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Chitosan Complex (chitosan + complex)
Selected AbstractsOptimizing preparation of NaCS,chitosan complex to form a potential material for the colon-specific drug delivery systemJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Ming-Jun Wang Abstract A novel polyelectrolyte complex (PEC) formed by sodium cellulose sulfate (NaCS) and chitosan was prepared as a candidate material for colon-specific drug delivery system. It was found in experiments that the properties of two raw materials and the process parameters, such as the degree of substitution (DS) and concentration of NaCS, the viscosity and concentration of chitosan, were very important factors on the properties of the final product,NaCS,chitosan-PEC. The preparation of NaCS,chitosan complex was optimized by using response surface methodology to evaluate the effects of these parameters on the degradation properties of NaCS,chitosan in the simulated colonic fluid (SCF). The DS of NaCS was in the range from 0.2 to 0.6, the concentration of NaCS from 2 to 4% (w/v), the viscosity of chitosan from 50 to 550 mPa s, and the concentration of chitosan from 0.5 to 1.5% (w/v). A mathematical model was developed to describe the effect of these parameters and their interactions on the degradation of NaCS,chitosan complex. The optimum operation conditions for preparing NaCS,chitosan complex were determined to DS of NaCS of 0.2, the concentration of NaCS of 4.0% (w/v), chitosan viscosity of 327 mPa s, and the concentration of chitosan 0.5% (w/v), respectively. Validation of experiments with 5 confirmatory runs indicated the high degree of prognostic ability of response surface methodology. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Effect of Iron(III) Chitosan Intake on the Reduction of Serum Phosphorus in RatsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 7 2000JOSEPH BAXTER Because of the widespread use of aluminium- and calcium-containing phosphate binders for the control of hyperphosphataemia in patients with end-stage renal failure, an iron(III) chitosan complex was synthesised and fed to rats to measure its effect on serum phosphorus and calcium, intestinal phosphate binding and phosphate absorption. Thirty-six Wistar rats were randomly selected and distributed into a baseline group (n = 6), a control group (n = 8 (days 0,15), n = 8 (days 16,30)) and a treatment group (n = 8 (days 0,15), n = 8 (days 16,30)). The control groups ingested AIN-76 diet mix with a 1% w/w fibre content; however, the treatment groups had the fibre content completely substituted with iron(III) chitosan. The mean weights of the treated rats were slightly lower from 15 days (not significant); but overall, rat growth was not stunted in the treatment groups. The serum phosphorus levels of the treated group (n = 8) were significantly reduced after 15 days (P = 0.004; control: 5.7 ± 0.9 mg dL,1; treatment: 4.4±0.5 mg dL,1; 95% CI of difference: 0.5,2.2) and 30 days (P = 0.002; control: 5.5 ± 0.9 mg dL,1; treatment = 4.1 ± 0.6 mg dL,1; 95% CI of difference: 0.6,2.3) as compared with the respective control group. The serum calcium-phosphorus product was 62.0 ± 12.1 mg2 dL,2 for the control and 45.1 ± 6.6 mg2 dL,2 for the treatment group after 30 days (P = 0.004). The serum iron concentration of the treatment group did not differ from the baseline value after 15 and 30 days, but the treatment group was significantly higher than the control group (P < 0.05) after 30 days. The faeces phosphorus levels (mg day,1) were higher (P < 0.01) and its iron content was much higher (P < 0.01) for the treated group. The urine phosphorus (mg kg,1) was not significantly reduced for the treated group, but the mean was consistently less. The kidney and liver weights of both groups were similar, but the phosphorus content of the kidney (mg (g kidney),1) was higher for the treated group after 30 days (P = 0.041; control, 4.2 ± 1.2 mg g,1 vs treatment, 5.6 ± 1.4 mg g,1. Because iron(III) chitosan had a high phosphorus-binding capacity of 308 (mg P) per gram of Fe3+ for both the in-vitro (pH 7.5) and in-vivo studies, which is greater than nearly all commonly used phosphate binders, and a small net phosphorus absorption difference of 3.7 mg day,1, it is an efficient phosphate binder for lowering serum phosphate levels without increasing serum calcium levels. [source] Chitosan-based Polyelectrolyte Complexes Soluble in Enzyme-friendly pH RangeMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 4 2010Vladimir A. Izumrudov Abstract By studying chitosan interactions with poly(styrene sulfonate) anions, a procedure that yields chitosan-based non-stoichiometric polyelectrolyte complexes soluble in neutral media has been developed. The elaborated strategy of the complex formation depended on the peculiar order of mixing the polyelectrolyte solutions, which served as a remedy for kinetic hindrances. The kinetic restrictions inevitably occurred on direct mixing of the components in slightly acidic and neutral media, due to the significant contribution of hydrogen bonds in stabilization of the intermediate insoluble products. The approach developed opens up a new avenue of attack on the problem of preparing water soluble biocompatible and biodegradable chitosan complexes that are suitable for use at physiological pH and ionic strength. [source] | ||||||||||