Cyclodextrins release control

Hirayama, F., and Uekama, K. Cyclodextrin-based controlled drug release system. Adv. Drug Deliv. Rev. 36(1) 125-141, 1999. 

Y. Ikeda, K. Kimura, F. Hirayama, H. Arima, and K. Uekama, Controlled release of a water-soluble drug, captopril, by a combination of hydrophilic and hydrophobic cyclodextrin derivatives,/. Control Release, 66 (2-3), 271-280,2000. 

G. De Rosa, D. Larobina, M. Immacolata La Rotonda, P. Musto, F. Quagha, and F. Ungaro, How cyclodextrin incorporation affects the properties of protein-loaded PLGA-based microspheres The case of insuhn/hydroxypropyl-P-cyclodextrin system, /. Control Release,... 

Bary, A. R., Tucker, I. G., and Davies, N. M. 2001. An insight into how cyclodextrins increase the ocular bioavailability of poorly water-soluble compound3roceedings-28th International Symposium on Controlled Release of Bioactive Materials and 4th Consumer and Diversi ed Products Conference San Diego, CA, United States, June 23-27, 2001. 

Murthy, S.N., et al. 2004. Cyclodextrin enhanced transdermal delivery of piroxicam and carboxy-fluorescein by electroporation. J Control Release 99 393. 

Salem LB, Bosquillon C, Dailey LA et al (2009) Sparing methylation of beta]-cyclodextrin mitigates cytotoxicity and permeability induction in respiratory epithelial cell layers in vitro. J Control Release 136(2) 110—116... 

V. M. Rao, J. L. Haslam, and V. J. Stella. Controlled and complete release of a model poorly water-soluble drug, prednisolone, from hydroxypropyl methylcelluose matrix tablets using (SBE)7m-P-cyclodextrin as a solubilizing agent. J. Pharm. Sci. 90 807-816, 2001. 

A. Fetzner, L. Pfeuffer, and R. Schubert, Enzymatic degradation studies of (5-cyclodextrin with regard to the development of colonic specific release formulations, Proceed. Intern. Symp. Control. Rel. Bioact. Mater. 24 801-802 (1997). 

The ability of some components of nucleic acids, especially those with an adenine base, to form complex with 8-cyclodextrin, can also be readily used for chromatographic separations of various nucleotides and nucleosides (59). A substantial problem associated with application of cyclodextrin polymer gels, is that the accessibility of the cyclodextrin cavities on the surface and within the interior of the polymer particle is rather different. The rate of entrapment and release of solutes from the streaming liquid is obviously a diffusion controlled process. Consequently, a longer time is needed to reach an equilibrium within the particle than on its surface. The accessibility of the cyclodextrin rings will be more uniform, if the cyclodextrin is immobilized on the surface of non-complexing polymer particles (polyacrylamide, agarose (60,61) cellulose (62), and silica (63)). Therefore, a better separation (however lower capacity) is expected. 

Okimoto, K., Rajewski, R. A., and Stella, J. V. (1999), Release of testosterone from an osmotic pump tablet utilizing (SBE)7m-B-cyclodextrin as both a solubilizing and an osmotic pump agent, /. Controlled Release, 58, 29-38. 

Gao, H., Wang, Y. N. Fan, Y. G., and Ma, J. B. (2006), Conjugates of poly(DL-lactic acid) with ethylenediamino or diethylenetriamino bridged bis(P-cyclodextrin)s and their nanoparticles as protein delivery systems, / Controlled Release, 112,301-311. 

Memi oglu-Bilensoy, E., Vural, I., Renoir, J. M., Bochot, A., Duchene, D., and Hincal, A. A. (2005), Tamoxifen citrate loaded amphiphilic P-cyclodextrin nanoparticles In vitro characterization and cytotoxicity, J. Controlled Release, 104,489-496. 

Fig. 34 Example of mechanized mesoporous silica nanoparticles (MSNPs). SEM (a) and TEM (b) images show the structure and morphology of the MSNP platform [238]. (c) Structural formula of the a-cyclodextrin-based snap-top rotaxane that blocks the pores of an enzyme-cleavable mechanized MSNP. The stopper is connected to the stalk (dumbbell) by an ester or an amide bond [254]. (d) Release profile of rhodamine B from the snap-top MSNP. The addition of an esterase enzyme cleaves the ester bond, releasing the stopper, a-cyclodextrin, and cargo from the nanoparticles, which is monitored by the fluorescence intensity of rhodamine B. Controls employing an amide bond snap-top or deactivated enzyme do not release significant amounts of cargo...

The particles of cyclodextrin-grafted silicone are also the vehicles for the transport of the active substance to the site of its therapeutic action. In the case of anti-fnngal dosage form for topical administration action, penetration and slow release in the skin is searched for [21-23]. The stratum corneum top layer is made of cor-neocytes separated by a lipidic intercellular medium. Internal layers, epidermis and dermis are essentially aqueous media. The top layer is hydrophobic whereas the internal layers are hydrophilic. The penetration into the skin is controlled by the hydrophobic character of the particles. Hydrophobic materials easily penetrate and possibly accumulate in the stratum corneum. A slow release of the drug into the deep hydrophilic layers is possible from this medium. Silicone emulsions are often selected for cosmetic formulations because of the favorable spreading of silicone oils at the skin surface together with their low-irritancy properties. 

Masson, M. Loftsson, T. Masson, G. Stefansson, E. Cyclodextrins as permeation enhancers some theoretical evaluations and in vitro testing. J. Control Release 1999, 59, 107-118. 

Matsubara K, Irie T, Uekama K. Controlled release of the LHRH agonist buserelin acetate from injectable suspensions containing triacetylated cyclodextrins in an oil vehicle. J Control Release 1994 31 173-180. 

Sulfobutylether P-cyclodextrin can form noncovalent complexes with many types of compounds including small organic molecules, peptides, and proteins. It can also enhance their solubility and stability in water. The first application of sulfobutylether P-cyclodextrin was in injectable preparations it can also be used in oral solid and liquid dosage forms, and ophthalmic, inhalation, and intranasal formulations. Sulfobutylether P-cyclodextrin can function as an osmotic agent and/or a solubilizer for controlled-release delivery, and has antimicrobial preservative properties when present at sufficient concentrations. 

Sajeesh S, Bouchemal K, Marsaud V et al (2010) Cyclodextrin complexed insulin encapsulated hydrogel microparticles an oral delivery system for insulin. J Control Release 147(3) 377-384... 

Uekama, K., Horikawa, T., Horiuchi, Y, Hirayama, F. In vitro and in vivo evaluation of delayed-release behaviour of diltiazem from its O-carboxymethyl-O-ediyl-p-cyclodextrin complex. J. Control Release 1993, 25, 99-106. 

Horiuchi, Y, Abe, K., Hirayama, F., Uekama, K. Control of dieophyl-hne by p-cyclodextrin derivatives hybridizing of hydrophihc and ionizable p-cyclodextrin complexes. J. Control Release 1991, 15, 177-182. 

---