Delivery system, schematic

FIGURE 49.11 Ozurdex delivery system schematic. (From Weber, D. et al., Methods and Apparatus for Delivery of Ocular Implants, U.S.P.A.T. Organization, Allergan, Inc., p. 20, 2005.)... 

A schematic diagram of a chromatograph for SFC is shown in Figure 6.10. In general, the instrument components are a hybrid of components developed for gas and liquid chromatography that have been subsequently modified for use with supercritical fluids. Thus, the. fluid delivery system is a pump modified for pressure control and the injection system a rotary valve similar to components used in liquid chromatography. The column oven and... 

Liposomes have been, and continue to be, of considerable interest in drug-delivery systems. A schematic diagram of their production is shown in Fig. 10. Liposomes are normally composed of phospholipids that spontaneously form multilamellar, concentric, bilayer vesicles, with layers of aqueous media separating the lipid layers. These systems, commonly referred to as multilamellar vesicles (MLVs), have diameters in the range of 15 pm. Sonication of MLVs... 

Fig. 8 Schematic representation of dihydropyridine-pyridinium redox delivery system. (From Ref. 66)...

Figure 1 Schematic illustration of an ideal stimuli-modulated polymeric drug delivery system.

Other surface-active compounds self-assemble into bilayer structures (schematically illustrated in Fig. 10b), which normally spherilize into structures termed vesicles. When vesicles are formed from phospholipids, the term liposome is used to identify the structures, which also provide useful drug delivery systems [71]. Solutes may be dispersed into the lipid bilayer or into the aqueous interior, to be subsequently delivered through a variety of mechanisms. Liposomes have shown particular promise in their ability to act as modifiers for sustained or controlled release. 

Figure 1 is a schematic representation of the wet oxidation micro-pilot plant. The system consists of three sections, an electrically heated oxidation vessel, a high pressure solvent delivery system, and a water cooled depressurization and collection chamber. A more detailed description of the pilot plant can be found in previous publications (3,4). 

FIGURE 10.3 Schematic presentation of lipid based drug delivery systems. Micelles (right) are composed of a solid lipid core with the polar heads exposed to the aqueous environment. Liposomes (left) are particles with a hpid bilayer surrounding an aqueous core. Drug can be encapsulated in the hydrophobic regions of the lipid particle, in the aqueous environment of the liposome, or adsorbed to the surface of the lipid particle. 

FIGURE 22.14 Schematic illustration of Spherazole CR bioadhesive drug delivery system (a cross-sectional view). 

Figure 7.1 Schematic diagram of elementary osmotic delivery system.

The relationship between the concentration of drug and the disease state is illustrated schematically in Fig. 13.2. Because of the feedback mechanism, the programmable delivery systems for drug delivery can be thought of as an artificial imitation of healthy functioning. 

A hot water dynamic extraction device was constructed using the solubilization apparatus of Miller and Hawthorne (10) as a model and was used for pressurized extraction of milk thistle seed meal. Figure 2 shows a schematic diagram of the apparatus. Water, the extraction solvent, was pressurized and pumped using a Bio-Rad 2800 HPLC solvent delivery system (Hercules, C A) to an extraction cell housed in the oven of a Hewlett-Packard 5890 gas chromatography (GC) oven (Wilmington, DE). Before... 

In the early 1970s, the ALZA Corporation began its search for polymers suitable for erodible drug delivery systems. The ideal polymer was identified as one undergoing surface erosion in vivo and degrading to non-toxic, low molecular weight products at a rate that could be manipulated over a broad time span. To meet these criteria, a novel family of hydrolyzable polymers was developed, the poly(orthoesters), POEs [285]. The general structure is schematically shown in... 

Discrete models of release behavior. A schematic cross-section of a drug delivery system is shown in Figure 1 we hypothesize that release of drug occurs as follows. Prior to release, solid particles of the drug are dispersed in a continuous polymer phase. Since the depth of the device is typically 1 mm and each particle is... 

Figure 1 Schematic cross-section of a drug delivery system. A circular slab, cut in half in the plane parallel to release, is shown in the background. The exposed internal face is blown up in the foreground, revealing discrete particles of solid molecule dispersed in a continuous polymer phase. 

Figure 1. Schematic representation of insulin delivery systems.

Figure 8.3 Schematic diagrams of the three main categories of transdermal delivery system. It should be noted that these representations of the patches greatly exaggerate their real thicknesses, which are in fact similar to that of a normal Band-Aid...

FIGURE 8 Schematic for design of multifunctional drug delivery system (DDS) that includes pH-cleavable PEG-Hz-PE (a), temporarily shielded biotin or TATp (b), and monoclonal antibody (c) attached to surface of DDS via pH-noncleavable spacer. (Reprinted with permission from ref. 183. Copyright 2006 by the Americam Chemical Society.)... 

Nucleic acid delivery was also studies by Park et al. using CD-based nanoparticles prepared from P-CD-modified poly(ethylenimine) (CD-PEI).The inclusion-forming capability of P-CD was used in order to immobilize the nanoparticles on solid surfaces (adamantine-modified self-assembled monolayers). CD-PEI nanoparticles were proposed as delivery systems onto solid surfaces to attain specific and high affinity loading. The interaction is schematized in Figure 4 [44],... 

An HPLC system, shown schematically in Figure 2.1, consists of a solvent reservoir, which contains the eluent or mobile phse a pump, often called a solvent delivery system an injector through which the sample is introduced into the system without a drop in pressure or change in flow rate the analytical column, which is usually stainless steel and contains the solid packing or stationary phase and a suitable detector to monitor the eluent. 

Fig. 8 Generalized schematic diagram of a liquid delivery system.

Figure 1 Schematic representation of the basis of anodal and cathodal iontophoretic drug delivery systems.

Fig. 22 (A) Schematic illustration of Valrelease tablet, a swelling-activated drug-delivery system, and the hydration-induced formation of colloid gel barrier. (B) Comparison in the gastric residence profile between Valrelease with the conventional Valium capsule. (From Ref. l)...

Fig. 23 Schematic illustration of a pH-activated drug-delivery system and the pH-dependent formation of micro-porous membrane in the intestinal tract.

Fig. 7 A schematic representation of the unification of delivery systems to optimize therapeutic outcome with MoAbs (A) exposed target antigens (B) initial treatment with bridge molecules and (C) specific binding of unified carrier systems. (Adapted in part from Ref. l)...

Fig. 2 Schematic demonstration of different routes of drug release and cellular uptake. After a drug delivery system is administered, different events occur. Route a drug A is released during circulation and is taken up by both normal cells and tumor cells. Route b drug B is transported to the tumor interstitum and released extracellularly at the tumor site, and mainly taken up by tumor cells. Route c drug C is endocytosed with its carrier and released in the endosomes or lysosomes.

Fig. 5 Schematic feature of liposomal drug delivery systems (A) a sterically stabilized liposome, (B) a tumor targeted liposome or immunoliposome.

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