Chitosan-coated formulation

Calvo, VilaJato, and Alonso studied chitosan-and poly-L-Lysine (PLL)-coated poly-e-Caprolactone (PECL) nanocapsules for ocular application. In comparison with commercial eyedrops, the systems investigated (uncoated, PLL-coated, and chitosan-coated nanocapsules) significantly increased the concentrations of indomethacin in the cornea and aqueous humor of rabbit eyes. The chitosan-coated formulation doubled the ocular bioavailability of indomethacin over the uncoated particles, whereas the PLL coating was ineffective. The authors concluded that the specific nature of chitosan was responsible for the enhanced indomethacin uptake and not the positive surface charge. Both the PLL- and chitosan-coated nanocapsules displayed good ocular tolerance. ... 

In order to observe the behavior of chitosan-coated liposomes more precisely, chitosan was labeled with fluorescein isothiocyanate (FITC) via chemical reaction at the isothiocyanate group of FITC and the primary amino group of chitosan the liposomes (Lips) were marked by incorporation of Dil into the liposomal formulation. FITC-labeled chitosan (FITC-CS), non-coated liposomes, and FITC-labeled chitosan-coated liposomes (FITC-CS-Lips) were intragastrically administered into male Wistar rats, and then the behavior of the molecules was visualized by CLSM (Thongborisute et al. 2006a). The results demonstrated that the chitosan molecules themselves, as well as the liposomes, could penetrate across the intestinal mucosa. Moreover, the CLSM images demonstrated a lack of separation of the chitosan molecules from the surface of the liposomes after the administration of chitosan-coated liposomes. 

Pectin has been used in film-coating formulations containing chitosan and hydroxypropylmethyl cellulose in the investigation of the biphasic drug-release properties of film-coated paracetamol tablets, both in vitro and in vivo It has been shown that chitosan acts as a crosslinking agent for concentrated pectin solutions. 

Nafee N, Taetz S, Schneider M, Schaefer UF, Lehr CM. Chitosan-coated PLGA nanoparticles for DNA/RNA delivery effect of the formulation parameters on complexation and transfection of antisense oligonucleotides. Nanomed Nanotech Biol Med. 2007 3(3) 173-83. 

Polymeric nanocapsules in sunscreen formulations have been investigated as to the effect on in vitro skin penetration of benzophenone-3. Benzophenone-3 loaded nanocapsules were prepared by the interfacial deposition poly(e-caprolactone) and coated using a chitosan solution. The nanoparticles were characterized and incorporated in hydrogels. Penetration profiles showed a higher amount of benzophenone-3 remained on the skin surface and a lower amount was found in the receptor compartment after the application of the formulation containing chitosan-coated nanocapsules compared to a formulation containing its free form (162). 

Biruss B, Valenta C (2006) Skin permeation of different steroid hormones from polymeric coated liposomal formulations. Eur J Pharm Biopharm 62 210-219 Brochard G, Luessen HL, Verhoef JC, Lehr CM, de Boer AG, Junginger HE (1996) The potential of mucoadhesive polymers in enhancing intestinal peptide drug absorption III Effects of chitosan-glutamate and carbomer on epithelial tight junctions in vitro. J Control Rel 39 131-138... 

Fig. 10.13 Profiles of plasma calcium levels after intragastric administration of submicronsized liposomes, ssLip, and ssCS-Lip containing calcitonin (taken from Takeuchi et al. 2005a) The measured mean particle sizes of ssLip and ssCS-Lip were 196.4 and 473.4 nm, respectively. The formulation of liposomes was DSPC DCP cholesterol = 8 2 1. The concentration of chitosan for coating was 0.3%. p<0.05, p<0.01, p<0.001 significantly different from the level for calcitonin solution tp<0.05, t1p<0.0l significantly different from the level for ssLip (n=3 in each case).

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