新型眼用硝酸毛果芸香碱六角液晶凝胶的制备和评价

目的 本研究以硝酸毛果芸香碱(PN)为模型药,以植烷三醇(PHYT)/三辛酸甘油酯(TAG)/水三元系统制备六角相液晶(HⅡ)凝胶,通过眼部给药提高PN的眼用生物利用度.方法 采用偏光显微镜(CPLM)、小角X射线散射仪(SAXS)和流变学对HⅡ凝胶的内部结构进行表征;通过体外释放和离体角膜渗透对HⅡ凝胶的体外行为进行...     

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??OBJECTIVE To prepare ion-sensitive ophthalmic in situ gel containing bendazac lysine (BDZL-ISG) and preliminarily study its rheological behavior, in vitro drug release, corneal permeation, and pharmacokinetics in rabbit aqueous humor. METHODS Single factor investigation was carried out to optimize the formulation, taking viscosity and gelling capacity as evaluation indices. Using aqueous solution or eye drops as control, the in vitro release of the formulation was evaluated by dialysis membrane method. Then, the corneal permeation experiment of the optimum formulation was carried out with Franz diffusion cell. The pharmacokinetics of BDZL-ISG in rabbit aqueous humor was preliminarily studied by microdialysis. RESULTS Compared with the control group, the optimum formulation had shear thinning behavior and significant sustained release effect. There was no significant difference in the corneal permeation between the two groups. The RESULTS of pharmacokinetic study showed that ??_max (13.25 ??g??L^-1) and AUC_0-t of BZDL-ISG were 2.38 and 2.2 times higher than those of BDZL eye drops respectively, which suggested that the ocular bioavailability of BDZL was greatly enhanced by the optimum in situ gel formulation. CONCLUSION With significant sustained release effect, the ion-sensitive ophthalmic in situ gel will become a promising alterative formulation for bendazac lysine for treatment of cataracts.     

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??Topical ocular medication is commonly used for eye diseases treatment.In view of low bioavailability and poor efficacy of traditional ocular preparations,the development of novel ocular drug delivery systems has become a great challenge in pharmaceutics.In recent years, nano preparations have been widely used for ocular drug delivery systems. At present, several nanocarriers, such as polymeric micelles, nanoparticles, nanosuspension, liposomes, emulsion, and dendritic polymers have been developed for ocular drug delivery.There are some other new dosage forms, such as in-situ gelling systems, implants, contact lenses, and microneedles are also under continuous research. The aim of development of these new dosage forms is to improve the drugs' ocular bioavailability and therapeutic effects.In this paper,the development in these areas in recent years are reviewed in order to provide reference for the development of new ocular drug delivery systems.     

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??OBJECTIVE To examine the in vitro release profile and in vivo retention of estradiol vaginal thermosensitive gel (E2-VTG).METHODS E2-VTISG was prepared by cold dissolving method.The dynamic membrane dialysis method and HPLC-fluorometric method were used to determine the in vitro release characteristic of the estradiol vaginal thermosensitive gel.CRi Maestro was applied to evaluate the retention of E2-VTG in ICR mice with IR820 as the fluorescent marker. RESULTS Estradiol could be released slowly from the thermosensitive gel and the release profile was fitted with Higuchi equation. It was speculated that estradiol was mainly released through diffusion.NIR imaging and fluorescence quantitative analysis showed that thermosensitive gel could reside in vagina for at least 8 h. CONCLUSION Estradiol thermosensitive gel can prolong the drug residence time in vagina and sustain the drug release rate.     

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??OBJECTIVE To investigate the enhancing effect of borneol on the absorption of chlorogenic acid (CGA) with two different biological models and to evaluate the correlation of these two models. METHODS The in situ rat perfusion model was used to investigate the enhancing effect of borneol on the absorption of CGA. The in vivo pharmacokinetics study was carried out to evaluate the correlation of the two-compartment open model.RESULTS With the in situ rat perfusion model, the absorption rate constant (Ka) of CGA was 0.083 4 h^-1,which was up to 1.58-fold higher by borneol. The results of in vivo pharmacokinetics study in rats suggested that 0.04% borneol could increase the relative bioavailability by 116.02% and maximum plasma concentration increased slightly. The consistent result of these two different absorption models was provided (r??0.941). CONCLUSION Borneol could promote the oral absorption of CGA.
     

阴道用中药原位凝胶的研究进展

原位凝胶是一类以溶液状态给药后,能在用药部位立即发生相转变,由液态转化形成非化学交联半固体凝胶的制剂。其具有溶液和凝胶的双重优势,已成为药剂学研究的热点。传统的阴道给药剂型存在滞留时间短、生物利用度低等问题,近年来已有较多研究将新型原位凝胶应用于阴道给药,通过延长阴道内滞留时间来提高药物的生物利用度。中药原位凝胶有利于其药效的提升,通过参阅近年来国内外相关文献,从阴道用中药原位凝胶剂的特点、分类、制备和评价方法等方面进行综述,以期为阴道用中药原位凝胶剂的进一步研究与应用提供依据。     

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??OBJECTIVE To evaluate the effects of drug concentration and perfusion rate on the recoveries of self-made linear microdialysis probes for further ocular pharmacokinetic study. METHODS Brimonidine tartrate was selected as the model drug. The in vitro recovery was determined using positive dialysis and retrodialysis at different perfusion rates and drug concentrations. And the in vivo recovery was determined using retrodialysis method. RESULTS The microdialysis recoveries of brimonidine tartrate were inversely proportional to perfusion rate,while independent of drug concentration. The positive dialysis and retrodialysis recoveries in vitro were different at 1.0 ??L??min^-1, but no significant difference at 2.0 and 3.0 ??L??min^-1. The in vitro recoveries were greater than those in vivo. CONCLUSION The self-made microdialysis probe has stable recovery and can be used in ocular pharmacokinetic study of brimonidine tartrate.     

眼用制剂的前药及其药动学研究进展

前药是自身无活性,在体内经化学或酶代谢后释放出有药效活性的原药或代谢物的化合物。前药设计是一种改善眼用制剂不良性质,如水溶性差、生物利用度低、半衰期短和眼部刺激性的重要手段。眼用制剂的药动学主要研究眼对药物的吸收、分布、代谢和排泄的规律。笔者将按照结构修饰类型综述眼用前药的药动学研究进展,从而指导临床合理用药、减少不良反应、提高疗效。     

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??OBJECTIVE To study the pharmacokinetics of risperidone (RIS) nasal gel and its brain targeting effect and related mechanisms in rats. METHODS The concentrations of RIS in rat plasma and brain tissues were determined by HPLC method. The pharmacokinetics and relative bioavailability to oral RIS preparation of RIS nasal gel and the drug distribution in various brain tissues such as olfactory bulb (OB), olfactory tract (OT), cerebellum (CL) and cerebrum (CR) were investigated in rats. RESULTS The main pharmacokinetic parameters of RIS following nasal and oral administration such as t_max and ??_max were 5 and 20 min, 9.89 and 1.93 ??g??mL^-1, respectively. The relative bioavailability of nasally administered RIS was up to 4 730%. Furthermore, the AUC values of RIS nasal gel for different brain tissues such as OB, OT, CL and CR were found to be 45.3,9.9,1.5 and 1.1 folds of those of oral drug suspension, respectively. CONCLUSION The in vivo absorption rate and bioavailability of RIS following nasal administration are obviously increased and improved. Additionally, the significant brain targeting characteristics of the drug nasal gel is also confirmed.