HPLC法测定聚乳酸-乙醇酸载药支架上雷帕霉素的载药量

目的:建立测定聚乳酸-乙醇酸载药支架上雷帕霉素载药量的方法。方法:采用高效液相色谱法。色谱柱为Amthyst C18,流动相为乙腈-水(90∶10,V/V),流速为0.8 ml/min,检测波长为277 nm,柱温为40℃,进样量为20μl。结果:雷帕霉素的质量浓度在59.04~157.44μg/ml范围内与其峰面积呈良好的线性关系(r=0.999 6);精密度、稳定性、重复性试验的RSD分别为1.2%、2.72%、0.81%;平均加样回收率为102.85%,RSD为0.91%(n=9)。结论:本方法操作简单、准确可靠,可用于测定聚乳酸-乙醇酸载药支架上雷帕霉素的载药量。     

两种释放速度雷帕霉素涂层支架预防支架内再狭窄的动物实验

目的　评价两种不同药物释放速度雷帕霉素涂层支架抑制血管新生内膜的作用和预防支架内再狭窄的有效性及安全性。方法　采用随机、双盲和对照的试验方法 ,在 2 0头微型猪的冠状动脉前降支或左旋支分别置入支架 (金属裸支架 8枚为对照组 ,雷帕霉素涂层 6 5～ 90 μg/支架 5枚为缓释组 ,6 8～ 96 μg/支架 7枚为快释组 ,2 8d后进行冠脉造影 (CAG) ,术后处死动物 ,取出支架血管 ,进行组织学分析。结果　再狭窄率对照组 2 5 % (2 / 8) ,两雷帕霉素涂层支架组均为 0 %。冠脉造影平均狭窄程度缓释组和快释组较对照组分别减少 90 3%和 74 2 % (均P <0 0 5 ) ,两组间无显著差异 ;缓释组和快释组较对照组新生内膜面积显著减少 (1 0 9mm2 、1 2 4mm2 与 2 18± 1 0 3mm2 ,均P <0 0 5 ) ,两组间相比无统计学意义。结论　两种不同释放速度的雷帕霉素涂层支架均可有效减少血管内新生内膜面积 ,明显降低支架内再狭窄程度 ,两组之间作用相同且应用安全。     

雷帕霉素药物支架稳定性试验研究

目的对雷帕霉素涂层支架在室温下的贮存稳定性进行研究,以确定其有效期。方法将3个批号的产品放置于恒温培养箱内,设定不同温度,测定不同时间的药物含量、药物纯度、聚合物分子量、体外释放、无菌、球囊性能等。结果在稳定性研究的15个月时间内,各项检测指标符合标准。结论本文进行的产品稳定性研究数据可以作为本品的有效期及贮存方法的确立依据。     

阿奇霉素缓释阴道栓的质量控制

目的:对阿奇霉素缓释阴道栓进行质量控制。方法:采用薄层色谱法(TLC)鉴别阿奇霉素缓释阴道栓中的阿奇霉素,用反相高效液相色谱法测定其中阿奇霉素的含量;以pH6.0磷酸盐缓冲液为释放介质,采用《中国药典》2005年版二部释放度测定法中的第一法测定累积释放率并进行体外释药模型的拟合。结果:TLC鉴别方法专属性强,阿奇霉素检测浓度线性范围为50～800μg·mL~(-1)(r=0.9998);平均回收率为100.56%,RSD<1.84%(n=6);体外释放模型符合Higuchi方程。结论:所建立的阿奇霉素缓释阴道栓质量控制方法可靠、准确、专属性强,且制剂的体外释放符合缓释标准。     

流通池法测定甲硝唑口腔粘贴片的释放度

摘要：目的:建立测定甲硝唑口腔粘贴片释放度的方法,并对不同公司样品测定的释放曲线进行比较。方法:采用流通池法闭环系统,以磷酸盐缓冲液(p H 6.6)为溶出介质,流速为4 ml·min-1,在规定时间点取样后采用HPLC法测定。比较不同公司样品在流通池法和篮法下的释放度。结果:甲硝唑在6.024～100.400μg·ml-1浓度范围内线性关系良好(r=0.999 9),平均回收率为99.5%,RSD为0.48%(n=9)。经Weibull方程拟合后,不同公司样品测定的释放度拟合参数差异有统计学意义(P<0.01)。结论:不同公司甲硝唑口腔粘贴片的释放度存在差异,本法可用于甲硝唑口腔粘贴片的释放度检查。     

流通池法测定复方酮康唑乳膏释放度的方法研究

目的:建立适用于复方酮康唑乳膏的释放度检查方法。方法:采用流通池法测定复方酮康唑乳膏的释放度,释放介质为0.01 mol·L~(-1)盐酸溶液,流速为8 mL·min~(-1);以 HPLC 测定释放量,使用 Symmetry C_(18)柱(3.9 mm×150 mm,5 μm),流动相0.02 mol·L~(-1)磷酸氢二钠溶液-甲醇(25:75,用磷酸调节 pH 至6.9±0.1),流速1 mL·min~(-1);检测波长为225 nm。结果:酮康唑在0.3～18μg·mL~(-1)浓度范围内线性良好(r=0.9999);平均回收率(n=9)为99.8%,RSD 为0.67%。同一厂家的复方酮康唑乳膏释放曲线稳定,在24 h 内释放药物超过65%;不同厂家的复方酮康唑乳膏释放曲线不同。结论:本方法可用于复方酮康唑乳膏的释放度检查,对于药物乳膏的质量控制具有指导意义。     

雷帕霉素药物涂层支架治疗冠心病疗效评价

目的评价雷帕霉素药物涂层支架(CYPHER,Cordis)对冠心病的早期治疗效果。方法2002年12月至2004年10月38例冠心病患者置入CYPHER支架(38枚,药物支架组),随机选择同期38例接受普通、非药物涂层支架治疗(40枚,裸支架组),比较两组支架置入情况及早期临床事件发生率。结果两组间临床资料、冠脉病变的程度和分型差异无统计学意义,两组支架平均长度相似,但药物支架组平均支架直径较裸支架组显著减少。两组手术成功率相似(100%∶99·0%,P>0·05)。平均随访(5·0±3·1)个月,随访率98·7%,药物支架组心绞痛复发率显著低于裸支架组(5·2%∶23·7%,P<0·01)。结论冠心病患者应用雷帕霉素药物涂层支架治疗早期临床效果优于普通标准支架。     

阿奇霉素缓释干混悬剂释放度测定及Beagle犬体内外相关性评价

目的进行阿奇霉素缓释干混悬剂体外释放度的测定及比格犬体内外相关性评价。方法按2010版中国药典释放度测定法测定阿奇霉素缓释干混悬剂体外释放度,用液相色谱-串联质谱(LC/MS/MS)法测定阿奇霉素在比格犬体内的血药浓度,并用WinNonlin Professional v5.2进行数据处理。结果以体内吸收分数(fa)对体外累积释放度(F)进行线性回归,得方程fa=1.1553F-52.931(r=0.9475)。结论体内吸收分数与体外累积释放度具有良好的相关性,阿奇霉素缓释干混悬剂所采用的释放度测定方法合理,可以较好反映体内吸收情况。     

RP-HPLC法测定丙戊酸钠缓释片的释放度

目的:建立测定丙戊酸钠缓释片释放度的反相离子对色谱法,并与已有滴定方法进行比较。方法:采用SHIMADAZU VPC18色谱柱,以0.12%四丁基氢氧化铵缓冲液(含0.02 mol.L-1磷酸二氢钾,用10%磷酸调节pH值至6.0)-甲醇(50∶50)为流动相,流速1.0 mL.min-1,检测波长207 nm。结果:HPLC法测定丙戊酸钠在50～600μg.mL-1浓度范围内线性关系良好r=0.999 9,平均回收率为99.7%(n=9),RSD为0.4%。测定3批样品结果HPLC法与《中国药典》的滴定方法无显著性差异。结论:所建方法准确、方便,可作为丙戊酸钠缓释片释放度的药典测定方法。     

呋喃妥因片释放度测定方法

目的:建立呋喃妥因片的释放度测定方法.方法:按2000年版<中国药典>附录释放度测定法[附录XD第二法(2)],采用溶出度测定法第二法装置,在酸中,以0.1 mol/mL盐酸溶液为溶剂;在缓冲盐中,以磷酸盐缓中液(pH=7.2)为溶剂;转速150 r/min;用紫外分光光度计检测,测定波长为375 nm.结果:呋喃妥因片的浓度在1.041～10.41μg/mL范围内与吸收度呈良好线性关系(r=0.999 99).平均回收率为100.9%,RSD=0.77%(n=9).结论:所用方法简单、准确,能有效的控制呋喃妥因片的质量.     

Augmentation of SR Ca(2+) release by rapamycin and FK506 causes K(+)-channel activation and membrane hyperpolarization in bladder smooth muscle

1. The immunosuppressants rapamycin and FK506 are known to relax smooth muscle despite facilitating Ca(2+) release through ryanodine-receptors of the sarcoplasmic reticulum (SR). The apparent contradiction was studied in isolated guinea-pig urinary bladder myocytes. 2. Modulation of spontaneous SR Ca(2+) release was monitored by means of spontaneous transient outward currents (or STOCs) in isolated smooth muscle cells voltage-clamped to -20 mV. Rapamycin (10 microM, n=18) significantly increased amplitude (50+/-12%, mean+/-s.d.), life time (77+/-19%), and time integral of STOCs (113+/-22%), and it reduced the interval between STOCs (20+/-7%). FK506 (20 microM, n=24) increased amplitude (15+/-7%), life time (50+/-7%), time integral (104+/-26%). Cyclosporin A (20 microM, n=18) had no significant effects on STOCs. 3. The basal cytoplasmic Ca(2+) concentration ([Ca(2+)](c)) measured by Indo1-fluorescence was insensitive to rapamycin or FK506. Pretreatment with rapamycin (20 microM, 2 min) did not impair the SR Ca(2+) load as can be concluded from caffeine-induced Ca(2+)-transients. 4. As it was expected from the enhanced STOC activity, the non-clamped membrane was hyperpolarized by rapamycin (15+/-2 mV) or by FK506 (15+/-3 mV). 5. The data are consistent with the idea that rapamycin and FK506 augment spontaneous SR Ca(2+) release by removal of FK-binding proteins from the RyR-complex. Smooth muscle relaxation is interpreted as negative Ca(2+) feedback: augmented Ca(2+) activation of STOCs induces membrane hyperpolarization that reduces Ca(2+) influx through voltage gated channels.     

Effect of relative humidity on drug release from phenytoin sodium tablets and capsules. Part 1: Commercial preparations

In this study the release rate of the active substance from different lots of commercial tablets and capsules of phenytoin sodium kept in different relative humidities (56, 75, 95%) was studied. It was observed that in both tablets and capsules, the effect of relative humidity and ageing was evident on the in vitro dissolution rate when compared with the in vitro dissolution profiles obtained before storage. The release rate differed from one lot to another after storage, the lots with higher release rates before storage in general showing a decrease and the ones with lower dissolution rates showing a higher release rate after storage.     

Poly(ethylene glycol)-block-poly(2-methyl-2-benzoxycarbonyl-propylene carbonate) micelles for rapamycin delivery: in vitro characterization and biodistribution

Our objective was to synthesize an amphiphilic diblock copolymer for micellar delivery of rapamycin. Poly(ethylene glycol)-block-poly(2-methyl-2-benzoxycarbonyl-propylene carbonate) (PEG-b-PBC) with different hydrophobic core lengths were synthesized from methoxy poly(ethylene glycol) and 2-methyl-2-benzoxycarbonyl-propylene carbonate through ring-opening polymerization using 1,8-diazabicycloundec-7-ene as a catalyst. The critical micelle concentration of PEG-b-PBC was around 10(-8) M and depends on the hydrophobic core length. Rapamycin was effectively incorporated into micelles and drug loading increased with increasing hydrophobic core length, with maximal drug loading of 10% (w/w, drug/polymer), drug loading efficiency of about 85%, and mean particle size of around 70 nm. The drug release profile was also dependent on the hydrophobic core length and the drug release from PEG(114) -b-PBC(30) micelles was the slowest. We also determined the toxicity of rapamycin micelles on insulinoma (INS-1E) β-cells and human islets. Encapsulation of rapamycin into PEG-b-PBC micelles reduced its toxicity. Biodistribution of rapamycin-loaded PEG-b-PBC micelles was determined after systemic administration into mice. Rapamycin-loaded PEG-b-PBC micelles showed little difference in pharmacokinetics and biodistribution characteristics in mice compared with rapamycin carrying nanosuspension. In conclusion, rapamycin formulated with PEG-b-PBC micelles showed significantly reduced toxicity on INS-1E β-cells and human islets, but had similar biodistribution profiles as those of nanosuspensions.     

Potency evaluation of antivenoms in Brazil: the national control laboratory experience between 2000 and 2006.

Envenoming from snakebites is an important public health issue in Brazil. In 2005, 28,597 cases were notified (15 cases/100,000 inhabitants), 87.5% due to Bothrops and 9.2% to Crotalus genus. Antivenoms available in Brazil are liquid preparations containing purified equine Fab'2. Since 1987, the National Institute for Quality Control in Health (INCQS/FIOCRUZ) has been testing all lots prior to batch release. Between 2000 and 2006, 619 lots of antivenoms were tested, comprising 2,513,690 ampoules. The potency assay was performed only for bothropic and crotalic antivenoms (485 lots corresponding to 1,866,726 ampoules) due to the unavailability of the other reference venoms. This paper aims to report the last 7-year activities of INCQS on the quality control, batch release and potency evaluation of antivenoms.     

Cyclic ADP-ribose requires FK506-binding protein to regulate intracellular Ca2+ dynamics and catecholamine release in acetylcholine-stimulated bovine adrenal chromaffin cells

The present study was undertaken to elucidate whether cyclic ADP-ribose (cADPR) mediates the amplification of Ca2+ signaling and catecholamine release via the involvement of FK506-binding proteins (FKBPs)/ryanodine receptor (RyR) in bovine adrenal chromaffin cells. cADPR induced Ca2+ release in digitonin-permeabilized chromaffin cells and this was blocked by FK506 and rapamycin, ligands for FKBPs; 8Br-cADPR, a competitive antagonist for cADPR; and antibody for FKBP12/12.6, while it was enhanced by cyclosporin A. Ryanodine-induced Ca2+ release was not affected by 8Br-cADPR and was remarkably enhanced by FK506, rapamycin, cyclosporin A, and cADPR. FK506 binds to FKBP12.6 and removes it from RyRs, but cADPR did not affect the binding between FKBP12.6 and RyR. In intact chromaffin cells, 8Br-cADPR, FK506, and rapamycin, but not cyclosporin A attenuated the sustained intracellular free Ca2+ concentration ([Ca2+]i) rise induced by acetylcholine (ACh). 8Br-cADPR, FK506, and SK&F 96365 reduced the Mn2+ entry stimulated with ACh only when Ca2+ was present in the extracellular medium. 8Br-cADPR, FK506, and rapamycin concentration-dependently inhibited the ACh-induced catecholamine (CA) release. Here, we present evidence that FKBP12.6 associated with RyR may be required for Ca2+ release induced by cADPR in bovine adrenal chromaffin cells. cADPR-mediated Ca2+ release from endoplasmic reticulum in ACh-stimulated chromaffin cells is coupled with Ca2+ influx through the plasma membrane which is essential for ACh-stimulated CA release.     

Allicin release under simulated gastrointestinal conditions from garlic powder tablets employed in clinical trials on serum cholesterol

The failure of five recent clinical trials to show significant reduction in elevated serum cholesterol by a single brand of allicin-standardized garlic powder tablets is in contrast to many prior positive studies with the same brand. The hypocholesterolemic activity of garlic is mainly due to allicin, a compound that is produced by the acid-sensitive garlic enzyme, alliinase, only after tablet consumption. Therefore, the allicin-releasing ability of ten lots of these tablets--manufactured over the same years that the positive and negative clinical trials were conducted (1989-1997)--was determined under simulated gastrointestinal dissolution conditions, as defined by U.S. Pharmacopeia Method 724A. It was found that the older lots were more resistant to acid-disintegration (2.5 h vs. 1.3 h, P < 0.001) and that they released three times as much allicin (44% vs. 15 % of their potential, P < 0.001) as the newer lots. A second brand of tablets employed in a recent negative trial released no detectable amount of allicin, while a third set of tablets with high allicin release was used in a trial that gave positive effects. Hence, the persons involved in the recent negative clinical trials probably received considerably less allicin than did those in the older positive studies, possibly accounting for much of the discrepancy in the outcomes. In conclusion, clinical trials using garlic powder tablets to assess any effect of garlic that might be related to allicin, as most are, cannot be considered valid for garlic when the trial shows no effect, unless the expected allicin release from the tablets has at least been determined under standardized drug release conditions (USP 724A).     

Tracking vaccine lot lifecycles using reports to the vaccine adverse event reporting system (VAERS)

PURPOSE: There is currently no systematically available information available on how rapidly a specific lot of vaccine is used once distributed. We used data from reports to the Vaccine Adverse Event Reporting System (VAERS) to develop a proxy means of surveillance for the lifecycle of selected vaccine lots. METHODS: A convenience sample, consisting of selected lots of: diphtheria, tetanus, and acellular pertussis (DTaP), Haemophilus influenzae type b (Hib), Hepatitis B, and varicella vaccines, was selected for lifecycle analysis. Assuming that circulation of a vaccine lot is proportional to vaccine-specific adverse event (AE) reporting for that vaccine type, we constructed Gamma distributed usage models and compared them with lot-specific VAERS reports to estimate the actual lifecycle of lots in the system. RESULTS: Evidence of lot circulation was detected within 1-2 months, and a peak was observed 3-4 months after the vaccine release date for most of the study vaccines. Ninety percent of the vaccine doses in each lot were estimated to be used within 5-9 months of distribution. The length of time a vaccine lot was in use ranged from 5 to 17 months from earliest vaccination date. CONCLUSIONS: Our modeled and inferred administration of the selected lots of different vaccines were concordant. This method may be useful for spatial and temporal tracking of vaccine lot utilization.     

Multivariate analysis of nuclear magnetic resonance data--characterization of critical drug substance quality of gentamicin sulfate

Fourteen gentamicin sulfate lots collected from international markets showed high quantities of impurities (30% of studied lots). ¹H NMR spectroscopy as a primary analytical method was applied in order to validate the quantification results obtained from micellar electrokinetic chromatography method (MEKC). In this study, ¹H NMR data of 46 gentamicin sulfate drug substance lots were used to classify the lots by means of principal component analysis (PCA) of 14 ¹H NMR-signals in the 5.0–6.0 ppm region. Three main groups could be classified: high purity (3 lots), average quality (28 lots) and low purity (14 lots); one lot proved to be atypical. The 14 normalized signal heights in the 5.0–6.0 ppm region are predictive for purity quality according to a partial least squares (PLS)-model with sum of all impurities as Y-variable (measured by MEKC).     

头孢氨苄、头孢拉定原料中残留2-萘酚的控制

目的:探讨对头孢氨苄、头孢拉定原料中增加2-萘酚检查的必要性,建立科学、合理的2-萘酚检查方法以及限度。方法:采用HPLC-UV法,C18(4.6 mm×250 mm,5μm)色谱柱,以甲醇-水(55∶45)为流动相,流速为1.0 mL.min-1;检测波长为225 nm,分析20批头孢氨苄原料、2批头孢拉定原料以及217批头孢氨苄片(胶囊)、380批头孢拉定胶囊中含2-萘酚的量,并进行方法学验证。结果:方法专属性强、线性范围宽、精密度好、准确度高、耐用性好,超过50%的样品含有不同量的2-萘酚,有些企业样品中含量较大,同一企业样品批间差异较大;根据当前ICH指导原则以及已发表的文献资料,初步确定了头孢氨苄、头孢拉定原料中2-萘酚的限度。结论:建议在中国药典头孢氨苄、头孢拉定原料中增加2-萘酚检查项并初步拟定了限度,其限度科学性、合理性需进一步验证。     

PYA与营养琼脂培养基细菌计数比较

目的：验证细菌计数培养基（PYA）在微生物限度检查中的实用价值.方法：按《中国药典》2000年版微生物限度检查法细菌计数的规定,比较PYA和营养琼脂培养基在细菌数检查中的差异.结果：通过对丸剂、片剂、颗粒剂和胶囊四种剂型168批样品PYA和营养琼脂细菌数检查结果表明,有7批样品（4.2%）PYA有细菌生长,而营养琼脂无细菌生长,未发现相反的现象;PYA细菌计数高于营养琼脂21%以上的样品数为32批,远多于营养琼脂高于PYA的21批;此外,PYA比营养琼脂细菌数平均增加了11.5%.结论：PYA在药品细菌教检查中优于营养琼脂,可替代营养琼脂用于药品微生物限度检查.