In Vitro Release and Diffusion Studies of Promethazine Hydrochloride from Polymeric Dermatological Bases Using Cellulose Membrane and Hairless Mouse Skin

The study was designed to investigate the feasibility of developing a transdermal drug dosage form of promethazine hydrochloride (PMH). The in vitro release and diffusion characteristics of PMH from various dermatological polymeric bases were studied using cellulose membrane and hairless mouse skin as the diffusion barriers. These included polyethylene glycol (PEG), hydroxypropyl methylcellulose (HPMC), cross-linked microcrystalline cellulose, and carboxyl methyl cellulose sodium (Avicel® CL-611), and a modified hydrophilic ointment USP. In addition, the effects of several additive ingredients known to enhance the drug release from topical formulations were evaluated. The general rank order for the drug release from these formulations using cellulose membrane was observed to be PEG > HMPC > Avicel CL-611 > hydrophilic ointment base. The inclusion of the additives had little or no effect on the drug diffusion from these bases, except for the hydrophilic ointment formulation containing 15% ethanol, which provided a significant increase in the drug release. However, when these formulations were studied for drug diffusion through the hairless mouse skin, the Avicel CL-611 base containing 15% ethanol exhibited the optimum drug release. The data also revealed that this formulation gave the highest steady-state flux, diffusion, and permeability coefficient values and correlated well with the amount of drug release.     

NTO·（3，5-DATr）含能离子盐和NTO/IMZ含能共晶的制备、晶体结构及性能

为改善钝感炸药3?硝基?1,2,4?三唑?5?酮(NTO)的酸性,将NTO分别与3,5?二氨基?1,2,4?三唑(3,5?DATr)、咪唑(IMZ)反应,制备得到了NTO·(3,5?DATr)含能离子盐(Ⅰ)和NTO/IMZ含能共晶(Ⅱ)。通过溶剂挥发法培养得到了单晶,利用X?射线单晶衍射仪确定了其晶体结构。晶体Ⅰ属于单斜晶系,空间群为P21/c,Mr=229.19,晶胞参数a=3.5687(7)?,b=17.245(3)?,c=14.655(3)?,β=93.79(3),V=899.9(3)?³,Z=4,D_c=1.692 g·cm^-3;晶体Ⅱ属于正交晶系,空间群为Pbcn,Mr=207.17,晶胞参数a=16.9398(16)?,b=5.6802(5)?,c=17.9111(19)?,V=1723.4(3)?³,Z=4,D_c=1.597 g·cm^-3。采用差示扫描量热法(DSC)和热失重法(TG)研究了其热分解行为,结果表明二者均具有良好的热稳定性。运用Gaussian 09程序对化合物结构进行优化并计算其生成焓,用EXPLO 5软件对二者的爆速和爆压进行了评估(Ⅰ:D=7662.3 m·s^-1,p=21.0 GPa;Ⅱ:D=6490.2 m·s^-1,p=14.6 GPa)。采用BAM方法测试了其机械感度,结果表明,二者均对撞击和摩擦钝感(IS>40 J,FS>360 N)。利用pH计测试了化合物标样的pH值,在0.01 mol·L^-1的标准溶液中NTO,Ⅰ和Ⅱ的pH值分别为2.92(22.8℃),4.10(22.7℃),4.98(22.8℃),表明盐和共晶的形成在一定程度上改善了NTO的酸性。     

CL-20/FOX-7共晶的分子动力学模拟

依据共晶形成的氢键规则,搭建了7种CL-20/1,1-二氨基-2,2-二硝基乙烯(FOX-7)共晶模型;采用分子动力学(MD)模拟研究了CL-20/FOX-7共晶形成的可能性;通过径向分布函数(RDF)考察了共晶模型内分子的相互作用力;采用X-射线粉末衍射(XRD)模拟分析了共晶模型与纯组分间衍射峰的区别。结果表明,FOX-7和CL-20分子间存在较强的氢键和范德华力,7种共晶模型的结合能大小顺序为:Eb(1 0 1)Eb(1 1-1)E_b(随机晶面)E_b(0 1 1)E_b(0 0 2)E_b(1 1 0)E_b(1 0-1);7种共晶模型的分子间作用力以FOX-7取代CL-20(1 0 1)、(11-1)晶面较强;7种共晶模型的XRD衍射峰相较纯组分CL-20或FOX-7区别较大。据此推测在制备CL-20/FOX-7共晶过程中,FOX-7取代CL-20(1 0 1)晶面的共晶模型易于形成。     

Supramolecular Interactions between C60 and a Zirconium Bisporphyrinate Double-decker Complex

Supramolecular interactions between C₆₀ and a zirconium bisporphyrinate double-decker complex were investigated in their co-crystal and solution. In the co-crystal, concave-convex interaction between C₆₀ and the complex plays the role for their association, while another type of C₆₀/porphyrin interaction together with C₆₀/C₆₀ interaction coexists. ¹³C NMR spectroscopy on mixtures of C₆₀ with the zirconium double-decker complex or the porphyrin ligand of that complex suggests that the affinity of the double-decker complex toward C₆₀ is higher than that of the corresponding ligand.     

Hot-melt extrusion – basic principles and pharmaceutical applications

Originally adapted from the plastics industry, the use of hot-melt extrusion has gained favor in drug delivery applications both in academia and the pharmaceutical industry. Several commercial products made by hot-melt extrusion have been approved by the FDA, demonstrating its commercial feasibility for pharmaceutical processing. A significant number of research articles have reported on advances made regarding the pharmaceutical applications of the hot-melt extrusion processing; however, only limited articles have been focused on general principles regarding formulation and process development. This review provides an in-depth analysis and discussion of the formulation and processing aspects of hot-melt extrusion. The impact of physicochemical properties of drug substances and excipients on formulation development using a hot-melt extrusion process is discussed from a material science point of view. Hot-melt extrusion process development, scale-up, and the interplay of formulation and process attributes are also discussed. Finally, recent applications of hot-melt extrusion to a variety of dosage forms and drug substances have also been addressed.     

In vivo brain microdialysis as a formulation-screening tool for a poorly soluble centrally acting drug

Objective: Efficacy of a formulation of a poorly soluble centrally acting drug was evaluated by measuring dopamine responses using in vivo brain microdialysis.

Methods: Co-crystals (1:1) of carbamazepine and nicotinamide (CBZ–NCT) were complexed with cyclodextrins (γ-CDs) using supercritical fluid processing. Phase solubility and intrinsic dissolution were studied. Pharmacodynamic studies were performed on rats divided into three groups getting either CBZ–NCT in CD (20?mg/kg CBZ), pure CBZ solution or vehicle. A guide cannula was implanted to attach the microdialysis probe. Dialysate samples were analyzed for dopamine levels, which were compared between groups.

Results: The optimized CBZ formulation (5% w/w in γ-CD) with solubility – 10?mg/mL showed stepwise increase in dopamine response (maximum 250% of baseline) compared to neat CBZ or vehicle (p?Conclusion: Hence, brain microdialysis was successfully used to evaluate a dissolution rate enhancing formulation.     

HMX/FOX-7共晶炸药分子动力学模拟

基于环四甲撑四硝胺(HMX)主要生长面和共晶形成氢键规则,搭建6种HMX/1基于环四甲撑四硝胺(HMX)主要生长面和共晶形成氢键规则,搭建6种HMX/11-二氨基22-二硝基乙烯(FOX-7)共晶模型。采用分子动力学(MD)模拟研究HMX/FOX-7共晶炸药形成的可能性。MD模拟过程中键长、键角、二面角发生严重扭曲。径向分布函数（RDF）考察HMX中氧原子和FOX-7中氢原子或HMX中氢原子和FOX-7中氧原子间的作用力。发现HMX和FOX-7分子间存在较强氢键和范德华力作用。根据最终HMX/FOX-7结构模型,进行结合能和X-射线粉末衍射（XRD）图谱计算。结果表明：6种共晶模型的结合能大小顺序为：E_b(0 2 0)>E_b(1 0 0)>E_b(随机)>E_b(111 )>E_b(102 )>E_b(0 11). 6种共晶模型的XRD衍射峰与纯组分HMX或FOX-7有很大区别。基于晶体生长形貌,结合能和径向分布函数的研究,FOX-7取代HMX（111 ）晶面的共晶模型易于形成。     

土豆泠冻干燥工艺的试验研究

本文对土豆冷冻干燥过程进行了深入研究,测得了土豆的共晶点和共熔点,对土豆的预处理工艺进行了试验研究,通过对土豆冻干试验因素的分析,得到了土豆的最佳冷冻干燥工艺.