Delivery efficiency

Delivery efficiency is low (only a fraction of drug content is delivered)... 

Recently, Choy et al. also reported that LDHs are an efficient drug reservoir for folate derivatives [187]. Folic acid derivatives, folinic acid and methotrexate (MTX), have been successfully hybridized with Mg/Al LDHs by ion-exchange reactions. Cellular uptake tests with the MTX-LDH hybrids were carried out in the fibroblast (human tendon) and osteosarcoma (SaOS-2) cell lines by in vitro assay. They found that the LDH not only plays a role as a biocompatible delivery matrix for drugs but also facilitates a significant increase in the delivery efficiency. 

LA/3A SA/3A Minimally effective inspiratory delivery efficiency as MDI either... 

Stewart, L.,Manvell, M.,Hillery, E., Etheridge, C.J., Cooper, R.G., Stark, Et. etal. (2001) Physico-chemical analysis of cationic hposome-DNA complexes (hpoplexes) with respect to in vitro and in vivo gene delivery efficiency. J. Chem. Soc. Perkin Trans., 2, 624-632. 

Elong, M.K., Wong, S.C., Farb, A., Mehlman, M.D., Virmani, R., Barry, J.J. et al. (1993) Feasibility and drug delivery efficiency of a new balloon angioplasty catheter capable of performing simultaneous local drug delivery. Coron. Artery. Dis., 4, 1023-1027. 

Lee C-C, Liu Y, Reineke TM (2008) General structure-activity relationship for poly(gly-coamidoamine)s the effect of amine density on cytotoxicity and DNA delivery efficiency. Bioconjug Chem 19(2) 428—440... 

What can be expected in the near and middle future for inhaled powder delivery There certainly will be some more new passive devices to reach the market and the patient, but it seems that a lot of purely mechanical design ideas have been implemented already in the newest generation of multiple-dose DPIs. Most important are audible and visible feedback features that help to improve delivery efficiency and patient compliance. Future improvements also seem possible in reducing dependency of the particle dispersion on actuation flow rate and internal device resistance. The next or over-next generation of multiple-dose devices also may incorporate lean, inexpensive, but rugged electronics... 

MDI delivery efficiency depends on the patient s inspiratory flow rate, breathing pattern and hand-mouth coordination. Increases in tidal volume and decreases in respiratory frequency enhance the peripheral deposition in the lung. Most patients need to be trained to use the MDI correctly, as up to 70% of patients fail to do so [26, 30]. 

Certain absorption sites, for example the alveolar region of the lungs, are not readily accessible and thus may require quite complex delivery devices to ensure the drug reaches the absorption site. Delivery efficiency to such sites may also therefore be low. In contrast, other sites, such as the skin, are highly accessible. 

Obviously the future costs given in Table 4-1 are speculative and were based on the committee s consensus views of what might be possible. They are to some extent optimistic. Table 4-1 also includes a column on overall efficiency from raw material to final product at the pump, which is interesting for showing how difficult it is to approach today s gasoline refining and delivery efficiencies. 

Stein, S. W., and Myrdal, P. B. (2006), The relative influence of atomization and evaporation on metered dose inhaler drug delivery efficiency, Aerosol Sci. Tech., 40,335-347. 

Selection of an optimal CPP for delivering a specific cargo into a particular cell type, especially in vivo, is not necessarily a trivial task. Until now there are relatively few studies devoted to the comparison of the cellular delivery efficiency of different CPPs and the correlation to their side effects such as cytotoxicity and membrane destabilizing properties. Comparative data of the delivery efficiency of CPPs in vivo are even more scarce. 

Additional factors that could influence the delivery efficiency and possible side effects of PNA-vector chimeras include the physical linkage between the PNA sequence and vector. Below we provide an overview of different conjugation strategies and provide a step-by-step protocol for disulfide bridge formation between PNA and carrier peptide. 

One difficulty associated with polymer-based gene therapy is that delivery efficiency is generally low, due to redirection of the polymer complexes to and enzymatic hydrolysis of the DNA in the lysosome, rather than release of DNA from the endosome (see Figure 2). A strategy to circumvent this is to include polymers that disrupt the endosomal membrane. This is achieved if they are active i.e. protonated) at pH 6.5 or below, but inactive (deprotonated) at pH 7.4, since the endosomal pH is around one unit lower than the cytoplasm. Hoffman, Tirrell and co-workers have developed synthetic polymers such as poly(alkyl acrylic acid)s and poly(acrylate-co-acrylic acid)s that show en-... 

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