行了表征,并通过主成分分析对羟丙甲纤维素的功能性相关指标进行全面综合评价。实验结果表明:不同厂家的羟丙甲纤维素黏度和多分散系数(D)未见显著性差异,而样品累积粒度分布百分数达50%时所对应的粒径(d₅₀)、样品累积粒度分布数达90%时所对应的粒径(d₉₀)、松密度(ρ_b)、振实密度(ρ_bt)和卡尔指数等均存在显著性差异。同一厂家不同批次产品各功能性相关指标均存在批间差异,A厂羟丙甲纤维素粒径的批间差异最大,多分散系数批间差异次于S厂,其他指标的批间差异均小于国产厂家。通过主成分分析提取出方差贡献率达89.44%的3个主成分。再通过构建综合评价模型,得到羟丙甲纤维素的综合得分排序:S厂>A厂>T厂。     

Anti‐contractile effects of perivascular adipose tissue in thoracic aorta from rats fed a high‐fat diet: role of aerobic exercise training

The aim of the present study was to evaluate the effects of aerobic exercise training on perivascular adipose tissue (PVAT) function in thoracic aorta from rats fed a high‐fat diet. Aortic vascular reactivity was performed in sedentary (SD), trained (TR), sedentary high‐fat diet (SD‐HF), and trained high‐fat diet (TR‐HF) male Wistar rats in the absence (PVAT?) or in the presence (PVAT+) of thoracic PVAT. We also measured circulatory concentrations of leptin and tumour necrosis factor alpha (TNF‐α), as well as the protein expressions of TNF‐α receptor 1 (TNFR1) and inducible nitric oxide synthase (iNOS) on PVAT. In the SD‐HF group, the body weight, epididymal fat pad, thoracic PVAT, circulatory triglycerides, insulin, leptin and TNF‐α were increased when compared with the SD group, whereas exercise training reduced these values in TR‐HF group. The relaxing response curves to acetylcholine and sodium nitroprusside were not modified by either intervention (high‐fat diet or exercise training) or the presence of PVAT. The presence of PVAT had an anti‐contractile effect in response to serotonin in all groups. In SD‐HF group, the increased magnitude of anti‐contractile effects was in parallel with an up‐regulation of iNOS protein expression in PVAT without alteration in TNFR1. Exercise training was effective in normalizing the vascular reactivity in rings PVAT+ and in reducing the iNOS protein expression. Exercise training prevented the PVAT–induced alteration in thoracic aorta from rats fed a high‐fat diet.     

Safety assessment of hydroxypropyl methylcellulose as a food ingredient

Hydroxypropyl methyl cellulose (HPMC; CAS No. 9004-65-3) is an odorless and tasteless, white to slightly off-white, fibrous or granular, free-flowing powder that is a synthetic modification of the natural polymer, cellulose. It is used in the food industry as a multipurpose food ingredient. HPMC is approved by FDA as both a direct and an indirect food additive, and is approved for use as a food additive by the EU. The JECFA has evaluated the food uses of HPMC and established an acceptable daily intake (ADI) of ‘not specified’ for such uses. Based on the no-observed-adverse-effect level (NOAEL) of 5000 mg/kg body weight/day from a 90-day feeding study in rats, a tolerable intake for ingestion of HPMC by humans of 5 mg/kg body weight/day is posited and, as such, is more than 100-fold greater than the estimated current consumption of 0.047 mg/kg body weight/day.     

二氢杨梅素经激活SIRT1-AMPK通路抑制高脂饮食诱导的肥胖小鼠肝脏脂质沉积

目的探究二氢杨梅素(dihydromyricetin,DHM)对高脂饮食诱导的肥胖小鼠肝脏脂质蓄积的作用及其机制。方法C57BL/6J小鼠60只,随机分为6组(n=10):①ND组:正常饲料;②ND+L-DHM组:正常饲料+低剂量DHM(125 mg·kg^-1·d^-1);③ND+H-DHM组:正常饲料+高剂量DHM(250 mg·kg^-1·d^-1);④HFD组:高脂饲料;⑤HFD+L-DHM组:高脂饲料+低剂量DHM;⑥HFD+H-DHM组:高脂饲料+高剂量DHM。记录小鼠体重;16周后,测空腹血脂;计算体脂重量;肝脏HE和油红O染色;荧光定量PCR和Western blot检测肝脏SIRT1、AMPK、ACC、FAS、SREBP-1和PPARα、CPT1的表达。结果与ND组相比,HFD组小鼠体重、体脂、血清TG、TC、HDL水平明显增加;肝脏内脂肪蓄积增加,肝脏SREBP-1c、FAS、ACC1表达增加,而PPARα、CPT1、SIRT1和AMPK表达下降。经DHM处理后,HFD小鼠上述指标发生逆转;但ND小鼠上述指标无明显改变。结论DHM可能通过激活SIRT1-AMPK通路抑制脂质合成,促进脂质分解,改善高脂饮食诱导的肥胖小鼠肝脏脂质沉积。     

机械加载改善高脂饮食诱导的肥胖相关骨丢失

目的 探究脉冲式关节机械加载对高脂饮食诱导的肥胖小鼠骨丢失的改善作用。方法 将 45只雌性C57BL/6小鼠随机分为普通饮食对照组（Sham组）、高脂饮食模型组（HF组）和高脂加载治疗组（HF+L组）,每组 15只。HF组和 HF+L组高脂饮食喂养 4周后,HF+L组进行 4周的机械加载治疗（加载条件为 1 N,10 Hz,3 min/d,每周连续加载 5 d）。治疗结束后测量 3组小鼠体质量指数（BMI）、全身体脂含量和双侧股骨的骨密度。使用 HE染色和MacNeal’s染色分析观察股骨的组织病理改变,使用 Western blot检测成骨生成相关蛋白［碱性磷酸酶（ALP）、Runt相关转录因子 2（RUNX2）］和脂肪生成相关蛋白［过氧化物酶体增殖物激活受体 γ（PPARγ）、CCAAT/增强子结合蛋白 α（C/EBPα）］的表达。结果 与 Sham组相比,HF组小鼠的体脂含量和 BMI升高,骨密度变化率和骨量变化率显著下降,骨小梁面积明显减少,骨髓脂肪细胞增多。机械加载治疗后,HF+L组的骨密度、骨小梁面积比 HF组明显升高,脂肪细胞的数目和面积比 HF 组显著降低（P＜0.05）。Western blot 分析结果表明,HF+L 组与 HF 组相比,ALP 和RUNX2的表达显著升高,C/EBPα和 PPARγ的表达明显降低（均P＜0.05）。结论 机械加载能够有效缓解由肥胖引起的低骨密度和低骨量,其治疗作用可能通过促进成骨分化和抑制脂肪生成来改善骨丢失。     

1-Deoxynojirimycin isolated from Bacillus subtilis improves hepatic lipid metabolism and mitochondrial function in high-fat–fed mice

The aim of this study was to determine whether 1-deoxynojirimycin (DNJ) isolated from Bacillus subtilis MORI beneficially influences lipid metabolism and mitochondrial function in the liver of mice fed a high-fat diet in addition to the anti-obesity properties of DNJ. Male C57BL/6 mice (n = 29; 5 weeks old) were randomly assigned to three groups: normal control diet (CTL, n = 10), high-fat diet (HF, n = 10), and high-fat diet supplemented with DNJ (DNJ, n = 9). After 12 weeks, the HF group exhibited higher overall weight gain, of the liver, and of various fat pads than the CTL and DNJ groups did. The HF group also showed greater expression of C/EBPα and CD36 mRNA in the liver than that in the CTL and/or DNJ groups. In addition, mRNA expressions of AAC and FAS were lower, while mRNA expression of PGC-1β was higher in the liver of the DNJ group than that of the HF group. The hepatic expression of p-AMPK/AMPK was higher in the DNJ group than in the HF group. This study provides novel insight into the protective effect of DNJ supplementation against obesity-induced hepatic lipid abnormalities and mitochondrial dysfunction.     

Gamma scintigraphic evaluation of the fate of hydroxypropyl methylcellulose capsules in the human gastrointestinal tract

The fate (movement and disintegration) of hard novel hydroxypropyl methylcellulose (HPMC) two-piece capsules in the human gastrointestinal tract was investigated using a gamma scintigraphic imaging method. Two different prolonged-release formulations without an active ingredient were used. The capsules contained different viscosity grades of HPMC powder (HPMC K100 and HPMC K4M). The aim was to determine the main reason why the pharmacokinetic profiles of model drugs change when the diluent was changed to a higher viscosity grade. The results were compared with our previous pharmacokinetic studies with corresponding capsules containing metoclopramide hydrochloride or ibuprofen as a model drug. The first observation was that the HPMC capsules had a tendency to attach to the oesophagus. Therefore, it is recommended that the HPMC capsules as well as gelatine capsules be taken with a sufficient amount of water (150–200 ml) in an upright position and maintaining the upright position for several minutes. The viscosity grade of the HPMC did not affect the transit times of the capsules in the GI tract. The major differences between the two formulations were the complete disintegration times of the capsules and the spreading of the capsules to the large intestine. Most of the HPMC K100-based capsules were completely disintegrated during the 8 h study, whereas the HPMC K4M-based capsules still exhibited plug formations in the large intestine. Also the HPMC K100-based capsules spread better to the ascending colon than the HPMC K4M-based capsules. The faster disintegration of the HPMC K100-based capsules explains the differences in the pharmacokinetic profiles of the model drugs between the HPMC K100- and K4M-based capsules in our previous studies. The main absorption site of the drugs from the capsules studied here is probably the large intestine when taken in a fasting state.     

Stabilization of Misoprostol with Hydroxypropyl Methylcellulose (HPMC) Against Degradation by Water

The stability of misoprostol oil is significantly improved in a hydroxypropyl methylcellulose (HPMC) dispersion (1:100). In order to assess the effect of water on misoprostol stability, the rate of misoprostol degradation was investigated in the misoprostol/HPMC dispersion at 55°C, along with the water sorption isotherm, under seven different relative humidity (RH) conditions ranging from 0 to 81%. The results indicated that the first-order rate constants of misoprostol degradation increased in a concave-up fashion as the water content of the dispersion increased. Below 30% relative humidity (2% water), the first-order rate constants of misoprostol degradation were found to be minimum. The results of the stability study were interpreted in terms of the changing structure of HPMC as it related to the mobility of water and misoprostol within the HPMC dispersion.     

非诺贝特和罗格列酮对大鼠血脂、体重和胰岛素敏感性的作用比较

目的 :比较非诺贝特、罗格列酮对大鼠胰岛素敏感性、血脂、体重的影响。方法 :32只大鼠随机分为 4组 ,1组给予普通饲料 ,其余 3组给予高脂饲料喂养 ,制作胰岛素抵抗模型。 4wk后取高脂饲料喂养的 2组大鼠予非诺贝特 (10 0mg·kg- 1·d- 1)、罗格列酮 (8mg·kg- 1·d- 1)灌胃 ,其他 2组予安慰剂灌胃。结果 :给高脂饲料的 3组大鼠体重、血脂和胰岛素水平均明显增高 (P <0 .0 1)。给药后 ,非诺贝特组和罗格列酮组大鼠游离脂肪酸均降低 ,非诺贝特组血清三酰甘油降低 ,与高脂对照组对比差异有显著意义 [(0 .84±s0 .18)mmol·L- 1vs (1.2±0 .3)mmol·L- 1,P <0 .0 5 ]。非诺贝特组体重增长幅度减小 ,罗格列酮组体重增长幅度增加。 2种药物都能增加葡萄糖输注率 ,罗格列酮作用优于非诺贝特。结论 :非诺贝特可降低大鼠血脂、减少体重、有适度的胰岛素增敏作用。罗格列酮具有良好增敏作用及适度的降脂作用 ,可引起体重增加     

Structure and hydration properties of hydroxypropyl methylcellulose matrices containing naproxen and naproxen sodium

The present study was conducted to obtain a deeper insight into the mechanism of drug release from HPMC matrices. The microstructure, mobility, internal pH and the state of water within the gel layer of hydrated HPMC matrices (having different molecular weights) containing naproxen sodium (NS) and naproxen (N) were studied using Electron Paramagnetic Resonance (EPR), Nuclear Magnetic Resonance (NMR) and Differential Scanning Calorimetry (DSC) techniques. The study show that matrices composed of various viscosity grades of HPMC are characterized by similar microviscosity values in spite of the difference in their molecular weight. The NMR and DSC results led to the conclusion that higher molecular weights of HPMC are characterized by higher water absorption capacity and higher swelling. Analysis of non-freezable water in HPMC(K4M)–NS system revealed that addition of NS to solution increased the fraction of water bound to K4M+NS compared with the equivalent solutions without NS. The results suggest that the drug is participating in the crystallization of water and leads to the formation of a three dimensional network structure that decreases the freedom of water in K4M+NS samples. Calculation of the number of hydration shells showed that up to 2.2 layers are involved in HPMC-NS hydration compared to 1.5 layers for HPMC gel without NS. This was explained based on the different water ordering in the gel induced by NS as results of its absorption to polymer surface. Microviscosity values measured by EPR for K4M/N and K4M/NS hydrated matrices were found to be higher for K4M/N matrices, especially at initial stage of hydration. Mobile compartment calculations showed lower values for K4M/N compared with K4M/NS matrices. pH measurements by EPR revealed that incorporation of N to HPMC matrix led to lower internal pH value inside the hydrated tablet compared with NS. This behavior led to lower solubility of N which dictates its surface erosion mechanism, compared with NS matrix that was characterized by higher internal pH value and higher drug solubility. These properties of HPMC/NS increased chain hydration and stability, and led to drug release by the diffusion mechanism.     

A compaction process to enhance dissolution of poorly water-soluble drugs using hydroxypropyl methylcellulose

The purpose of this study was to develop a technique to enhance the dissolution rate of poorly water-soluble drugs with hydroxypropyl methylcellulose (HPMC) without the use of solvent or heat addition. Three poorly water-soluble drugs, naproxen, nifedipine, and carbamazepine, were studied with low-viscosity HPMC USP Type 2208 (K3LV), HPMC USP Type 2910 (E3LV and E5LV), and methylcellulose. Polymer and drug were dry-blended, compressed into slugs on a tablet press or into ribbons on a roller compactor, and then milled into a granular powder. Dissolution testing of the milled powder was performed on USP Apparatus II, 100 rpm, 900 ml deionized water, 37 degrees C. Drug distribution vs. particle size was also studied. The compaction processes enhanced drug dissolution relative to drug alone and also relative to corresponding loosely mixed physical mixtures. The roller compaction and slugging methods produced comparable dissolution enhancement. The mechanism for dissolution enhancement is believed to be a microenvironment HPMC surfactant effect facilitated by keeping the HPMC and drug particles in close proximity during drug dissolution. The compaction methods in this study may provide a lower cost, quicker, readily scalable alternative for formulating poorly water-soluble drugs.     

A three-month repeated oral administration study of a low viscosity grade of hydroxypropyl methylcellulose in rats

The toxicity of the lowest viscosity grade of hydroxypropyl methylcellulose (HPMC) that is currently commercially available was investigated by means of a three-month repeated oral administration study in male and female Crj:CD (SD) IGS rats at doses of 505, 1,020 and 2,100 mg/kg/day. Body weights of males and females in the 2,100 mg/kg group were lower than those of the control group on and after day 28 of administration, but the differences were not statistically significant. The degree of suppression of body weight gain in males was higher than that in females. This tendency was similar to the results in other toxicity studies of HPMC that have been reported. Males in the 2,100 mg/kg group showed a tendency (not significant) for decreased food consumption and urine volume. Examinations of general signs, hematology, blood chemistry, ophthalmology, absolute and relative organ weights, autopsy and histopathology revealed only a few, apparently coincidental, statistically significant differences from the control, and no evidence of any dose-dependent changes was found. It was concluded that the lowest viscosity grade of HPMC showed extremely low toxicity under the conditions of this study, as has been found for higher viscosity grades.     

高脂诱导性肥胖大鼠的胰岛素敏感性与TNF-α及FFAs水平

目的观察正常大鼠在高脂饮食诱导下形成肥胖后的胰岛素敏感性及其TNF-α、FFAs的变化。方法9周龄健康雄性Wistar大鼠16只,随机分为正常饲养组(NC熏n=8)和高脂饲养组(HF熏n=8)。喂养10周,比较两组大鼠体重、胰岛素抵抗指数(HOMA-IR)、以及TNF-α、FFAs等的变化。结果经10周高脂喂养,HF组与NC组比较,体重和内脏脂肪组织显著增加(HF组大鼠体重较NC组增加了11.4%,P<0.05;HF组大鼠内脏脂肪组织较NC组增加了20.7%,P<0.01),并出现胰岛素抵抗(HOMA-IR:HF组为8.88±4.25,NC组为3.92±2.26熏P<0.05),空腹FFAs和TNF-α水平显著上升,较NC组分别增加了80.8%(P<0.05)和58.4%(P<0.05),但两组空腹血糖差异无显著性(HF组为7.89±1.46mmol/L,NC组为8.70±1.59mmol/L熏P>0.05)。结论高脂饮食可诱导大鼠肥胖伴胰岛素抵抗,其胰岛素抵抗的形成可能与TNFα、FFAs水平的升高有关。