Microparticles sustained delivery

U. B. Kompella, N. Bandi, and S. P. Ayalasomayajula. Subconjunctival nano- and microparticles sustain retinal delivery of budesonide, a corticosteroid capable of inhibiting VEGF expression. Invest Ophthalmol Vis Sci 44 1192-1201 (2003)... 

Cerchiara, T., Luppi, B., Chidichimo, G., Bigucci, F., and Zecchi, V. (2005), Chitosan and poly(methyl vynil ether-co-maleic anhydride) microparticles as nasal sustained delivery systems, Eur. J. Pharm. Biopharm., 61,195-200. 

In an earlier paper, we described the production and characterization of biodegradable microparticles containing tetracycline, which were designed for periodontal disease therapy. Microparticles were made by using different preparation procedures and different polyesters poly(L-lactide), poly(DL-lactide), and poly(DL-lactide-co-glycolide) 50 50. Selection of the appropriate preparation method and polyester enabled us to obtain biodegradable microparticles intended for sustained delivery of tetracycline to the periodontal pocket [23],... 

Esposito, E. et al., Biodegradable microparticles for sustained delivery of tetracycline to the periodontal pocket formulatory and drug release studies, J. Microencapsul., 14, 175, 1997. 

Xie, J., R.S. Tan, and C.-H. Wang. Biodegradable microparticles and fiber fabrics for sustained delivery of cisplatin to treat C6 glioma in vitro. Journal of Biomedical Materials Research Part A 85(4) (2008) 897-908. 

Shah S. Biodegradable microparticles for the sustained delivery of therapeutic drugs. EU patent... 

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. 

Subconjunctival injections of sustained-release matrix materials or microparticles have produced significant levels in the vitreous cavity. Although the kinetics of transscleral drug delivery to the retina and choroid are... 

Use of microparticle systems is not limited to the sustained or local delivery and has a wide range of applications. A limited number of examples are introduced below. 

Koushik K, Bandi N, Kompella UB. Respiratory delivery of a peptide drug degradation pathways, transport mechanisms, and sustained release large porous microparticles prepared using supercritical fluid technology. AAPS Pharm Sci 2002 4, (Abstract R6117). 

As for a formulation using another administration route, Leitner et al. developed a nasal delivery system of hGH [194] based on the thiomer polycarbophil-cysteine (PCP-Cys) in combination with the permeation mediator glutathione (GSH). Microparticles were prepared by dissolving PCP-Cys/GSH/hGH (7.5 1 1.5), PCP/ hGH (8.5 1.5), and mannitol/hGH (8.5 1.5) in demineralized water, followed by lyophilization and micronization. PCP-Cys/GSH/hGH and PCP/hGH microparticles showed a comparable size distribution (80% in the range of 4.8 to 23 pm) and swelled to almost four fold size in phosphate-buffered saline. Both formulations exhibited almost identical sustained drug release prohles. The intranasal administration of the PCP-Cys/GSH/hGH microparticulate formulation resulted in a relative bioavailability of 8.11%, which represents a three fold and a 3.3-fold improvement compared with that of PCP/hGH microparticles and mannitol/hGH powder, respectively. The nasal microparticulate formulation based on PCP-Cys/ GSH/hGH might represent a promising novel tool for the systemic delivery of hGH. 

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