盐酸丁螺环酮凝胶喷鼻剂在大鼠体内的药动学性质考察

［摘要］　目的：对盐酸丁螺环酮凝胶喷鼻剂在大鼠体内的药动学性质进行考察，评价其作为鼻腔给药系统的应用价值。方法：将15只大鼠随机分为3组，分别进行静脉给药、灌胃给药及鼻腔给药，剂量均为10 mg&#8226;kg-1，颈动脉取血后用HPLC法测定各时间点血浆中盐酸丁螺环酮及其活性代谢物1-(2-嘧啶基)哌嗪的浓度，用3P87程序软件处理后，以t检验对药动学参数进行显著性检验。结果：鼻腔给药组活性代谢物1-(2-嘧啶基)哌嗪的AUC值与静脉给药组比较，差异无统计学意义［（506.19±59.35）vs（522.14±108.90）nmol&#8226;mL-1&#8226;min，P>0.05］；但显著低于灌胃给药组［（506.19±59.35）vs（716.70±67.10）nmol&#8226;mL-1&#8226;min，P<0.05］。盐酸丁螺环酮大鼠鼻腔给药吸收快，其绝对生物利用度为（83.71±7.66）%，相对于灌胃给药的生物利用度为（2 039.74±186.77）%。结论：盐酸丁螺环酮鼻腔给药可以显著提高口服给药的生物利用度，有望制成凝胶喷鼻剂。     

通过体外自乳化性能及体内药代动力学评价优化葛根素自乳化制剂

本文将水不溶性药物葛根素制备成自乳化制剂。测定了葛根素在不同油相及表面活性剂的溶解度，结果表明葛根素在油酸、Tween 80中的溶解度较好，1，2-丙二醇不但能增加药物的溶解度，而且能够提高自乳化能力。以油酸为油相，Tween 80为表面活性剂，1，2-丙二醇为助表面活性剂，配制一系列混合物，通过绘制三元相图得到自乳化区，考察不同自乳化处方的自乳化性质，采用激光粒度散射仪测定乳化后粒子大小，在体外评价基础上选择较好的3个处方进行比格犬体内药动学研究，比较不同处方自乳化制剂在比格犬体内的生物利用度包括药代动力学参数Cmax， Tmax， AUC0-t。结果表明处方2和处方3的AUC0-t值［(5.201±0.511) ng·mL^-1·h， (5.174±0.498) ng·mL^-1·h］和Cmax值［(1.524±0.125) ng·mL^-1， (1.513±0.157) ng·mL^-1］显著高于处方4［(3.013±0.623) ng·mL^-1·h， (0.939±0.089) ng·mL^-1］，通过体内研究结果获得较优处方为油酸(17.5%)、Tween 80(34.5%)、1，2-丙二醇(34.5%)。自乳化释药系统提供了水不溶性药物口服给药的新途径。     

加替沙星的药理和临床应用

加替沙星 (ｇａｔｉｆｌｏｘａｃｉｎ，ＡＭ -１１５５，ＣＧ５５０１)是一种新型广谱８ -甲氧氟喹诺酮抗生素。口服易吸收 ,静注与口服具有生物等效性［１］。加替沙星对Ｇ 细菌、衣原体、支原体、分枝杆菌和厌氧菌等都有强大的杀菌作用 ［２］,临床上对上述病原体引起的各种感染治疗均有效。１药代动力学口服加替沙星４００ｍｇ ,达峰时间 (１ ４±０ ８)ｈ ,峰值浓度(Ｃｍａｘ) :(３ ８±０ ５)ｍｇ／Ｌ ;药 -时曲线下面积 (ＡＵＣ０→∞) :(３３ ５±５ ９) μｇ／(ｈ·ｍｌ) ［３］,绝对生物利用度为９６ % ［１］,Ｔ１／２ 为２ ７…     

纳洛酮对血管性痴呆大鼠学习和记忆能力的影响

目的 研究纳洛酮对血管性痴呆大鼠空间学习和记忆能力减退的防治作用及作用机制。方法 将30只SD大鼠随机分为模型组、给药组和对照组各10只。结扎模型组和给药组大鼠双侧颈总动脉，以制作血管性痴呆模型。模型制作成功后，给药组腹腔注射纳洛酮，0.8 mg·kg^-1·d^-1；模型组腹腔注射等量0.9%氯化钠注射液。对照组大鼠给予假手术，不结扎双侧颈总动脉，腹腔注射等量0.9%氯化钠注射液。均连续给药7 d。8周后进行Morris水迷宫试验，观察3组大鼠隐匿平台逃避潜伏期、去平台后每分钟穿越平台所在位置的次数、恢复平台后从一固定点爬上平台所用的时间，并做病理学检查。结果 模型组大鼠隐匿平台逃避潜伏期［(21.26±741) s］明显长于对照组［(7.80±4.70) s］和给药组［(8.10±2.93) s］(均P＜0.01)，但对照组和给药组之间差异无显著性；去除平台后，模型组大鼠每分钟穿越平台所在位置的次数［(4.44±1.74)次］明显少于对照组［(8.45±1.19)次］和给药组［(8.00±1.17)次］(均P＜0.01)，对照组和给药组差异无显著性；恢复平台后3组大鼠从一固定点爬上平台所用的时间无明显差别；病理检查结果显示，模型组大鼠脑海马(CA)1区锥体细胞数［(43.68±17.29)个］较对照组［(124.51±14.18)个］和给药组［(113.36±13.15)个］明显减少(均P＜0.01)。结论 纳洛酮对血管性痴呆大鼠空间学习和记忆能力减退有明显的防治作用。其机制可能与纳洛酮抑制大鼠脑CA1区锥体细胞丢失和保护脑细胞作用有关。     

格拉司琼鼻喷雾剂在比格犬体内的相对生物利用度研究

目的:对格拉司琼鼻喷雾剂在比格犬体内的药代动力学进行研究,评价其相对生物利用度。方法:比格犬采用随机、自身交叉给药,分别口服片剂、鼻腔给喷雾剂,用HPLC荧光方法测定格拉司琼血浆浓度。结果:比格犬分别单剂量口服片剂、鼻腔给喷雾剂2 mg后的主要药代动力学参数tmax分别为1.50±0.41和0.31±0.13 h,Cmax分别为6.45±1.15和11.93±1.33 ng.ml-1,AUC0-12分别为25.14±3.75和27.76±3.46 ng.h.ml-1,AUC0-∞分别为28.46±4.17和31.46±3.43 ng.h.ml-1,鼻喷雾剂对片剂的相对生物利用度为(111.9±18.9)%。结论:格拉司琼鼻喷雾剂比片剂吸收快,生物利用度较高。     

四氢小檗红碱及其前药的比格犬药代动力学研究

目的建立同时定量检测比格犬全血中抗焦虑新药四氢小檗红碱(THB)及其前药9-乙酰四氢小檗红碱硫酸盐(ATHBS)的LC-MS/MS方法,并研究四氢小檗红碱在比格犬体内的药代动力学及生物利用度。方法建立检测全血中THB和ATHBS的LC-MS/MS方法,进行专属性、线性、回收率、稳定性、精密度和准确度等方法学验证。比格犬单次口服和静脉注射3 mg.kg-1ATHBS后考察了前药与活性代谢产物THB的血药浓度-时间变化,应用WinNonlin软件得到药代动力学参数和口服生物利用度。结果 ATHBS和THB在2～2 000μg·L-1的浓度范围内呈良好的线性(r>0.9985),定量下限均为2μg·L-1。THB和ATHBS的回收率分别大于78.74%和75.52%,日内和日间精密度(RSD)均在10.79%之内,准确度(RE)在-10.3%～3.92%的范围内。比格犬单次静注和口服ATHBS后,前药均能快速转化成为活性产物,血中浓度在60 min降至检测限之下。静注组THB在2 min达峰,Cmax为(605.99±102.88)μg·L-1,消除半衰期T12为(7.03±1.77)h,AUC(0-t)为(718.64±143.01)h·μg·L-1。口服组THB在15min达到(77.71±26.60)μg.L-1的峰值,药-时曲线在6 h出现第2个小峰,T 12为(5.89±3.95)h,AUC(0-t)为(179.62±91.64)h·μg·L-1,口服生物利用度为26.2%。结论建立的LC-MS/MS定量方法快速、简便、灵敏,可用于同时研究前药和THB的药代动力学。比格犬口服或静注ATHBS后,前药在体内可快速转化成为活性产物,THB达峰迅速,血药浓度消除较快,口服生物利用度较好。     

不同剂量丙泊酚微乳注射液在Beagle犬体内的药动学参数比较

目的:比较3种不同剂量丙泊酚微乳注射液在Beagle犬体内的药动学参数,并了解其相关性。方法:取Beagle犬12只随机均分为丙泊酚微乳注射液高、中、低剂量组(6、4、2mg·kg-1),静脉注射相应药物,采用高效液相色谱-荧光法检测各组犬给药前及给药后480min内血药浓度,1周和2周后3组犬交叉给药,给药剂量、方法一致,并计算其药动学参数。结果:高、中、低剂量组丙泊酚微乳注射液在犬体内的药-时曲线均符合静注二室模型,其t1/2β分别为(33.02±10.00)、(31.25±23.27)、(53.64±21.78)min,AUC0～480min分别为(60.00±12.50)、(26.90±11.61)、(19.61±3.39)μg·min·mL-1。结论:不同剂量丙泊酚微乳注射液体内消除率和消除方式类似,AUC0～480min与剂量呈正相关。     

乌苯美司在犬体内的药动学和绝对生物利用度

建立了RP-HPLC法在258nm测定犬血浆中乌苯美司的浓度,方法定量限为0．625μg／ml,日内、日间差小于5．0％, 平均同收率大于95．0％。采用双周期自身交叉设计,在7条Beagle犬中进行口服及静脉给药的药物动力学研究,清洗期为 8d。Beagle犬静注乌苯美司200mg后的药-时曲线符合三室模型,口服给药的C_(max)为(31．54±5．164)μg/ml,T_(max)为(1．50 ±0．41)h,T_(1/2)为(1．53±0．48)h,AUC_o→t为(92．85±10．74)μg·ml~(1-)·h。平均绝对生物利用度为(67．61±11．75)％。     

兔血浆中盐酸利多卡因的测定及不同给药途径的药动学研究

建立了HPLC法测定兔血浆中利多卡因的浓度,并研究家兔经不同途径给药后的药动学.采用C18柱,流动相为甲醇-0.01mol/L NaH2PO4溶液(pH 2.1)(30∶70),检测波长263nm.血浆样品经蛋白沉淀后进样测定.家兔分别给予10mg盐酸利多卡因静脉注射剂、鼻腔凝胶剂、鼻腔溶液剂和口服溶液剂后,t1/2分别为(62.06±8.72)、(63.60±11.32)、(59.16±5.58)和(59.55±7.63)min,AUC0→180min分别为(1233.74±390.82)、(1230.38±344.32)、(721.09±268.60)和(334.93±120.97)μg·min·ml-1.后三者的Cmax分别为(18.36±3.55)、(13.68±2.58)和(4.64±1.77)μg/ml,绝对生物利用度分别为(99.73±20.92)%、(58.45±14.10)%、(27.15±6.47)%.方差分析和双单侧t检验结果显示,鼻腔凝胶剂与静脉注射剂吸收程度等效.     

HPLC/MS法研究左旋黄皮酰胺及其代谢物在Beagle犬血浆中的药代动力学HPLC/MS法研究左旋黄皮酰胺及其代谢物在Beagle犬血浆中的药代动力学

目的用HPLC/MS法研究左旋黄皮酰胺［(-)-clau］及其代谢物6-羟基-黄皮酰胺(6-OH-clau)在Beagle犬血浆中的药代动力学过程。方法Beagle犬灌胃左旋黄皮酰胺30 mg·kg^-1，采集静脉血样，血浆经乙酸乙酯萃取分离后，用HPLC/MS选择性正离子检测内标(格列吡嗪，［M+H］⁺，m/z 446)法测定左旋黄皮酰胺(［M+H］⁺，m/z 298)及6-羟基-黄皮酰胺(［M+H-H₂O］⁺，m/z 296)的浓度，以甲醇-水-冰醋酸(60∶40∶0.8)为流动相，流速1.0 mL·min^-1。用3P97软件计算药代动力学参数。结果左旋黄皮酰胺和6-羟基-黄皮酰胺分别在1.0～200 ng·mL^-1和0.2～40.0 ng·mL^-1线性关系良好(r>0.999)，萃取回收率均大于85%。原药及其代谢物的体内过程均符合二室模型；左旋黄皮酰胺及6-羟基-黄皮酰胺的C_max分别为(21±10) ng·mL^-1和(3.9±2.2) ng·mL^-1；T_max分别为(0.8±0.5) h和(1.3±0.5) h；T_1/2α分别为(0.9±0.6) h和(1.4±0.6) h；T_1/2β分别为(19±23) h和(13±12) h；AUC_{0-24 h}分别为(69±14) h·ng·mL^-1和(12±7) h·ng·mL^-1。结论Beagle犬灌胃左旋黄皮酰胺后迅速吸收，血药浓度一相消除很快，但末端消除较慢；其代谢物6-羟基-黄皮酰胺血药浓度经时过程与左旋黄皮酰胺相似，但血药浓度相对较小。     

Distribution of nimodipine in brain following intranasal administration in rats

AIM: To determine whether nasally applied nimodipine (NM) could improve its systemic bioavailability and be transported directly from the nasal cavity to the brain. METHODS: NM was administered nasally, intravenously (iv), and orally to male Sprague-Dawley rats. At different times post dose, blood, cerebrospinal fluid (CSF), and brain tissue samples were collected, and the concentrations of NM in the samples were analyzed byHPLC. RESULTS: Oral systemic bioavailability of NM in…     

Pharmacodynamics of acute intranasal administration of verapamil: comparison with i.v. and oral administration

The present study was conducted in order to examine the intranasal administration of verapamil and compare this route to oral and intravenous administration in a 3 way crossover protocol in five dogs. Unanesthetized, adult mongrel dogs were given verapamil intravenously (0.5 mg/kg), orally (2.5 mg/kg) and intranasally (0.75 mg/kg) with at least a 3-4 day washout period between each administration. Blood samples were collected over a 10 hour period and analyzed for verapamil using HPLC with fluorescence detection. A lead II ECG was monitored to determine the effects of verapamil on heart rate and P-R interval. Following intravenous administration, verapamil was distributed according to a two compartment model. Bioavailability (corrected for dose and elimination rate constant) following intranasal administration (36% +/- 7%) was approximately 3 fold that after oral administration (13% +/- 3%). Absorption from the nasal cavity appeared instantaneous compared to an absorption half-life of 50 +/- 6 min after oral administration. All three routes of administration resulted in significant increases in heart rate and increases in the P-R interval. Maximal P-R interval prolongation occurred after peak plasma concentrations of verapamil. The results of this study suggest that the intranasal route is a viable alternative route of administration for verapamil.     

Bioavailability and mammary excretion of bisphenol a in Sprague-Dawley rats.

This study reports the absolute oral bioavailability and mammary excretion of bisphenol A in rats. The oral bioavailability was determined after administration of relatively low iv (0.1 mg/kg) and oral (10 mg/kg) doses of bisphenol A to rats. After iv injection, serum levels of bisphenol A declined biexponentially, with the mean initial distribution and terminal elimination half-lives being 6.1 +/- 1.3 min and 52.5 +/- 2.4 min, respectively. The systemic clearance (Cls) and the steady-state volume of distribution (Vss) averaged 107.9 +/- 28.7 m/min/kg and 5.6 +/- 2.4 L/kg, respectively. Upon oral administration, the maximum serum concentration (Cmax) and the time to reach the maximum concentration (Tmax) were 14.7 +/- 10.9 ng/ml and 0.2 +/- 0.2 h, respectively. The apparent terminal elimination half-life of bisphenol A (21.3 +/- 7.4 h) after oral administration was significantly longer than that after iv injection, indicating the flip-flop of the absorption and elimination rates. The absolute oral bioavailability of bisphenol A was low (5.3 +/- 2.1%). To determine the extent of mammary excretion, bisphenol A was given by simultaneous iv bolus injection plus infusion to steady state at low, medium, and high doses. The steady-state serum levels of bisphenol A were linearly increased with higher dosing rates. The systemic clearance (mean range, 119.2-154.1 ml/min/kg) remained unaltered over the dosing rate studied. The levels of bisphenol A in milk exceeded those in serum, with the steady-state milk to serum concentration ratio being 2.4-2.7.     

Pharmacokinetics of the trichothecene mycotoxin verrucarol in dogs

Verrucarol is a simple trichothecene which is structurally related to T-2 and HT-2 toxins. Several macrocyclic trichothecenes which are ester derivatives of verrucarol possess antitumor activity. The pharmacokinetics of verrucarol has been studied in eight dogs following iv and oral administrations (0.4 and 0.8 mg/kg, respectively). The iv study showed that verrucarol has a mean (+/- SD) clearance of 11 +/- 5.5 mL/min/kg, a volume of distribution of 1.2 +/- 0.6 L/kg, and a terminal half-life of 1.6 +/- 0.5 h. Following oral administration, the absolute bioavailability of verrucarol was 44 +/- 33%, and its terminal half-life was similar to that obtained after iv administration. In comparison with T-2 and HT-2 toxins, verrucarol has a longer half-life and a lower clearance, and its liver extraction ratio is about one third of that of T-2 and HT-2 toxins. Therefore, verrucarol is less susceptible to a liver first-pass effect and its partially absorbed after oral administration. These characteristics make verrucarol the first partially absorbed trichothecene whose pharmacokinetics was investigated following oral administration.     

Central nervous system kinetics of atenolol and metoprolol in the dog during long term treatment

Beagle dogs with catheters chronically implanted into the lateral cerebral ventricle were used to study the distribution of atenolol and metoprolol between the cerebrospinal fluid (CSF) and blood plasma over a 24-hr period during long term treatment. The concentration of atenolol declined more slowly in CSF than in blood plasma and the CSF/plasma ratio of atenolol (after iv administration for 7 days) increased from 0.08 +/- 0.02 (2 hr after dose) to 0.83 +/- 0.14 (24 hr after dose) (mean +/- SD). Furthermore, the CSF concentration of atenolol, relative to the plasma concentration, increased during repeated drug administration. The CSF/plasma ratio 24 hr after an iv dose was 0.48 +/- 0.12 on day 1 and 0.83 +/- 0.14 on day 7. The CSF concentration of the more lipophilic beta 1-adrenoceptor antagonist metoprolol was almost the same as the concentration of the drug in blood plasma. After 7 days of oral treatment, the CSF/plasma ratio of metoprolol 24 hr after dosing was 0.81 +/- 0.10. The regional CSF concentration of atenolol along the neuraxis was determined in anaesthetized dogs after acute iv administration of the drug. The atenolol concentration in CSF from the lateral cerebral ventricle was similar to that in the cisterna magna but lower than the concentration in CSF sampled from the lumbar region. It is concluded that the CSF concentration of the moderately lipophilic beta 1-adrenoceptor antagonist metoprolol equilibrates with the plasma concentration of the drug more rapidly compared with the hydrophilic drug atenolol.     

Absorption of clonazepam after intranasal and buccal administration.

Serum concentrations of clonazepam after intranasal, buccal and intravenous administration were compared in a cross-over study in seven healthy male volunteers. Each subject received a 1.0 mg dose of clonazepam intranasally and buccally and 0.5 mg intravenously. A Cmax of 6.3 +/- 1.0 ng ml-1 (mean; +/- s.d.) was measured 17.5 min (median) (range 15-20 min) after intranasal administration. A second peak (4.6 +/- 1.3 ng ml-1) caused by oral absorption was seen after 1.7 h (range 0.7-3.0 h). After buccal administration a Cmax of 6.0 +/- 3.0 ng ml-1 was measured after 50 min (range 30-90 min) with a second peak of 6.5 +/- 2.5 ng ml-1 after 3.0 h (range 2.0-4.0 h). Two minutes after i.v. injection of 0.5 mg clonazepam the serum concentration was 27 +/- 18 ng ml-1. It is concluded that intranasal clonazepam is an alternative to buccal administration. However, the Cmax of clonazepam after intranasal administration is not high enough to recommend the intranasal route as an alternative to intravenous injection.     

Effect of piracetam on cerebral blood flow and somatosensory evoked potential during normotension and hypotensive ischemia in cats

The effect of piracetam (Nootrop), 200 mg/kg body weight, on cerebral blood flow (CBF) and somatosensory evoked potential (EP) was studied in a control group (9 cats, mean arterial blood pressure (MABP) = 113.1 +/- 12,63 mmHg, CBF = 71.0 +/- 24.16 ml/100 g/min) and in another group of 11 cats, in which CBF was reduced to 52.2 +/- 20.17 ml/100 g/min by hemorrhagic hypotension (MABP = 55.9 +/- 18.95 mmHg). Piracetam did not affect CBF significantly in the normotensive group, but decreased the EP slightly. The decrease of the surface negative (N1) wave of the EP reached a significant level 10 min (9.9 +/- 12.05%) and 30 min (15.6 +/- 13.05%) after piracetam. In contrast, CBF and EP were increased by piracetam in the hypotensive group: CBF was significantly improved 10 min (32.0 +/- 64.74%) and 30 min (28.8 +/- 45.11%), and N1 10 min (23.0 +/- 26.47%) after piracetam, while the enhancement of the surface positive wave (P1) of the EP reached a significant level during the entire observation period of 90 min. The results indicate a beneficial action of piracetam on brain tissue whose function is impaired by deficient blood supply.     

The brain targeting efficiency following nasally applied MPEG-PLA nanoparticles in rats

The aim of this study was to encapsulate nimodipine (NM) within methoxy poly(ethylene glycol)-poly(lactic acid) (MPEG-PLA) nanoparticles and to investigate its brain targeting efficiency following intranasal administration. NM-loaded nanoparticles, prepared through an emulsion/solvent evaporation technique, were characterized in terms of size, zeta potential, NM loading and in vitro release. The nanoparticles were administered intranasally to rats, and the concentrations of NM in blood, cerebrospinal fluid (CSF) and brain tissues were monitored. The contribution of the olfactory pathway to the uptake of NM in the brain was determined by calculating the brain/plasma concentration ratios and "brain drug direct transport percentage (DTP)" following intranasal administration of the nanoparticles and the solution formulation. The results showed that MPEG-PLA nanoparticles had a mean particle size of 76.5 +/- 7.4 nm, a negative surface charge and a 5.2% NM loading. In vitro release was moderate under sink conditions. The intranasal administration of nanoparticles resulted in a low but constant NM level in plasma. The ratio of AUC values of the nanoparticles to the solution was 1.56 in CSF. The olfactory bulb/plasma and CSF/plasma concentration ratios were significantly higher (P < 0.05) after application of nanoparticles than those of the nasal solution, except the ratio in olfactory bulb at 5 min. Furthermore, nasally administered nanoparticles yielded 1.6-3.3-fold greater DTP values in CSF, olfactory bulb and other brain tissues compared to nasal solution. Thus, MPEG-PLA nanoparticles demonstrated its potential on improving the efficacy of the direct nose-brain transport for drugs.