共查询到20条相似文献,搜索用时 15 毫秒
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《Drug development and industrial pharmacy》2013,39(14-16):2475-2489
AbstractPilocarpine (Pi), a widely used anti-glaucoma drug, is characterized by a very low bioavailability, due to poor corneal penetration and extensive precorneal loss. Purpose of the present study was the preparation and “in vivo” evaluation of a series of liquid formulations containing salts (or ionic complexes) of Pi with soluble polyanionic polymers of natural, synthetic or semi-synthetic origin. It was speculated that since to some of the polymers have been attributed muco-adhesive properties, they might favour the preocular retention of the ionically bound drug, and enhance its bioavailability. The polymers submitted to investigation were a) hyaluronic acid (HA); b) poly-(galacturonic acid) (PGA); c) Mesoglycan (MG, a complex mixture of mucopolysaccharides); d) Carboxymethylchitin (CMCh) and d) two poly(acrylic acids) of different molecular weight (PAA1 and PAA2). Aqueous solutions of the Pi polymer salts, each containing 1.53% w/w Pi base (equivalent to 2.0% Pi nitrate) were tested for miotic activity in albino rabbits, using as reference an aqueous, 2% solution of Pi nitrate, either as such or viscosized with 1.5 and 5.0% poly(vinyl alcohol), (PVA). All polymeric solutions enhanced, in some cases to a statistically significant extent, the bioavailability of the drug with respect to the reference solutions. The relevance of viscosity effects, and of possible muco-adhesive phenomena to the bioavailability of Pi from the salt-vehicles are discussed 相似文献
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《Drug development and industrial pharmacy》2013,39(6):801-805
The stability of pilocarpine and pilocarpine-timolol eyedrop preparations available on the Argentine market was studied. A high-performance liquid chromatographic method that allows the estimation of pilocarpine in the presence of degradation products was used for the study according to the preestablished design. It was found that pilocarpine solutions are stable, while pilocarpine in association with timolol shows significant degradation. 相似文献
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C. Pilatti M. del C. Torre C. Chiale M. Spinetto 《Drug development and industrial pharmacy》1999,25(6):801-805
The stability of pilocarpine and pilocarpine-timolol eyedrop preparations available on the Argentine market was studied. A high-performance liquid chromatographic method that allows the estimation of pilocarpine in the presence of degradation products was used for the study according to the preestablished design. It was found that pilocarpine solutions are stable, while pilocarpine in association with timolol shows significant degradation. 相似文献
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合成表征了5种磷酸酯类离子液体,并将其用于溶解木质素。结果表明,离子液体1,3-二甲基咪唑磷酸甲酯盐[Mmim]DMP对木质素的溶解性能最佳,在70℃搅拌120 min,木质素溶解度可达45%。扫描电镜(SEM)、X射线衍射(XRD)和红外光谱(FT-IR)表征结果显示离子液体在木质素溶解过程中并未使木质素发生衍生化反应,但经离子液体溶解再生后,木质素的形貌均发生了显著变化,离子液体溶解性能越强,所得再生木质素颗粒越均匀、分散性越好且弥散衍射特征越强烈。此外,回收所得离子液体重复使用5次后,对木质素仍有较好的溶解性能。 相似文献
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构建离子液体1-乙基-3-甲基咪唑醋酸盐[EMIM]OAc与纤维素的均相体系,采用酶原位降解法,以3,5-二硝基水杨酸法表征降解效果,考察各因素的影响确定最佳工艺条件:6.6 g 3%(质量分数)原溶液与4 mL pH4.6柠檬酸钠缓冲溶液组成均相体系、6 mg酶、50℃、26 h,酶解率迭78.5%,比非均相下提高了... 相似文献
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氨基酸离子液体对壳聚糖溶解性能的影响 总被引:3,自引:0,他引:3
合成了一系列氨基酸类离子液体,从中筛选出对溶解壳聚糖具有良好性能的离子液体——甘氨酸盐酸盐离子液体。在常温常压下考察了该离子液体1%~10%水溶液对壳聚糖的溶解能力,溶解壳聚糖能力最大能达到6.32%(质量分数,下同)。对离子液体重复使用5次后,溶解能力没有明显下降。采用X射线衍射(XRD)和红外光谱(FT-IR)对再生的壳聚糖进行表征,结果表明,壳聚糖在溶解过程中没有发生衍生化。甘氨酸盐酸盐离子液体水溶液是壳聚糖的良溶剂。 相似文献
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咪唑基离子液体对聚丙烯抗静电性能的影响 总被引:3,自引:0,他引:3
以咪唑基离子液体(im i-IL)为抗静电剂与聚丙烯(PP)熔融共混制备出PP/im i-IL共混复合材料,并对材料的抗静电性能、抗静电耐擦洗性能和力学性能进行了测试。结果表明,咪唑基离子液体在显著提高PP的抗静电性能和抗静电剂耐擦洗性能的同时,材料的冲击强度虽略有下降,但拉伸强度提高。 相似文献
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利用化学还原方法,加入不同量的离子液体1-甲基-3-乙基咪唑硫酸乙酯盐,制备了不同大小的金属铜的纳米摘要粒子。采用X射线衍射和透射电子显微镜对所制备的样品进行了结构表征。结果表明,两个样品中的粒子都具有五边形和六边形结构,粒径约为200~300nm,离子液体不但作为分散剂影响粒子的大小,而且有一定的防氧化作用。 相似文献
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Zhidong Liu Weisan Pan Shufang Nie Libo Zhang Xinggang Yang Jiawei Li 《Drug development and industrial pharmacy》2013,39(10):969-975
ABSTRACTThe poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid precorneal elimination of the drug may be overcome by the use of a gel system. The present work describes the formulation and evaluation of an ophthalmic delivery system containing an antibacterial agent, enoxacin, based on the concept of ophthalmic sustained gel, in which 2-hydroxypropyl-beta-cyclo-dextrin (HP-β-CD) was used as a penetration enhancer in combination with hydroxypropylmethylcellulose (Methocel F4M) which acted as a vehicle. The developed formulation was therapeutically efficacious, nonirritant, and provided sustained release of the drug over 8 h period in vitro and 7 h period in vivo. The developed system is a viable alternative to conventional eye drops. 相似文献
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《Drug development and industrial pharmacy》2013,39(14-16):2621-2637
AbstractThe present investigation is concerned with the development and “in vivo” evaluation of a long-acting ocular vehicle for the α-adrenergic blocking drug dapiprazole (DAP). The approaches tested for prolonging the activity were a) salification of the drug base with polygalacturonic acid (PGA), and b) formulation as a highly viscous hydrogel. The vehicles prepared by applying (singly or in combination) these techniques, and two reference aqueous vehicles containing DAP-HCl were submitted to a series of biological tests on rabbits (miosis and reversion of mydriasis). When compared with an aqueous solution an aqueous solution, reconstituted prior to use from a freeze-dried formulation (marketed in Italy as GlamidoloR, Angelini)The topical administration of ophthalmic drugs from aqueous solutions (collyria) is characterized by a poor bioavailability and a short duration of action, as a result of a series of concomitant physiological factors (induced lacrimation, tear turnover, solution drainage etc.) which concur in removing the solution from the eye. These factors have been widely investigated and detailed in the relevant literature, and several approaches to extend the ocular residence time of topically applied medications have been reported (4). In the present study two such approaches, namely, a) salification of the basic drug with a polyanionic polymer and b) increased vehicle viscosity, were applied to the development of a long-acting ocular formulation for DAP. The effect of the said manipulations on the biological activity of a series of DAP vehicles was submitted to a preliminary verification “in vivo”, by performing miosis and reversion of tropicamide-induced mydriasis tests in rabbits 相似文献
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《Drug development and industrial pharmacy》2013,39(5):471-477
AbstractTwenty-three potential nonaqueous parenteral vehicles were evaluated for tissue irritation in chicken pectoral muscle. Benzyl benzoate, 1,3-butylene glycol, ethyl oleate, glyceryl triacetate, sesame oil and sesame oil: benzyl benzoate (1:1) were found to cause minimal tissue irritation. 相似文献
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DMSO对纤维素在咪唑型离子液体中溶解性能的影响 总被引:1,自引:0,他引:1
本文通过向传统离子液体中添加助溶剂DMSO来增强离子液体对纤维素的溶解效果。系统研究了DMSO添加量对纤维素溶解性能的影响,结果表明50℃下随着DMSO添加量的增大,纤维素的溶解程度增加,当DMSO添加量为50%时溶解效果最佳。采用电导率测试研究了DMSO与离子液体的作用机理,并通过FT-IR、XRD、TGA、SEM以及力学性能测试等方法对添加不同量DMSO溶剂溶解再生后的纤维素膜进行了分析,结果表明添加DMSO后溶剂仍为纤维素的直接溶剂,溶解再生后纤维素晶型由Ⅰ转变为Ⅱ型,并且随着DMSO添加量的增加,溶剂对纤维素分子链及结晶区的破坏能力增大,从而导致再生纤维素结晶度、抗拉强度及聚合度相对纯离子液体再生的有所降低。 相似文献
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离子液体具有优良的物理化学性能,受到研究者的广泛关注.近年来,有关离子液体在可逆加成-断裂链转移(RAFT)聚合反应中的应用有大量的研究报道.作为溶剂,离子液体能溶解一些较难溶解的聚合物,如纤维素和壳聚糖等,可以为聚合反应提供较好的反应环境;作为单体,通过RAFT聚合可制备出聚合离子液体均聚物或带有聚合离子液体链段的嵌段聚合物,可以应用于燃料电池电解质膜、太阳能电池、催化、分离及吸附剂等领域;离子液体还可以作为表面活性剂,应用于RAFT的乳液聚合或细乳液聚合,有效地稳定和控制聚合物颗粒大小.从溶剂、单体和表面活性剂方面出发,简单总结了离子液体在RAFT聚合反应中的应用. 相似文献
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M.P.Tosi 《材料科学技术学报》1999,15(4):303-306
1.BackgroundandOutlineThebindingenergy0fac0mpoundsuchasNaClcanberegardedt0alargeextentasarisingfro111trans-ferofanelectr0nfromthehalogent0themetalatom.InanearlyseminalpaperB0rnandNIa3er[']prop0sedam0delwhichattributesthec0hesion0fanalkalihalidecrystalt0theCoul0mbinteractionsbetweenionscarryingintegerchargesandascribestheequilib-riumstateatgiventemperatureandpressuret0aba1-ancebetweenthenetCoul0mbattactionsandquan-talcl0sed-shelloverlaprepulsions.Thelattershowexp0nentialdecaywithincreasingin… 相似文献