注射用头孢孟多酯钠在4种常用液体中的稳定性考察

目的考察注射用头孢孟多酯钠在25℃下与0．9％氯化钠注射液、5％葡萄糖注射液、10％葡萄糖注射液和5％葡萄糖氯化钠注射液4种常用输液液体配伍的稳定性。方法将注射用头孢孟多酯钠与输液配伍,采用高效液相色谱法测定头孢孟多酯钠的含量变化,并考察配伍液的外观和pH变化。结果注射用头孢孟多酯钠与0．9％氯化钠及5％葡萄糖氯化钠在室温下（25％）配伍,0～8h内其外观、pH值及含量无明显变化。而与5％葡萄糖注射液、10％葡萄糖注射液配伍稳定性欠佳。结论注射用头孢孟多酯钠与输液配伍时应选择0．9％氯化钠注射液或5％葡萄糖氯化钠注射液,不宜与5％葡萄糖注射液和10％葡萄糖注射液配伍。     

1H-NMR法分析头孢孟多酯钠对照品

目的　测定首批对照品头孢孟多酯钠含量和头孢孟多校正因子。方法　采用 L C/ MSNMR的方法鉴定了样品中所含的主要降解产物为头孢孟多 ;选择合适的溶剂防止降解反应的发生 ,采用 NMR法测定头孢孟多酯钠和头孢孟多的含量 ,计算出头孢孟多相对于头孢孟多酯钠的校正因子 ,同时采用 L C法对测定结果进行了验证。结果　NMR与 L C含量测定及校正因子测定结果一致。结论　NMR法测定含量方法准确、简便、快速 ,NMR测定校正因子方法可行     

Evaluation of stability of cefuroxime axetil in solid state

The effect of temperature and relative atmospheric humidity on the stability of the crystalline form of cefuroxime axetil (CFA) in solid state was investigated. CFA is a mixture of diastereomers A and B. Changes in the concentration of the two diastereomers (A and B) of CFA were recorded by means of HPLC with UV detection. The degradation of diastereomers of CFA occurring at 0% relative humidity (RH) of the ambient air is a reversible first order reaction, while that occurring in humid air (RH>50%) is an autocatalytic first order reaction relative to substrate concentration. Although it has been found, that diastereomer B is the more stable isomer, humidity has a stronger effect on this very diastereomer.     

注射用头孢孟多酯钠与注射用奥美拉唑钠序贯静滴的稳定性研究

目的：研究注射用头孢孟多酯钠与注射用奥美拉唑钠序贯静滴的配伍稳定性。方法：参考临床常用质量浓度,配制头孢孟多酯钠与5%葡萄糖注射液配伍溶液,再取该配伍溶液分别与不同体积的奥美拉唑钠溶液配伍。于0,0.5,1,2,3,4,5,6 h观察各配伍液的外观性状变化,测定pH值和不溶性微粒数,并采用HPLC法测定各配伍液头孢孟多酯钠的相对百分含量。结果：头孢孟多酯钠与5%葡萄糖注射液的配伍液在6 h 内外观无明显变化,与不同体积奥美拉唑钠配伍的配伍液随时间延长出现不同颜色的浑浊,在6 h内各配伍液中不溶性微粒数均符合规定,头孢孟多酯钠的相对百分含量略有下降。结论：在临床上,若注射用头孢孟多酯钠与注射用奥美拉唑钠静滴联用时,最好在两者之间先用0.9%氯化钠注射液清洗输液管道,完毕后再输注另一种药物,或者不将两者连续使用。     

HPLC-DAD考察头孢孟多酯钠与卡络磺钠在5%葡萄糖注射液和0.9%氯化钠注射液中的配伍稳定性

目的考察室温(25℃)下,注射用头孢孟多酯钠与注射用卡络磺钠分别在5%葡萄糖注射液和0.9%氯化钠注射液中的配伍稳定性。方法采用反相高效液相色谱法-二极管阵列检测器分别测定0～6 h内配伍液中头孢孟多酯钠和卡络磺钠的含量变化,同时观察配伍溶液的外观和测定其pH值。结果在室温(25℃)下、6 h内,配伍液外观无明显变化,但pH值和含量均变化明显。结论在室温(25℃)下、6 h内,注射用头孢孟多酯钠与注射用卡络磺钠在5%葡萄糖注射液和0.9%氯化钠注射液中配伍均不稳定。     

The use of mixed-mode ion-exchange solid phase extraction to characterize pharmaceutical drug degradation

Solid phase extraction (SPE) has been utilized extensively in the pharmaceutical industry for the isolation of pharmaceuticals from interfering biological matrices and the purification and concentration of impurities and degradation products present in analytical samples. The work described herein involves the novel use of mixed-mode ion-exchange solid phase extraction to characterize degradation products of several pharmaceutical drugs, thereby giving important clues to their structure and sites of reactivity. Several examples of the use of mixed-mode ion-exchange solid phase extraction to illustrate the utility of this technique are presented.     

几种固相萃取新技术近十年的研究进展（英文）

固相萃取技术是近年来发展较快并得到广泛应用的一种样品前处理方法 （分离、纯化、富集）, 具有节省时间、溶剂消耗少, 富集倍数高, 准确度高等优点。随着科学技术的不断发展及研究的不断深入, 多种优于传统固相萃取技术的新型固相萃取新技术如分子印迹固相萃取、磁性固相萃取、固相微萃取等不断出现并广泛应用到食品、药品、生物及环境监测等领域。本文对几种固相萃取新技术的基本原理、方法及近十年来在不同研究领域的研究应用进行综述。     

固体口服制剂的相转化研究进展

固体口服制剂的相转化研究对选择工艺流程和研发新产品有重要意义。根据相转化机制，固相相变可以分为3种类型：多晶型的转化（polymorphic transition），水化与脱水（hydration／dehydration），玻璃化相与结晶（vierfication/crystallization）的相互转化。固体口服新制剂研究中应重视药物多晶型和无定形现象，预防和防治固相处方设计与工艺流程选择中发送的相转化。     

Conductance measurements in solid phase peptide synthesis

Potentiated conductance shows promise for monitoring the progress of both coupling and deprotection reactions in solid phase peptide synthesis using Fmoc chemistry. Sterically hindered base may be added to the aprotic polar solvents used for synthesis, this induces ionisation of acids formed in the coupling and deprotection reactions, thus giving rise to a conductance signal in the solvent. Changes in this signal allow reactions occurring at the resin to be followed with no degradation of coupling efficiency.     

A comparison of the stability of ertapenem and meropenem in pharmaceutical preparations in solid state

The following first-order rate constants of the degradation of ertapenem in INVANZ and meropenem in MERONEM were determined: (a) in dry air at 363, 373, 378, 383, 388, 393 K; (b) at increased relative air humidity (76.4% RH) at 313, 323, 333 and 343 K; (c) at increased relative air humidity (50.9, 60.5, 66.5, 76.4% RH-ertapenem and 50.9, 66.5, 76.4 and 90.0% RH-meropenem) at 333 K. The dependence ln k(i) = f(RH%) was described by the equations: ln k(i) = (6.63+/-1.22) x 10(-2) x (RH%)-13.36 +/- 1.68 (ertapenem) and ln k(i) = (4.22 +/- 2.98) x 10(-2) x (RH%)-12.14 +/- 2.16 (meropenem). The dependence lnk(i)=f(1/T) was described by equations: ln k(i) =19.4 +/- 2.6-(9230 +/- 800)(1/T) for ertapenem, at 76.4% RH; ln k(i) = 11.5 +/- 4.9-(9880 +/- 1800)(1/T) for ertapenem in dry air; ln k(i) = 14.8 +/- 11.9-(7785 +/- 3905)(1/T) for meropenem, at 76.4% RH; ln k(i) = 37.6 +/- 7.73-(18385 +/- 2930)(1/T) for meropenem in dry air. The thermodynamic parameters E(a), DeltaH( not equal) and DeltaS( not equal) of the degradation of ertapenem and meropenem were calculated. The difference between the influence of temperature on the stability of ertapenem and meropenem was not significant at 76.4% RH. In dry air (363-393 K) this influence was greater in the case of meropenem. The degradation of ertapenem was slower in this temperature range. Humidity was a significant factor affecting the degradation of these antibiotics and it influenced their stability is similar ways.     

固相萃取在生物样品分析中的应用

生物样品中的药物浓度与药物的疗效有很大的相关性,尤其是血浆(或血清)药物浓度直接与药效相关。尿液中常常含有丰富的药物代谢产物,也被经常使用。唾液由于采集方便且有时和血浆游离药物浓度具有相关性而有时使用。其他脏器组织,除特别需要,较少用。生物样品的药物分析因其复杂多样性而对样品的预处理技术提出了较高的要求。在各种处理方法中,固相萃取由于其适用性广,实用性强而越来越受到广大科研工作者的重视。本文综述了固相萃取技术(SPE)及其在生物样品分析中应用的相关报道,以期对相关研究者提供理论指导和技术支持。     

Acid-labile resin linkage agents for use in solid phase peptide synthesis

Details are given of the preparation of two acid-labile peptide-resin linkage agents for use in solid phase peptide synthesis, viz. 4-hydroxymethylphenoxy-acetic acid and 3-methoxy-4-hydroxymethylphenoxyacetic acid. The latter is suitable for the preparation of peptide fragments bearing t-butyl-based side chain protecting groups.     

High-performance liquid chromatographic determination of doxorubicin in tissues after solid phase extraction

A method is described for the determination of doxorubicin in tissues. The drug was selectively extracted from the biological matrix by solid phase extraction using 1-ml octadecyl silane extraction columns. Prior to extraction, tissue samples were digested by an enzymic digestion procedure. Daunorubicin was used as an internal standard. Quantitation was by high-performance liquid chromatography (HPLC) using ion-pair chromatography on a reversed-phase column. Detection was by fluorescence.

Recovery of doxorubicin from tissue was 81.7 ± 2.1% mean ±SD. Doxorubicin concentrations as low as 0.01 mg kg⁻¹ could be determined. A typical value of the relative standard error of measurement was 3.7% at 2.1 mg kg⁻¹.     

The influence of pH, temperature and buffers on the degradation kinetics of cefetamet pivoxil hydrochloride in aqueous solutions

The first-order hydrolysis kinetics of cefetamet pivoxil (CP) were investigated as a function of pH, temperature and buffers. The degradation was followed by HPLC. Buffer catalysis was observed in acetate and phosphate buffers. The pH–rate profiles for hydrolysis of cefetamet pivoxil were obtained at 333, 343, 353 and 363 K. The pH–rate expression was k_pH=k_H⁺a_H⁺+k_H2Ok_OH⁻a_OH⁻, where k_H⁺ and k_OH⁻ are the second-order rate constants (mol⁻¹ l s⁻¹) for hydrogen ion activity and for hydroxyl ion activity respectively, and k_H2O is the pseudo-first-order rate constant (s⁻¹) for spontaneous reaction under the influence of water. The pH–rate profile was characteristically U-shaped. Maximum stability was observed in the pH region from 3 to 5.     

A phase I trial of fazarabine in refractory pediatric solid tumors

Summary Fazarabine is a synthetic analog of cytosine arabinoside and 5-azacytidine that incorporates structural features of both compounds. Xenograft studies showed good activity against a variety of transplanted tumors. Initial studies in adults employed both a continuous infusion schedule and a daily bolus x 5 schedule. Myelotoxicity, especially neutropenia, was dose-limiting, with excessive myelotoxicity seen on the daily bolus x 5 at 72 mg/M²/day. Since short infusions may be administered in Ringer's lactate rather than either dimethylsulfoxide or dimethylacetamide required for continuous infusion, this study examined a daily x 5 schedule in children with refractory solid tumors. The initial dosage was 30 mg/M²/day, 80% of the maximum tolerated dosage in adults, with subsequent 30% dosage escalations. A total of 18 patients were enrolled, with a wide spectrum of pediatric solid tumors. Myelosuppression was the only significant toxicity, and was excessive at 78 mg/M²/day. Therefore, on this bolus regimen, 65 mg/M²/day for 5 days was the maximum tolerated dosage. One patient with medulloblastoma had stable disease for 65 days. No other responses were seen.     

核磁共振光谱法在固相合成中的应用及进展

目的介绍近年来NMR技术在固相合成中的应用情况及进展。方法根据常见的用于测定核磁共振信号的原子核的不同 ,对核磁共振光谱进行分类叙述。结果与结论对于固相合成 ,传统的分析方法不适合分析与树脂相连的化合物 ,严重限制了固相合成的进一步发展。随着魔角自旋技术等一系列新技术的发展和应用 ,NMR光谱法不仅可以基本满足固相合成的需要 ,还能在一定程度上促进它的发展。     

Kinetics of degradation of cefetamet pivaloyloxymethyl ester and its hydrochloride in solid phase

The influence of temperature and relative humidity on the stability of cefetamet pivoxil (CFP) and its hydrochloride (CFP.HCl) in solid phase was investigated. The process of degradation was studied using HPLC with UV detection. The degradation of CFP and CFP.HCl occurring at air humidity RH>50% is an autocatalytic first-order reaction with respect to substrate concentration, while at 0% relative humidity of the ambient air it is a first-order reaction relative to substrate concentration for CFP.HCl, and a reversible first-order reaction for CFP. The rate constants (k) were determined in dry air at 373 K, 378 K, 383 K, 388 K and 393 K; at air humidity RH = 76.4% at 333 K, .343 K, 353 K, 363 K and 373 K; and at 363 K at air humidity RH>50%. The kinetic and thermodynamic parameters of the degradation were calculated.     

Peptide N-alkylamides by solid phase synthesis*

Three new resins have been developed that allow for the solid phase synthesis of C-terminal peptide N-alkylamides using Boc amino acids, usual side chain protecting groups and hydrogen fluoride cleavage and deprotection. These resins were prepared by reacting the appropriate alkylamine (NH₂ CH₃, NH₂ CH₂ CH₃, NH₂ CH₂ CF₃) to Merrifield's 1% divinylbenzene cross-linked chloromethylated polystyrene resin. The application of these resins to the synthesis of C-terminal GnRH N-alkylamides illustrates the versatility of this approach. GnRH analogs were tested for their ability to release LH from cultured rat anterior pituitary cells. [D Glu⁶, Pro⁹-NHCH₂ CH₃]-GnRH was synthesized for the first time using the solid phase approach and found to be three times more potent than [D Glu⁶]-GnRH. Other analogs including [D Trp⁶, Pro⁹-NHCH₂ CH₃]-GnRH, [D Ala⁶, Pro⁹-NHCH₂ CF₃]-GnRH and related peptides were found to be equipotent and to have the same properties (HPLC retention times, amino acid analysis and specific rotation) as the corresponding peptides synthesized using less amenable strategies; yields were equivalent or better than those reported earlier.     

固相萃取-高效液相色谱法测定人血清中头孢吡肟浓度

目的:建立高效液相色谱法检测人血清中头孢吡肟浓度。方法:血清经固相萃取后,在WatersSymmetryshieldRP18色谱柱上,以甲醇-20mmol·L-1醋酸铵溶液(13∶87)为流动相,流速1.0mL·min-1,波长检测254nm。结果:头孢吡肟的保留时间为6.82min,最低定量限为0.5mg·L-1,线性范围0.5~100.0mg·L-1,萃取回收率82.95%~86.25%,方法回收率98.05%~101.03%,日内RSD4.29%~9.83%,日间RSD5.21%~10.57%。结论:该法准确可靠,可用于头孢吡肟的临床药动学研究及临床特殊人群的血药浓度测定。     

固相萃取-高效液相色谱法测定人血清中莫西沙星浓度

目的：建立高效液相色谱法检测人血清中莫西沙星浓度。方法：血清经固相萃取后，在Waters Symmetry shield RP18色谱柱上，以乙腈-10mmol·L^-1磷酸二氢钾溶液（19：81）为流动相，流速1．0mL·min^-1，296nm波长检测。结果：莫西沙星的保留时间：08．82min，最低定量限为0．05mg·L^-1，最低检测限0．015mg·L^-1，线性范围0．05～5．00mg·L^-1，萃取回收率91．05％～98．40％，方法回收率96．05％～101．05％，日内RSD2．88％～4．44％，日间RSD5．22％～9．53％。结论：该法准确可靠，可用于莫西沙星的临床药动学研究及临床特殊人群的血药浓度测定。