Drug delivery microparticles

Cosmetics Sunscreen, foundation excipient, drug delivery Microparticles + Nanopaiticles +... 

A large variety of drug delivery systems are described in the literature, such as liposomes (Torchilin, 2006), micro and nanoparticles (Kumar, 2000), polymeric micelles (Torchilin, 2006), nanocrystals (Muller et al., 2011), among others. Microparticles are usually classified as microcapsules or microspheres (Figure 8). Microspheres are matrix spherical microparticles where the drug may be located on the surface or dissolved into the matrix. Microcapsules are characterized as spherical particles more than Ipm containing a core substance (aqueous or lipid), normally lipid, and are used to deliver poor soluble molecules... 

Kumar, M. (2000). Nano and microparticles as controlled drug delivery devices. Journal of Pharmacy and Pharmaceutical Sciences, Vol. 3, 2, (May-August 2000), pp. (234-258), ISSN 1482-1826... 

Torchilin, V. P. (2006). Multifunctional nanocarriers. Advanced Drug Delivery Reviews, Vol. 58, 14, (December 2006), pp. (1532-1555), ISSN 0169-409X Tran, V. T., Benoit, J. P. Venier-Julienne, M. C. (2011). Why and how to prepare biodegradable, monodispersed, polymeric microparticles in the field of pharmacy International Journal of Pharmaceutics, Vol. 407,1-2, (December 2011), pp. (1-11), ISSN 0378-5173... 

W Im-Emsap, GA Brazeau, JW Simpkins, R Bodmeier. Sustained drug delivery of 17-/1 estradiol from injectable biodegradble in situ forming microparticles (ISM) system. AAPS PharmSci Supplement 2(4), AAPS Annual Meeting Abstracts, 2000. 

Nanoparticles show great promise as devices for the controlled release of drugs, provided that the choice of material for nanoparticle formation is made with the appropriate considerations of the drug cargo, administration route, and the desired site of action. The use of nano- and microparticles as controlled drug-delivery devices has recently been extensively reviewed [97]. 

As above reported, among microparticles, CLS have been proposed as a new type of fat-based encapsulation system developed for drug delivery of bioactive compounds. 

Fig. 14. Targeting of microparticles (e.g., bubbles and emulsion droplets) destined for molecular imaging and drug delivery Schematic simultaneous binding to a microparticle of a targeting device (antigen-specific ligands), of stealth-providing elements (e.g., PEG strands), and of drugs and markers (e.g., a Gd + chelate for MRI contrast enhancement).

The amount of investigational work on the subject of formulation also needs further review and amplification. Basic formulation studies have suggested that proteins could be used to form drug delivery systems (e.g., microparticles) the interactions of proteins with phospholipids is of sufficient interest to justify a short chapter. 

The use of albumin microparticles as a drug delivery system was first suggested by Kramer (1974) and several methods for their production were subsequently developed (Gupta and Haung 1989). Most methods involved the application of emulsification methodology and factors involved in this process have been evaluated by a number of authors. However, studies of the in vitro disintegration process of protein microspheres, induced by the presence of protease enzymes in the environment, are limited (El-Samaligy and Rohdewald 1983). 

A composition based on diketopiperazine derivatives (3,6-bis (N-fumaryl-N-(n-butyl) amino-2, 5-diketopiperazine) has been investigated as a pulmonary drug delivery system, termed Technospheres (Pharmaceutical Discovery Corp., Elmsford, NY) (Pohl et al. 2000 Steiner et al. 2002). The diketopiperazine derivatives self-assemble into microparticles at low pH with a mean diameter of approximately 2 pm. During self-assembly, diketopiperazine derivatives microencapsulate peptides present in the solution. Insulin incorporated in diketopiperazine derivatives (TI) was administered to five healthy humans by the use of a capsule-based inhaler with a passive powder deagglomeration mechanism. Relative and absolute bioavailability of TI in the first 3 hours (0-180 min) were 26 12% and 15 5%, and for 6 hours (0-360 min) 16 8% and 16 6%, respectively (Steiner et al. 2002). The time to peak action for glucose infusion rates was shorter with both IV (14 6 min) injection and inhalation (39 36 min), as compared to SC administration (163 25 min). This rapid absorption of insulin would be beneficial for diabetic patients who need to rapidly affect their glucose levels. 

As reported later in Chapter 9.9 of this book, active-ingredient-containing polymeric micro-particles are widely used in technological and medical applications. For example, these particles are suitable as drug-delivery devices and can control the pharmaceutical release-rate over time. The particle size is absolutely important when dealing with drug-delivery devices. Very small particles can be inhaled, while larger ones can be injected into the blood stream. Therefore, it is important to control the microparticle size in the production. 

Clark, M.A., B.H. Hirst, and M.A. Jepson. 2000. Lectin-mediated mucosal delivery of drugs and microparticles. Adv Drug Deliv Rev 43 207. 

Cuna, M., Alonso, M. J., and Torres, D. Preparation and in vivo evaluation of mucoadhesive microparticles containing amoxycillin-resin complexes for drug delivery to the gastric mucosa. Eur. J. Pharm. Biopharm. 51(3) 199-205, 2001. 

Haghpanah, M., Marriott, C., and Martin, G. P. Drug delivery to the lung using albumin microparticles. J. Pharm. Pharmacol. 46(suppl) 1075, 1994. 

Gradus-Pizlo I, Wilensky RL, March KL, et al. Local delivery of biodegradable microparticles containing colchicine or a colchicine analogue effects on restenosis and implications for catheter-based drug delivery. J Am Coll Cardiol 1995 26(6) 1549-1557. 

Key Words shRNA RNAi Biodegradable polymer Natural polymer Synthetic polymer Non-viral gene delivery Drug delivery Nanoparticle Microparticle Tumor targeting. 

Masters and Domb [250] reported on an injectable drug delivery system that uses liposomes [251] to release the local anesthetic, bupivacaine, from a liposomal matrix that is both biodegradable and biocompatible to produce SLAB. Bupivacaine due to its minimum vasodilating properties was preferred to other local anesthetics (e.g., lidocaine) allowing the released drug to remain at the site of injection longer [252]. Lipospheres are an aqueous microdispersion of water insoluble, spherical microparticles (0.2 to 100 pm in diameter), each consisting... 

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