The light sensitivity of corticosteroids in crystalline form. Photochemical studies. 59. (1)]

The light sensitivity of corticosteroids in the solid state have been investigated and the photodecomposition rates of the compounds have been estimated by HPLC. After 48 h UV-irradiation desoxycortone acetate, hydrocortisone, hydrocortisone acetate, prednisolone, methylprednisolone, dexamethasone, betamethasone and triamcinolone acetonide decompose between 20 and 50%. Cortisone acetate, prednisone and fluocinolone acetonide show photostability in contrast to requirements of the Pharmacopeia for light protections.     

Simultaneous determination of glucocorticoid alcohols, their succinates and hydrocortisone in plasma

A reversed-phase high-performance liquid chromatographic (HPLC) assay is described for the simultaneous determination of methylprednisolone, methylprednisolone-21-hemisuccinate and endogenous hydrocortisone in biological fluids. This assay is also applicable to the determination of prednisolone-21-hemisuccinate in the presence of prednisolone and hydrocortisone in biological fluids. Prednisolone and hydrocortisone are determined by normal-phase HPLC. The stability of hemisuccinate esters in ampoules, in saline and in plasma has been studied. Whereas the esters were stable in saline at 37°C, they were considerably hydrolysed in plasma at the same temperature. Comparison of hydrocortisone levels obtained by HPLC and radioimmunoassay (RIA) showed the large influence of the cross-reactivity of methylprednisolone and hydrocortisone in the presence of high serum concentrations of methylprednisolone.     

不同密度滚轮微针对曲安奈德的透皮促渗作用

目的探讨不同密度滚轮微针对曲安奈德经皮渗透的影响。方法采用改良Franz扩散池法考察体外经皮渗透特性,以离体裸鼠皮肤为屏障,对照组、192针、540针滚轮微针处理组分别于2、4、6、8、10、12h取接收液0．2ml,用HPLC法测定曲安奈德含量,计算累积渗透量,并测定皮肤内曲安奈德滞留量。采用测定血药浓度法考察在体吸收特性,在体给药2h后HPLC法测定各组皮肤及血浆中曲安奈德的含量。结果两种密度滚轮微针对曲安奈德均有不同程度的促透作用。离体透皮实验结果显示,192针微针处理组和540针微针处理组的累积渗透量Q分别是对照组的1．3倍和2．2倍,相应的皮肤内滞留量也分别是对照组的1．9倍和2．8倍。在体实验结果显示,192针微针和540针微针组的皮肤滞留量是对照组的2．1和2．3倍,同时也将血药浓度提高了1．3倍和1．4倍。结论结论两种不同密度滚轮微针均能有效提高曲安奈德的经皮渗透量,提高皮肤内药物含量,同时也导致血药浓度的增加,且不同密度微针的促透作用有所不同。     

曲安奈德离子导入在兔眼房水中的药代动力学研究初探

目的研究曲安奈德(TA)离子导入在兔眼房水中的药代动力学特点,为临床用药提供实验依据。方法以成年新西兰兔为实验动物,TA离子导入兔眼,不同时间点抽取兔眼房水,采用高效液相色谱(HPLC)法测定样本中的药物浓度,用DAS1.0拟合计算药代动力学参数。结果线性范围为0.025～2.000μg/ml,药代动力学参数:t1/2为(2.6±0.4)h,AUC(0~24h)为(1.37±0.16)mg.L-1.h-1,AUC(0-∞)为(1.37±0.21)mg.L-1.h,Cmax为(0.66±0.15)mg/L,Tmax为(0.50±0.17)h。结论建立的房水中TAHPLC测定方法简便、准确、稳定、可靠,适用于TA的药代动力学研究,TA经离子导入吸收快,在房水中药物浓度较高,离子导入比眼球内注射安全性高,为临床改变给药途径提供药代动力学参数。     

Association of ranibizumab (Lucentis®) or bevacizumab (Avastin®) with dexamethasone and triamcinolone acetonide: An in vitro stability assessment

The in vitro stability of monoclonal antibodies used for age-related macular degeneration, ranibizumab and bevacizumab, was investigated. The aggregation profile of the antibodies was compared, alone and after association with dexamethasone sodium phosphate or triamcinolone acetonide. Commercial formulations of ranibizumab and bevacizumab were dialysed into three different buffers. After dialysis, samples were stored at 4 °C, 25 °C and 40 °C during 35 days, alone and in combination with dexamethasone sodium phosphate, triamcinolone acetonide phosphate solution or triamcinolone acetonide suspension. Combined formulations based on both commercial formulations were investigated as well. The aggregation state of the antibodies was measured by multi-angle light scattering (MALS) after separation by asymmetrical flow field-flow fractionation (AFFF) or size-exclusion chromatography (SEC). Ranibizumab results to be more stable than bevacizumab, alone and in combination with dexamethasone sodium phosphate or triamcinolone acetonide. Elevation in concentration, pH and temperature causes a decrease in stability of both antibodies. The association of triamcinolone acetonide phosphate solution with either ranibizumab or bevacizumab is observed to be the least stable combination of all samples tested. Dexamethasone sodium phosphate was shown to have a stabilizing effect on bevacizumab, although this is not the case for its combination with the commercial formulation Avastin®. The results demonstrate that the in vitro association of either ranibizumab or bevacizumab with dexamethasone sodium phosphate or triamcinolone acetonide suspension does not decrease the stability of these antibodies. Although ranibizumab is more stable than bevacizumab in vitro, further research has to point out how this affects their mechanism of action in vivo.     

High-performance liquid chromatography-diode array and electrospray-mass spectrometry analysis of non-allowed substances in cosmetic products for preventing hair loss and other hormone-dependent skin diseases

A simple high-performance liquid chromatography (HPLC) method with ultraviolet diode array (UV-DAD) and electrospray ionisation mass spectrometry (ESI-MS) detection has been developed for the determination of minoxidil, progesterone, estrone, spironolactone, canrenone, hydrocortisone and triamcinolone acetonide in cosmetic products. The presence of these substances in commercial cosmetic samples is prohibited. The compounds were separated by reversed phase chromatography with water (0.1% trifluoroacetic acid) and acetonitrile gradient elution and detected by UV-DAD at 230, 254 and 280 nm and by ESI-MS positive ionisation mode. Benzoic acid was used as internal standard. Linearity was studied with UV-DAD detection from 1.50 to 1,000 microg/ml or mug/g range, depending on the different compounds and type of cosmetic preparation and with ESI-MS in the 50-1,000 ng/ml or ng/g range. Good determination coefficients (r(2)>or=0.99) were found in both UV and ESI-MS. At three concentrations spanning the linear dynamic ranges of both UV-DAD and ESI-MS assay, mean recoveries were always higher than 90% for the different analytes. This method was successfully applied to the analysis of substances under investigations illegally added in cosmetic cream and lotions, sold on internet web sites to prevent hair loss and other hormone-dependent skin diseases, like acne and hirsutism.     

Absorption and disposition of econazole nitrate after application to the skins and vaginas of rabbits.

1. The absorption and tissue distribution of radioactivity has been studied in rabbits after application of a cream containing 10 mg of the 3H-labelled 1-(2,4-dichloro-beta-[(p-chlorobenzyl)oxy]phenethyl) imidazole nitrate (econazole nitrate, Pevaryl) to the normal or abraded skins of rabbits. 2. Approximately one-third of the dose was absorbed through the occluded normal skins of rabbits during 8 days, mainly during 7 to 24 h. In the same time interval, slightly more of the dose was absorbed through the occluded abraded skins of rabbits at slightly greater rates. Co-formulation of triamcinolone acetonide in the cream reduced and delayed the peak rates of absorption through normal and abraded skin, but the extent of absorption during 8 days was similar in the presence or absence of triamcinolone acetonide. 3. After application to normal skin or abraded skin, the peak of mean concentrations in the plasma of 220 ng/ml (range 132-276 ng/ml) or 307 ng/ml (range 270-321 ng/ml), respectively, occurred at 24 h. Tissue distribution of radioactivity was similar after application to normal or abraded skin, and concentrations were highest in the liver, kidneys and gastrointestinal tract (which are the organs of biotransformation and excretion) and also in the adrenals and to a lesser extent in the uterus, ovaries and untreated skin. 4. After application of a cream containing 5 mg of 3H-econazole nitrate to the vaginas of rabbits, approximately one-third of the dose was absorbed during 8-24 h, and rates of excretion were higher through the more permeable vaginal membrane. 5. After vaginal doses of 5 mg, a peak concentration of 209 ng/ml occurred at 6 h in the plasma. Tissue concentrations of radioactivity after vaginal doses were highest in liver, kidneys, gastrointestinal tract, adrenals and ovaries, and the tissue distribution was similar to that observed after cutaneous doses.     

高效液相色谱法测定酮康唑曲安奈德乳膏中酮康唑含量

目的 建立测定酮康唑曲安奈德乳膏中酮康唑含量的方法.方法 采用高效液相色谱法,色谱柱为Shimpack VP-ODSC 18,流动相为甲醇：pH 6.8磷酸盐缓冲液（80：20）,流速为1.0ml·min-1,检测波长为254 nm.结果 酮康唑检测质量浓度线性范围为19.34～116.10 μg·ml-1（r=0.9999）,平均回收率=100.29％,RSD=0.26％.结论 本法专属性好、准确、灵敏,可用于控制酮康唑曲安奈德乳膏的质量.     

HPLC法测定复方醋酸曲安奈德乳膏的含量

目的：建立HPLC法测定复方醋酸曲安奈德乳膏中醋酸曲安奈德和氯霉素的含量。方法：用Hypersil CN（200mm×4．6mm,5μm）色谱柱,以水－甲醇．四氢呋喃（60：28：12）为流动相,流速：1．0ml·min^-1,检测波长为240am。结果：醋酸曲安奈德和氯霉素浓度分别在5．02—100．40μg·ml^-1。（r=1．0000,n=5）及99．73～1994．52μg·ml^-1（r=0．9999,n=5）范围内线性关系良好,平均回收率分别为100．0％（RSD为0．66％）和100．0％（RSD为0．94％）。结论：该方法准确可靠,可用于复方醋酸曲安奈德乳膏中醋酸曲安奈德和氯霉素的含量测定。     

Mouse thymocyte cytolysis of several anti-inflammatory steroid derivatives

For evaluating the cytolytic effects on the mouse thymocytes, four typical anti-inflammatory steroids (dexamethasone, triamcinolone acetonide, prednisolone, hydrocortisone) were selected in this study. When steroids were treated to the mouse thymocytesin vitro cytolysis occurred with dose-dependent fashion and the activities were found to be parallel with the known local anti-inflammatory activities.In vivo thymus atrophogenic activities appeared by the treatment of topical and subcutaneous applications of the derivatives were also found to dose-dependent, but not coincided with the thymocyte cytolytic activitiesin vitro and local anti-inflammatory activity in the case of triamcinolone acetonide. Triamicinolone acetonide induced potent thymocyte cytolysis in vitro, but showed less thymus atrophy.     

Enhanced bioavailability by buccal administration of triamcinolone acetonide from the bioadhesive gels in rabbits

The pharmacokinetics and bioavailability of triamcinolone acetonide were determined to investigate buccal absorption from the mucoadhesive gels in rabbits. The enhancing effect of sodium deoxycholate as an enhancer on the buccal absorption of triamcinolone acetonide from the mucoadhesive gels was evaluated in rabbits. Thus, 2 mg/kg of triamcinolone acetonide was administered from the mucoadhesive gels containing an enhancer (enhancer group) or not (control group) via the buccal routes and compared with intravenous routes (1 mg/kg, i.v. group). AUC of the control, enhancer and i.v group were 2374+/-915, 3778+/-1721 and 3945+/-2085 h ng/ml, respectively, and the absolutive bioavailability of enhancer or i.v to control group were 159.14 or 332.35%, respectively. The average C(max) of control and enhancer group were 263+/-159 and 362+/-201 ng/ml, and the mean T(max) of the control group and enhancer group were 5.00+/-1.67 and 4.33+/-0.82 h, respectively, but there was no significant difference. As the triamcinolone acetonide gels containing sodium deoxycholate as an enhancer was administered to rabbits via the buccal routes, the relative bioavailability showed about 1.59-fold compared with the control group. Buccal administration of triamcinolone acetonide gels containing sodium deoxycholate as an enhancer to rabbits showed a relatively constant, sustained blood concentration with minimal fluctuation.     

高效液相色谱法测定醋酸曲安奈德注射液中醋酸曲安奈德含量

目的建立醋酸曲安奈德注射液中醋酸曲安奈德含量测定的方法。方法采用高效液相色谱法,流动相为甲醇-水（70：30）,流动速度为1.0ml/min,检测波长为240nm。结果醋酸曲安奈德的线性范围为0.0064～0.128mg/ml,线性方程：y=1.8683×10^-6＋5.3174x（r=0.999976,n=7）,回收率99.9%,RSD为0.36%（n=9）。结论采用高效液相色谱法测定醋酸曲安奈德注射液中醋酸曲安奈德含量的方法具有简便、准确、重现性好等优点,可作为该制剂的质量控制方法。     

HPLC法测定复方硝酸咪康唑乳膏的含量

目的：建立高效液相法测定复方硝酸咪康唑乳膏中硝酸咪康唑和醋酸曲安奈德的含量。方法：色谱柱为Hypersil BDS C18柱（250mm×4．6mm,5μm）,流动相为三乙胺溶液（10ml三乙胺加水至1000ml,用磷酸调节pH至2．5）-甲醇-乙腈-四氢呋喃（7：5：4：3）,流速为1ml·min^-1,检测波长为227nm,进样量为20μl。结果：硝酸咪康唑在进样量735．0～24．5μg,醋酸曲安奈德在进样量100．0～2．5μg范围内线性关系良好（r分别为0．9999和0．9999）,平均回收率分别为100．8％（RSD=1．1％）和100．5％（RSD=1．3％）。结论：本方法简便、准确,重复性好,可用于复方硝酸咪康唑乳膏的含量测定和质量控制。     

HPLC法测定复方醋酸曲安奈德滴耳液中醋酸曲安奈德含量

目的：建立HPLC法测定复方醋酸曲安奈德滴耳液中醋酸曲安奈德含量。方法：采用WondaSil^TM C18（250mm×4．6mm,5μm）色谱柱,以甲醇-水（62：38）为流动相,流速1．0ml／min,检测波长240nm。结果醋酸曲安奈德在10．24—30．72μg／ml浓度范围内与吸收度呈良好线性关系（r=0．9998）,平均回收率为100．8％,RSD为1．37％（n=9）。结论：本方法简便、准确、可靠。     

复方更昔洛韦/曲安奈德眼用凝胶的制备及其质量控制

目的:制备复方更昔洛韦/曲安奈德眼用凝胶,并对其进行质量控制。方法:以卡波姆为基质,制备复方更昔洛韦/曲安奈德眼用凝胶。采用高效液相色谱法测定其中更昔洛韦和曲安奈德的含量,并对其外观形状、黏度、渗透压、pH进行检测。结果:制得的眼用凝胶无色澄清透明,外观均一稳定,黏度为92 mpa·s,渗透压为921.66 mosmol/kg,pH为6.91;更昔洛韦和曲安奈德的检测质量浓度线性范围分别为30.3⁹0.9、10.590.9、10.5⁷3.5μg/ml(r=0.999 8),平均回收率分别为99.20%73.5μg/ml(r=0.999 8),平均回收率分别为99.20%⁹9.88%、100.29%99.88%、100.29%¹00.64%,RSD分别为0.81%100.64%,RSD分别为0.81%⁰.90%、0.24%0.90%、0.24%¹.03%(n=3)。结论:该制剂制备方法简单,质量可控。     

HPLC determination of dexamethasone in human plasma and its application to an in vitro release study from endovascular stents

A simple, accurate and precise HPLC assay was developed and validated for determination of dexamethasone in human plasma. Triamcinolone acetonide was used as internal standard (I.S.) and plasma samples were extracted using liquid-liquid extraction with ethyl acetate. Chromatography was performed on a C-18 column with acetonitrile-triple distilled water (28:72% v/v, pH adjusted to 2.3 with phosphoric acid) at a flow rate of 1.2 mL/min and detection wavelength 254 nm. The assay was linear at a concentration range of 0.25-6 microg/mL with recoveries >77%. Precision and accuracy were within the acceptable limits. The method was used to determine dexamethasone release from different material coated endoluminal vascular stents in in vitro human plasma experiments. The results were useful in identifying a good coating material for the stents.     

高效液相色谱法测定复方健疗霜中三组分含量

目的：测定复方健疗霜中曲安奈德、盐酸苯海拉明和硝酸咪康唑的含量。方法：高效液相色谱法,在ＳｈｉｍｐａｃｋＣＬＣ－ｐｈｅｎｙｌ柱上,以甲醇－水相（三乙胺２ｍＬ,加水至３００ｍＬ,磷酸调ｐＨ至７６）为流动相,检测波长：２３０ｎｍ。结果：本文可同时测定三组分的含量。曲安奈德００２０～００８０ｇ·Ｌ－１,盐酸苯海拉明００８０～０３２０ｇ·Ｌ－１,硝酸咪康唑０１６０～０６４０ｇ·Ｌ－１范围内,峰面积与其浓度呈良好线性关系;平均回收率依次为１００４％,ＲＳＤ＝１０２％;１００６％;ＲＳＤ＝０９１％;１００５％,ＲＳＤ＝０６０％。结论：方法简便、快速、准确,可作为样品的检测方法。     

Stability of dexamethasone sodium phosphate in rat plasma

The use of corticosteroid prodrugs in pharmacokinetic studies poses the risk of overestimation of corticosteroid concentrations due to in vitro hydrolysis of prodrugs after sample collection. This study tests the effectiveness of the anticoagulant EDTA as a stabilizer for dexamethasone sodium phosphate (DSP) in rat plasma and provides simultaneous HPLC analysis of DSP and dexamethasone. An already developed ion-paired reversed-phase HPLC assay for simultaneous measurement of corticosteroid phosphate ester prodrugs and their active steroids was applied in this study. This assay was used for analyzing samples from an in vitro DSP hydrolysis study in rat plasma. In agreement with allometric principles, the prodrug hydrolysis occurred at a much faster rate (in vitro half-life of 1.75 h) in rat plasma as compared with previously reported prodrug hydrolysis half-life of 10-12 h in sheep and human plasma. The in vitro degradation of the prodrug in rat plasma was greatly minimized in plasma containing EDTA at the concentration commonly used an anticoagulant. This study demonstrates that artifacts in pharmacokinetic profiles of corticosteroids due to in vitro prodrug hydrolysis can be greatly minimized by collecting blood samples with EDTA as the anticoagulant.     

A mass balance study to evaluate the biotransformation and excretion of [14C]-triamcinolone acetonide following oral administration

The principle objective of this study was to characterize the absorption, metabolism, and disposition of orally administered [14C]-triamcinolone acetonide. Six healthy male subjects each received a single 100 microCi (approximately 800 micrograms) oral dose of [14C]-triamcinolone acetonide. Plasma, urine, and fecal samples were collected at selected times and analyzed for triamcinolone acetonide and [14C]-derived radioactivity. Plasma protein binding of triamcinolone acetonide was also determined. Metabolite profiling and identification were carried out in plasma and excreta. Principle metabolites were assessed for activity with in vitro anti-inflammatory models. [14C]-triamcinolone acetonide was found to be systemically absorbed following oral administration. The presystemic metabolism and clearance of triamcinolone acetonide were extensive, with only a small fraction of the total plasma radioactivity being made up of triamcinolone acetonide. Little to no parent compound was detected in the plasma 24 hours after administration. Most of the urinary and fecally [14C]-derived radioactivity was also excreted within 24 and 72 hours postdose, respectively. Mean plasma protein binding of triamcinolone acetonide was constant, predictable, and a relatively low 68% over a 24-fold range of plasma concentrations. Three principle metabolites of triamcinolone acetonide were profiled in plasma, urine, and feces. These metabolites were identified as 6 beta-hydroxy triamcinolone, 21-carboxylic acid triamcinolone acetonide, and 6 beta-hydroxy-21-oic triamcinolone acetonide. All three metabolites failed to show any concentration-dependent effects in anti-inflammatory models evaluating IL-5-sustained eosinophil viability and IgE-induced basophil histamine release.     

LC-MS/MS determination of betamethasone and its phosphate and acetate esters in human plasma after sample stabilization

Two specific liquid chromatography-mass spectrometric (LC-MS/MS) assays were developed and validated for the determination of betamethasone (BET), and its acetate (BA) and phosphate (BP) esters. The plasma and the blood used for the development and validation of these two methods were previously stabilized. Liquid-liquid extraction techniques were used after the addition of prednisolone as internal standard (IS). Samples were chromatographed using C8 column, while mass detection was carried out by electrospray ionization in the positive mode (ESI+). The method was proved linear over a working range 0.50-50.00 ng/ml for BET (r² > 0.99), while BA linear range was 1.0-20.0 ng/ml (r² > 0.99). Sensitivity was determined as 0.50 ng/ml for BET and 1.00 ng/ml for BA. Betamethasone phosphate LC-MS/MS method involved solid phase extraction after the addition of prednisolone phosphate as (IS). Separation was carried out using C18 column, while detection was by ESI+. The method showed good linearity over the working range 2.0-200.0 ng/ml (r² > 099). Both methods were applied to determine BET, BA and BP in plasma samples obtained for pharmacokinetics studies in human.