Polysaccharides as potential antioxidative compounds for extended-release matrix tablets.

The objective of this study was to identify polysaccharides with antioxidant properties for use as potential antioxidative compounds for extended-release matrix tablets. The antioxidant properties of five different polysaccharides, high molecular weight alginate (H-ALG), low molecular weight alginate (L-ALG), high molecular weight chitosan (H-chitosan), low molecular weight chitosan (L-chitosan), and pectic acid (PA) were examined using N-centered radicals from 1,1\u27-diphenyl-2-picrylhydrazyl (DPPH) and 2,2\u27-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and reducing power, based on their ability to reduce Cu(2+). L-chitosan and PA had acceptable scavenging abilities and were good radical scavengers, with good reducing power, but the H-chitosan and alginate derivatives were much less effective. The results suggest that L-chitosan and PA could be useful in combating oxidative stress. A PA and L-chitosan interpolymer complex (IPC) tablet was prepared and evaluated as an extended-release tablet matrix using theophylline (TPH) as a model drug. The release of TPH from the matrix tablet (TPH/PA/L-chitosan=200 mg:150 mg:50 mg) was slower than that from PA only (TPH/PA/chitosans=200 mg:200 mg:0 mg) or L-chitosan only (TPH/PA/L-chitosan=200 mg:0 mg:200 mg) tablet. Turbidity measurements also indicated the optimum complexation ratio for IPC between PA/L-chitosan to be 1/3, indicating an acceptable relationship between the turbidity of the complex and the release ratio of TPH. These results suggest that an L-chitosan/PA complex would be potentially useful in an extended-release IPC tablet with high antioxidant activity.The objective of this study was to identify polysaccharides with antioxidant properties for use as potential antioxidative compounds for extended-release matrix tablets. The antioxidant properties of five different polysaccharides, high molecular weight alginate (H-ALG), low molecular weight alginate (L-ALG), high molecular weight chitosan (H-chitosan), low molecular weight chitosan (L-chitosan), and pectic acid (PA) were examined using N-centered radicals from 1,1\u27-diphenyl-2-picrylhydrazyl (DPPH) and 2,2\u27-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and reducing power, based on their ability to reduce Cu(2+). L-chitosan and PA had acceptable scavenging abilities and were good radical scavengers, with good reducing power, but the H-chitosan and alginate derivatives were much less effective. The results suggest that L-chitosan and PA could be useful in combating oxidative stress. A PA and L-chitosan interpolymer complex (IPC) tablet was prepared and evaluated as an extended-release tablet matrix using theophylline (TPH) as a model drug. The release of TPH from the matrix tablet (TPH/PA/L-chitosan=200 mg:150 mg:50 mg) was slower than that from PA only (TPH/PA/chitosans=200 mg:200 mg:0 mg) or L-chitosan only (TPH/PA/L-chitosan=200 mg:0 mg:200 mg) tablet. Turbidity measurements also indicated the optimum complexation ratio for IPC between PA/L-chitosan to be 1/3, indicating an acceptable relationship between the turbidity of the complex and the release ratio of TPH. These results suggest that an L-chitosan/PA complex would be potentially useful in an extended-release IPC tablet with high antioxidant activity

Useful Extend-release Chitosan Tablets with High Antioxidant Activity.

The antioxidant properties of different low molecular weight (LMW) chitosans (CS1; 22 kDa, CS2; 38 kDa, CS3; 52 kDa, CS4; 81 kDa) were examined for possible use in extended-release tablets. The criteria used were the ability of the chitosans to reduce Cu2+, and hydroxyl and superoxide radicals and N-centered radicals derived from 1,1\u27-diphenyl-2-picrylhydrazyl, via the use of ESR spectrometry. CS2 showed the highest scavenging activity. CS1 and CS3, however, were much less effective and CS4 was not a viable antioxidant. The results suggest that CS2 could be useful in combating the development of oxidative stress. A series of chitosan tablets were prepared using a spray drying method and evaluated as an extended-release matrix tablet using theophylline (TPH) as a model drug. The release of TPH from the different MW chitosan tablets increased with increasing MW of the chitosan used. CS2, CS3 and CS4 showed a reasonable release activity, but CS1 showed the shortest release activity. Moreover, the CS2-TPH tablet showed the highest scavenging activity of the three chitosan tablets (CS2-CS4) using 2,2\u27-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radicals. These results suggest that a CS2-TPH tablet could be potentially useful in an extended-release matrix tablet with a high antioxidant activity.The antioxidant properties of different low molecular weight (LMW) chitosans (CS1; 22 kDa, CS2; 38 kDa, CS3; 52 kDa, CS4; 81 kDa) were examined for possible use in extended-release tablets. The criteria used were the ability of the chitosans to reduce Cu2+, and hydroxyl and superoxide radicals and N-centered radicals derived from 1,1\u27-diphenyl-2-picrylhydrazyl, via the use of ESR spectrometry. CS2 showed the highest scavenging activity. CS1 and CS3, however, were much less effective and CS4 was not a viable antioxidant. The results suggest that CS2 could be useful in combating the development of oxidative stress. A series of chitosan tablets were prepared using a spray drying method and evaluated as an extended-release matrix tablet using theophylline (TPH) as a model drug. The release of TPH from the different MW chitosan tablets increased with increasing MW of the chitosan used. CS2, CS3 and CS4 showed a reasonable release activity, but CS1 showed the shortest release activity. Moreover, the CS2-TPH tablet showed the highest scavenging activity of the three chitosan tablets (CS2-CS4) using 2,2\u27-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radicals. These results suggest that a CS2-TPH tablet could be potentially useful in an extended-release matrix tablet with a high antioxidant activity

Useful Extend-release Chitosan Tablets with High Antioxidant Activity

The antioxidant properties of different low molecular weight (LMW) chitosans (CS1; 22 kDa, CS2; 38 kDa, CS3; 52 kDa, CS4; 81 kDa) were examined for possible use in extended-release tablets. The criteria used were the ability of the chitosans to reduce Cu2+, and hydroxyl and superoxide radicals and N-centered radicals derived from 1,1'-diphenyl-2-picrylhydrazyl, via the use of ESR spectrometry. CS2 showed the highest scavenging activity. CS1 and CS3, however, were much less effective and CS4 was not a viable antioxidant. The results suggest that CS2 could be useful in combating the development of oxidative stress. A series of chitosan tablets were prepared using a spray drying method and evaluated as an extended-release matrix tablet using theophylline (TPH) as a model drug. The release of TPH from the different MW chitosan tablets increased with increasing MW of the chitosan used. CS2, CS3 and CS4 showed a reasonable release activity, but CS1 showed the shortest release activity. Moreover, the CS2-TPH tablet showed the highest scavenging activity of the three chitosan tablets (CS2-CS4) using 2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radicals. These results suggest that a CS2-TPH tablet could be potentially useful in an extended-release matrix tablet with a high antioxidant activity

Antioxidant properties of some different molecular weight chitosans

Chitosan, a cationic polysaccharide, is widely employed as dietary supplement and in pharmacological and biomedical applications. Although numerous studies have focused on its applications as pharmaceutical excipients or bioactive reagents, relationships between molecular weight (Mr) and biological properties remain unclear. The focus of this study was on the antioxidant properties of several Mr chitosans. We measured the ability of seven Mr chitosans (CT1; 2.8 kDa, CT2; 17.0 kDa, CT3; 33.5 kDa, CT4; 62.6 kDa, CT5; 87.7 kDa, CT6; 604 kDa, CT7; 931 kDa) to protect plasma protein from oxidation by peroxyl radicals derived from 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH). A comparison of the antioxidant action of high Mr chitosans (CT6–CT7) with that of low Mr chitosans (CT1–CT5) showed that low Mr chitosans (CT1–CT5) were more effective in preventing the formation of carbonyl groups in plasma protein exposed to peroxyl radicals. AAPH substantially increases plasma protein carbonyl content via the oxidation of human serum albumin (HSA). We also measured the ability of these chitosans to protect HSA against oxidation by AAPH. Low Mr chitosans (CT1–CT5) were found to effectively prevent the formation of carbonyl groups in HSA, when exposed to peroxyl radicals. Low Mr chitosans were also good scavengers of N-centered radicals, but high Mr chitosans were much less effective. We also found a strong correlation between antioxidant activity and the Mr of chitosans in vitro. These activities were also determined by using the ‘TPAC’ test. These results suggest that low Mr chitosans (CT1–CT3) may be absorbed well from the gastrointestinal tract and inhibit neutrophil activation and oxidation of serum albumin that is frequently observed in patients plasma undergoing hemodialysis, resulting in a reduction in oxidative stress associated with uremia.7 page(s