Drug delivery colon

In order to look at the probable duration of treatment with topical agents for colonic drug delivery, we have conducted studies with normal subjects and patients with left-sided colitis. The subjects and patients were dosed daily with indium-Ill-labeled amberlite resin and imaged throughout the day. On the fourth, the division of activity in the colon was 67% in the proximal half and 33% in the distal half day for the control subjects, whereas for the patients with colitis the distribution was 90 10. These data emphasize the problem of treating left-sided colitis effectively during active periods of disease. 

Macleod et al. [92] have studied the potential of pectin-chitosan-hydroxypropyl methylcellulose films for colonic drug delivery [92]. The results showed that in all cases the tablets were able to pass through the stomach and small intestine intact. The tablets started to break up once they were in the colon, due to degradation of the coat by colonic bacteria. 

Peeters, R., and Kinget, R., Film-forming polymers for colonic drug delivery. Synthesis and... 

Wakerly, Z., Fell, J.T., Attwood, D., and Parkins, D., Peetin/ethyl eellulose film-eoating formulations for colonic drug delivery, Pharm. Res., 13 1210-1212 (1996). Lorenzo-Lamosa, M.L., Remunan-Lopez, C., Vila-Jato, J.L., and Alonso, M.J., Design of microencapsulated chitosan microspheres for colonic drug delivery, J. Contr. Rel, 52 109-118 (1998). 

Krishniah, Y.S.R., Satyanaranaya, S., Rama Prasad, Y.V., and Narsimha Rao, S., Gamma scintigraphic studies on guar gum matrix tablets for colonic drug delivery in healthy human volunteers, J. Contr. Pel., 55 245-252 (1998). 

Shareef MA, Khar RK, Ahuja A, et al. Colonic drug delivery an updated review. AAPS PharmSti. 2003 5 E17. 

Obviously, satisfactory colonic absorption of the drug to be delivered is a sine qua non for the successful development of a colonic drug delivery system. However, situations exist when even reduced absorption from the large intestine (compared with the small intestine) would still justify colonic delivery, for instance in the case of a peptide drug that would otherwise be efficiently digested in the small intestine. 

A particular challenge for targeted colon drug delivery is the development of peroral application forms containing peptides and proteins, particularly low-... 

H. Yuasa, Y. Kimura, K. Hamamoto, and J. Watanabe, Evaluation of large intestine as an absorption site for colonic drug delivery, Proceed. Intern. Symp. Control. Rel. Bioact. Mater. 23 547-548 (1996). 

D. R. Friend, Glycosides in colonic drug delivery, Chapter 6 (D. R. Friend, ed.), Oral Colon-specific Drug Delivery, CRC Press, Boca Raton, 1992, pp. 153-187. 

Z. Wakerly, J. Fell, D. Attwood, and D. Parkins, Studies on amidated pectins as potential carriers in colonic drug delivery, J. Pharm. Pharmacol. 49 622-625 (1997). 

Figure 6.14 The Pulsincap colonic drug delivery device...

Rubinstein, A. (2005), Colonic drug delivery, Drug Discovery Today Technol.,2, 33-37. 

Basit, A., and Bloor, J. (2003), Perspectives on colonic drug delivery, Pharmatech, 185-190. 

Lorenzo-Lamosa ML, Remunan-Lopez C, Vila-Jato JL, and Alonso MJ. Design of microencapsulated chitosan microspheres for colonic drug delivery. J. Control. Rel. 1998 52 109-118. 

Spherical pellets containing 5% triamcinolone acet-onide were prepared by Villar-Lopez and coworkers byextrusion/spheronization after formulation with microcrystalline cellulose and/or a hydrophilic excipient such as lactose, sodium carboxymethylcellulose, or p-cyclodextrin. Their suitability for coating, with a view toward colonic drug delivery, was assessed in terms of their size, sphericity, and dissolution test... 

Wakerly, Z. Fell, J.T. Attwood, D. Parkins, D. Pectin/ ethyl cellulose film coating formulations for colonic drug delivery. Pharm. Res. 1996, 13, 1210-1212. 

Slew LF, Basit AW, Newton JM. The properties of amylose-ethyicellulose films cast from organic-based solvents as potential coatings for colonic drug delivery. Eur Pharm Sci 2000 11(2) 133-139. 

Adkin DA, Kenyon CJ, Lemer El, et al. The use of scintigraphy to provide proof of concept for novel polysaccharide preparations designed for colonic drug delivery. Pharm Res 1997 14(1) 103-107. 

Sinha VR, Mittal BR, Bhatani KK, Kumria R. Colonic drug delivery of 5-fluoracil an in vitro evaluation. Int J Pharm 2004 269(1) 101-108. 

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