高效液相色谱法测定药用辅料苯甲醇中苯甲酸和苯甲醛含量

目的建立HPLC法同时测定药用辅料苯甲醇中苯甲酸和苯甲醛的含量。方法采用Acclaim 120 C18柱(4.6 mm×250 mm,5μm),流动相为乙腈-0.02%甲酸(用氨水调至p H=4.5)(30:70),流速为1.0 m L·min-1,检测波长为230 nm,柱温为35℃,进样量为20μL。结果苯甲酸在0.500 6¹5.02μg·m L-1内与峰面积线性关系良好,平均回收率均>100%,RSD均<1.3%(n=3);苯甲醛在0.505 215.02μg·m L-1内与峰面积线性关系良好,平均回收率均>100%,RSD均<1.3%(n=3);苯甲醛在0.505 2¹5.16μg·m L-1内与峰面积的线性关系良好,平均回收率均>108%,RSD均<0.15%(n=3)。结论本方法准确度高、重现性好,可用于苯甲醇中苯甲酸和苯甲醛的含量测定。     

GC法测定恩替卡韦中的苯甲醇和氯化苄

目的 采用GC法测定恩替卡韦中的苯甲醇和氯化苄.方法 采用毛细管GC法,色谱柱为HP-5(30 m×0.32 mm,0.25 μm),载气为氮气,流速1.0 mL·min-1,柱温115℃,保持6 min,检测器温度300℃,样口温度260℃,分流比3∶1,手动进样,以外标法计算含量.结果 26.72～106.9 μg...     

Time-dependent conversion of benzyl alcohol to benzaldehyde and benzoic acid in aqueous solutions

The oxidative reaction: benzyl alcohol-benzaldehyde-benzoic acid was investigated in time in aqueous solutions of benzyl alcohol widely used as a preservative in medicine and cosmetology. The solutions of benzyl alcohol were stored at concentrations from 0.005 to 2.09 mg/ml for a long time under different conditions. The presence of benzaldehyde and benzoic acid in these solutions was controlled by liquid chromatography on silica sorbent in water. The content of benzoic acid and potentially toxic benzaldehyde in solutions depending on the initial concentration of benzyl alcohol, on time, and on storage conditions was evaluated quantitatively.     

Sorption of parabens by fluoropolymer or fluoropolymer laminated flexible tubing.

Earlier studies using methylparaben and propylparaben showed extensive losses due to sorption by silicone, polyvinyl chloride, and other flexible tubing. As much as 100% loss of propylparaben and significant loss of methylparaben was reported within 24 hours using Tygon, Clearflo, or Silastic tubing. The fluoropolymer Teflon FEP did not show sorption losses. The current study was conducted using three different fluoropolymer resin tubing pieces (FEP, PFA, and NXT or PTFE) as well as a Tygon tubing lined with FEP to show that these do not show paraben sorption losses over an extended period of time. The results of this study show that sorption losses can be avoided or reduced by proper selection of flexible tubing.     

Simultaneous analysis of dehydroacetic acid, benzoic acid, sorbic acid and salicylic acid in cosmetic products by solid-phase extraction and high-performance liquid chromatography

A high-performance liquid chromatographic (HPLC) method for simultaneous determination of dehydroacetic acid (DHA), benzoic acid (BA), sorbic acid (SOA) and salicylic acid (SA) was developed for application to cosmetic products. Isocratic reversed-phase HPLC was employed for quantitative analysis using tetra-n-butylammonium (TBA) hydroxide as an ion-pair reagent. Cosmetic samples were purified by solid-phase extraction using Bond-Elut SI cartridges. Four acidic preservatives were eluted with methanol from cartridges. The HPLC assay was carried out using TSK gel ODS-80TM column (5 microm, 150 x 4.6 mm I.D.). The mobile phase consisted of a mixture of water and methanol (65:35, v/v) containing 2.5 mM TBA hydroxide adjusted with phosphoric acid to pH 7.0. The calibration curves of these preservatives showed good linearity with UV detection (235 nm). The correlation coefficients were better than 0.999 in all cases. The lower limits of detection (defined as a signal-to-noise ratio of about 3) were approximately 2.5 ng for DHA, 4.0 ng for BA, 2.0 ng for SOA and 5.5 ng for SA. The procedure described here is simple, selective and is suitable for quality control of finished cosmetic products.     

Determination of benzalkonium chloride by gas chromatography

A new, simple, and useful approach for the analysis of benzalkonium chloride is presented. A gas chromatography (GC) has been used to pyrolyze benzalkonium chloride in a specific and reproducible manner to yield two tertiary amines for each homologue of benzalkonium chloride present. These are separated by GC and are used to determine the homologue composition of the benzalkonium chloride. These determinations can be made with an analysis time of 25 min/sample.     

离子色谱法测定不同工艺级别的苯甲醇中氯化物的含量

目的建立离子色谱法测定苯甲醇中氯化物的含量,并评价不同工艺级别苯甲醇中氯化物含量的质量状况。方法色谱柱为Rfi c Ion Pac AG11-HC保护柱(50 mm×4 mm),Rfi c Ion Pac AS19分析柱(250 mm×4 mm),淋洗液为10 mmol·L-1 KOH溶液,抑制电流为120 m A,进样量为25μL,流速为1.0m L·min-1,采集时间为12 min,柱温为20℃。结果 Cl-在1.494 5~29.89μg·m L-1内线性关系良好,回收率在95.1%~96.7%。结论本法快速、准确、可靠,可用于苯甲醇中氯化物的测定。相对化工级别和原料级别而言,药用辅料级别样品中Cl-略微偏高,但仍控制在很低的水平。     

气相色谱法测定苯甲醇的含量

目的建立气相色谱法测定苯甲醇的含量。方法采用Rtx-Wax气相毛细管柱(0.25 mm×30 m,0.25μm),FID检测器,柱温130℃;进样口温度为200℃;检测器温度230℃。结果苯甲醇在0.543 3¹.629 8mg·mL-1内与峰面积呈良好线性关系(r=0.999 5),低、中、高浓度的平均回收率在100.0%1.629 8mg·mL-1内与峰面积呈良好线性关系(r=0.999 5),低、中、高浓度的平均回收率在100.0%¹01.4%,RSD均<2.2%(n=3)。结论本方法准确度高、重现性好,适用于苯甲醇的含量测定。     

Sorption of parabens by flexible tubings

Flexible tubings are extensively used in pharmaceuticals, food industry, and in hospitals. This study was undertaken to compare various flexible tubings to determine their sorption characteristics, using methyl and propyl parabens. After 24 h, some tubings showed 100% sorption of propylparaben and over 40% for methylparaben. Significant losses were observed within a few hours using several tubings. For methylparaben, the losses were in the following decreasing order of sorption: Tygon, Clearflo, silicone, Nylotube, and Newtex. For propylparaben, the losses were in the following order: Tygon, Clearflo, silicone, Newtex, and Nylotube. Teflon, Zelite, and Vitube showed little to no losses of methyl and propylparaben over 120 h of study. The silicone tubing, refilled after 120 h with fresh methylparaben or propylparaben solutions, again showed significant losses within a few hours. The tubings show slow desorption when filled with the buffer vehicle. For Silastic tubing, increase in temperature from 25 to 40 degrees C, increase in pH from 3.5 to 6.5, tubing lot to lot variation, or curing with peroxide or platinum had little or no effect on paraben sorption. As expected, the sorption of parabens increased with increasing surface area of Silastic tubing. Results provided can be used to select the best tubings and to minimize paraben losses during production and filling of liquid pharmaceuticals andfood products containing these antimicrobial preservatives.     

高效液相色谱法测定复方苯甲酸软膏中苯甲酸和水杨酸的含量

目的建立测定复方苯甲酸软膏中苯甲酸和水杨酸含量的高效液相色谱法.方法固定相采用μBondapak C18柱,流动相为:甲醇-0.02mol·L-1KH2PO4溶液(磷酸调pH=3.1)(60:40),检测波长为270nm.结果水杨酸和苯甲酸的线性范围分别5～25μg·mL-1(r=0.9995)、10～50μg·mL-1(r=0.9998);平均加样回收率分别为99.3%,100.6%;日内RSD分别为0.64%,0.58%;日间RSD分别为0.65%,0.66%(n=5).结论本法适用于复方苯甲酸软膏的质量控制,方法简便、灵敏,结果准确.     

高效液相色谱法同时测定复方苯甲酸软膏中的苯甲酸和水杨酸含量

目的：建立一种快速、准确的高效液相色谱法同时测定苯甲酸和水杨酸的含量，方法：使用阴离子交换色谱柱，流动相为甲醇－0．05mol.L^-1磷酸二氢钾（30：70），检测波长为244nm，结果：样品测定在8min内完成，苯甲酸在60－480mgL^-1范围内，r=0.9995,RSD=0.72%，平均回收率为99．5％，水杨酸在30－240mg.l^-1范围内，r=0.9995,RSD=0.67%,平均回收率为100．7％，结论：本方法可快速准确地检测复方苯甲酸软膏中的苯甲酸和水杨酸含量。     

紫外分光光度法测定复方苯甲酸涂剂中苯甲酸和水杨酸的含量

目的：建立复方苯甲酸制剂中苯甲酸和水杨酸含量的检测方法,方法：采用紫外分光光度法,直接测定两组分的含量,结果：可同时测出苯甲酸和水杨酸的各自含量,且吸收度与各自浓度良好性线性关系,苯甲酸平均回收率为１００．２％,ＲＳＤ为０．２０％,水杨酸平均回收率为１００．４％,ＲＳＤ为０．３２％,结论;本方法简便,快速,可靠,可用于复方苯酸制剂中苯甲酸和水杨酸的含量测定。     

Effect of chitosan, benzalkonium chloride and ethylenediaminetetraacetic acid on permeation of acyclovir across isolated rabbit cornea

The overall objective of this study was to evaluate the effect of chitosan, benzalkonium chloride (BAK) and disodium ethylendiaminetetraacetic acid (EDTA), alone and in combination, on permeation of acyclovir (ACV) across excised rabbit cornea. Corneas of male New Zealand White rabbits were used in these studies. Transcorneal permeation studies were conducted at 34 degrees C using a side-bi-side diffusion apparatus. In the presence of 0.01% BAK, transcorneal permeability of ACV was observed to increase almost 10.5-fold, from 3.5x10(-6) to 37.4x10(-6)cm/s. At 0.005% BAK, permeability of ACV was almost 3-fold higher than control. Combination of BAK 0.005% and EDTA 0.01% increased transcorneal penetration of ACV by 2.5-fold. Chitosan 0.2 and 0.1% increased corneal permeability of ACV by 5.8- and 3.1-fold, respectively, whereas, at 0.02%, chitosan did not exhibit a statistically significant effect. BAK at 0.005%, in combination with 0.01% EDTA and 0.1% chitosan, increased transcorneal ACV permeation by 5.5-fold. This study suggests that a judicious combination of chitosan, BAK and EDTA can lead to a significant increase in ACV's transcorneal permeability and that chitosan can enhance diffusion of hydrophilic agents across the corneal membrane. Further in vivo evaluation is warranted.     

In vitro genotoxicity and cytotoxicity of benzalkonium chloride

Benzalkonium chloride (BAC) acts as a preservative in numerous nasal preparations. Possible genotoxic and cytotoxic effects of BAC in human respiratory epithelial BEAS-2B cells should be investigated in vitro.

Cell cultures were exposed for 2 h to BAC in concentrations ranging from 0.002% to 0.05%. Methyl methanesulfonate served as positive control, PBS as negative control. The tail moment of single-cell gel-electrophoresis (SCGE) was used to assess BAC-induced DNA damage. Cell viability was measured by trypan blue dye exclusion staining. Additionally, the critical micellar concentration (CMC) of BAC in PBS was detected.

The tail moment increased dose dependently with the maximum value at 0.02%, and declined for higher concentrations. Nearly all cells died at low BAC concentrations up to 0.01%. Above this concentration cell viability increased. The CMC of BAC in PBS was estimated to be 0.02%.

BAC caused relevant DNA changes in respiratory epithelial cells in vitro at concentrations commonly employed in commercially available nasal preparations. Some of the exposed cells survived. In further studies it could be considered to look whether these cells would still be able to proliferate and possibly fix the damage that they have possibly accumulated into an actual mutation using for example the induction of micronuclei.     

The determination of benzalkonium chloride in eye-drops by difference spectrophotometry

A direct, extraction-free spectrophotometric method was developed for the determination of benzalkonium chloride (BAC) in various eye-drops. The procedure is based on ion-pair formation between BAC and 2′,4′,5′,7′-tetrabromofluorescein (eosin-Y) which decreases the absorbance and induces a bathochromic shift of the maximum in the eosin-Y spectrum. The effects of pH, excess of reagent and ionic strength on the ion-pair formation have been studied in detail. At pH 4.40 and 9.62, the working curve is linear in the 1.98×10⁻⁶ to 2.40×10⁻⁵ M (0.7–8.5 μg cm⁻³) concentration range; however, the sensitivity drops to about one third in the basic solution. At pH 4.40, the analytical signal is stable for more than 60 min, while at pH 9.62 the signal changes in time and reaches the maximum value 3 min after mixing the reagent and the sample. When the active substance is β-5-isopropyl-2′deoxyuridine and the sample contains typical additives, the reproducibility of the analytical signal at pH 4.40 is R.S.D.=2.36% (n=81). In the case of such samples, the linearity of the method is somewhat dependent on the composition, but generally acceptable at the 50–150% concentration levels. Eye-drops containing tobramycin, an aminoglycoside-type antibiotic, as the active substance were analyzed at pH 9.62. This was necessary to avoid strong interference from the analyte in acidic solution. In this case the linearity of the method is limited to a narrower concentration range; however, the recovery is still acceptable at the 100% level.     

RP-HPLC法同时测定浓苯甲酸水杨酸软膏中苯甲酸和水杨酸的含量

目的建立同时测定新型浓苯甲酸水杨酸软膏中苯甲酸和水杨酸浓度的RP-HPLC法。方法采用Kromasil-C₁₈（150 mm×4.6 mm,5μm）色谱柱;流动相为V（甲醇）:V(0.02 mol·L^-1,KH₂PO₄溶液,磷酸调pH=3.1)=50:50;检测波长280nm;流速1.0 mL·min^-1;柱温20℃。结果苯甲酸、水杨酸进样质量浓度分别为96～144 mg·L^-1（r=0.999 5）、48～72 mg·L^-1（r=0.999 7）时具良好线性关系,加样回收率分别为99.6%～100.6%、99.4%～100.2%,批间、批内RSD为0.3%～0.7%。结论本方法简便、精确、重现性好,适用于测定新型浓苯甲酸水杨酸软膏中苯甲酸和水杨酸浓度。     

HPLC法同时测定阿奇霉素滴眼液中阿奇霉素及苯扎氯铵的含量

目的建立一种高效液相色谱法同时测定阿奇霉素滴眼液中阿奇霉素及苯扎氯铵的含量。方法采用十八烷基硅烷键合硅胶色谱柱(4.6 mm×150 mm,5μm),柱温30℃,以乙腈-磷酸盐缓冲液(取0.05 mol.L-1磷酸氢二钾溶液,用20%磷酸调节pH至8.2)(58∶42)为流动相;检测波长210 nm;流速:1.0 mL.min-1。结果阿奇霉素在1.002 8～5.014 0 mg.mL-1的浓度范围内,苯扎氯铵在6.15μg.mL-1～14.35μg.mL-1的浓度范围内均呈线性。阿奇霉素的平均回收率100.68%,RSD为0.50%(n=9);苯扎氯铵的平均回收率100.59%,RSD为0.92%(n=9)。阿奇霉素与苯扎氯铵的定量限分别为750 ng.mL-1、46 ng.mL-1,平均含量分别为106.94%及100.04%,RSD分别为0.94%及0.67%。仪器重复性RSD值均在2.0%以下。结论本方法简单、准确,可同时测定样品中阿奇霉素及苯扎氯铵的含量。     

Investigation of the adjuvant and immuno-suppressive effects of benzyl butyl phthalate, phthalic acid and benzyl alcohol in a murine injection model.

In a recent study, di-(2-ethylhexyl) phthalate (DEHP) and its metabolite, mono-2-ethylhexyl phthalate, were shown to possess adjuvant effect [Toxicology 169 (2001) 37; Toxicology Letters 125 (2001) 11]. The present study investigates the adjuvant effect of another important commercial phthalate plasticizer, benzyl butyl phthalate (BBP) as well as its degradation products, phthalic acid and benzyl alcohol (BA) in a murine model. The model antigen, ovalbumin (OA), was injected either alone (OA control group), together with one of the test substances (test group) or together with aluminium hydroxide, which served as the positive adjuvant control. The mice were boosted either once or twice with OA before blood was collected and assayed for the content of OA-specific IgE, IgG1 and IgG2a antibodies by ELISA methods. Adjuvant effect was defined as a statistically significant increased antibody level in the test groups compared with the OA control group. Conversely, if the antibody production in a test group was significantly lower than the OA control group, it was deemed to be immunosuppression. This study demonstrated that BBP, in contrast to DEHP, did not possess adjuvant effect. Furthermore, immunosuppression was apparent in the case of BA. The study also demonstrated that if the injections give rise to formation of wounds, it may cause false positive results.