Sigmoidal release of indomethacin from pectin matrix tablets: Effect of in situ crosslinking by calcium cations

Wei, Xiuli; Sun, Ningyun; Wu, Baojian; Chen, Yin; Wu, Wei

doi:10.1016/j.ijpharm.2006.03.024

Cited by 63 publications

(48 citation statements)

References 30 publications

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“…A lag time over 3 h can easily be attained using the compression-coated system, whereas a matrix system that is composed of the same amounts of pectin and calcium chloride cannot achieve this lag time due to the matrix erosion (Wei et al, 2006). The lag time appeared to be related to gel thickness rather than calcium chloride content, since similar lag times were observed for tablets with different ratios of calcium chloride in the coating layer (Figure 1).…”

Section: Effect Of the P/ca Ratio And Coating Weight On Release Profilesmentioning

confidence: 93%

“…Indomethacin in tablets and release media were determined using a HPLC method (Wei et al, 2006). The Agilent 1100 series HPLC system consisted of a quaternary pump, a degasser, an autosampler, a column heater and a tunable wavelength UV detector.…”

Section: Determination Of Indomethacin In Tablets Release Media and mentioning

confidence: 99%

“…Release tests were performed in ZRS-8 G dissolution tester (Tianjin, China) and were based on the Chinese Pharmacopoeia Method I (Wei et al, 2006). Basket rotation speed was set to 100 rpm.…”

Section: Release Studymentioning

confidence: 99%

“…Nevertheless, the in situ crosslinking P/Ca system might be suitable for use as a compression coating material in colon-specific drug delivery. In the previous study, complete erosion of a 75/75 (mg/mg) P/Ca matrix occurred in 4 h (Wei et al, 2006). Therefore, it is reasonable to assume that a P/Ca compression-coated tablet, with a heavier coating and the proper P/Ca ratio, may prevent premature release of a drug.…”

Section: Introductionmentioning

confidence: 95%

“…In previous study, we reported that fortification of pectin gels could be achieved via calcium cation-induced in situ crosslinking (Wei et al, 2006(Wei et al, , 2009Wu et al, 2007a;Wu et al, 2008). Consequently, significant slowing of the initial drug release and a sigmoid release pattern were observed with use of these pectin/calcium chloride (P/Ca) matrix systems.…”

Section: Introductionmentioning

confidence: 99%

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Anin situcrosslinked compression coat comprised of pectin and calcium chloride for colon-specific delivery of indomethacin

Wei

Lü

et al. 2014

Drug Delivery

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(2015) An insitu crosslinked compression coat comprised of pectin and calcium chloride for colon-specific delivery of indomethacin, Drug Delivery, 22:3, 298-305, DOI: 10.3109/10717544.2013 AbstractThe use of pectin for colon-specific drug delivery has been extensively investigated; however, when used alone, pectin is often compromised due to its high solubility. This study explored the feasibility of using an in situ compression-coated crosslinking system, composed of pectin and calcium chloride, for colon-specific drug delivery. A pectin/calcium chloride (P/Ca) coating was compressed onto a core tablet. The colon specificity of the compression-coated tablet was verified by dissolution, pharmacokinetics and scintigraphy with 99m Tc labeling. The in situ pectin and calcium chloride gel slowed the release of indomethacin. The lag time varied between 3 h and 7 h depending on the amount of calcium chloride and the coating weight. Pectinase triggered the release of indomethacin from the compression-coated tablet, which was then accelerated by the calcium chloride in the coating layer. The compression-coated tablet had a prolonged t max and apparent t 1/2 , as well as a decreased C max and AUC 0-t , compared with the core tablet counterpart. Evaluation with g-scintigraphy verified colonspecific delivery of the compression-coated tablet. In conclusion, the P/Ca in situ crosslinking system worked well for colon-specific drug delivery.

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Section: Effect Of the P/ca Ratio And Coating Weight On Release Profilesmentioning

confidence: 93%

Section: Determination Of Indomethacin In Tablets Release Media and mentioning

confidence: 99%

Section: Release Studymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Anin situcrosslinked compression coat comprised of pectin and calcium chloride for colon-specific delivery of indomethacin

Wei

Lü

et al. 2014

Drug Delivery

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Physicochemical characterization of a pectin/calcium matrix containing a large fraction of calcium chloride: Implications for sigmoidal release characteristics

Wei

Chen

Lü

et al. 2009

J of Applied Polymer Sci

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The physicochemical properties of pectin/ calcium matrix tablets were studied with an emphasis on the effect of over 50% of calcium chloride to better understand the fundamentals of the drug-release mechanisms. The absence of the adsorption of methylene blue onto the calciumcontaining pectin matrix served as evidence of the calciumion-induced in situ crosslinking of pectin chains. Visual and scanning electron microscopy observation showed the reinforced robustness of the pectin/calcium matrix, whereas cryo-SEM revealed the formation of a pectin aggregate network as a result of calcium-induced crosslinking. The aggregate network underwent gradual erosion to a lower density, which indicated the erosion of the matrix. However, little change in the texture of the pectin/calcium matrix was observed at earlier times, which was interpreted as the initial stages of drug-release retardation. The apparent viscosity of the pectin aqueous dispersion increased biphasically as the calcium amount increased. The initial sharp increase was interpreted as calcium-induced crosslinking, whereas the following gradual increase was ascribed to a possible salt effect. We concluded that the salt effect and calcium-induced crosslinking contributed to a series of physical changes of the pectin matrix, which correlated to the sigmoidal release of indomethacin from the pectin/calcium matrix tablet.

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Tetracycline release from chitosan/fish‐scale‐based membranes

Cortes

Vieira

Cestari

et al. 2013

J of Applied Polymer Sci

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In this study, we aimed to develop new biocompatible membranes on the basis of chitosan (CHIT) and fish scale powder (ESC) from the species Leporinus elongatus. The possibility of using the uncrosslinked membrane (ESC/CHIT) and membrane crosslinked with sodium tetraborate (ESC/CHIT‐B) for tetracycline release was investigated. The drug‐release kinetics were studied at 30 and 37°C in phosphate buffered saline (pH 7.4). For ESC/CHIT, the drug release was faster, about 6 days, whereas the release time of tetracycline impregnated in ESC/CHIT‐B was about 7 days. The in vitro release behavior of tetracycline from both membranes followed the Peppas and Higuchi kinetic models. The kinetics of drug release from ESC/CHIT were regarded as a coupled diffusion/polymer relaxation mechanism, whereas drug release from ESC/CHIT‐B seemed to be controlled by polymer relaxation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39943.

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Sigmoidal release of indomethacin from pectin matrix tablets: Effect of in situ crosslinking by calcium cations

Cited by 63 publications

References 30 publications

Anin situcrosslinked compression coat comprised of pectin and calcium chloride for colon-specific delivery of indomethacin

Anin situcrosslinked compression coat comprised of pectin and calcium chloride for colon-specific delivery of indomethacin

Physicochemical characterization of a pectin/calcium matrix containing a large fraction of calcium chloride: Implications for sigmoidal release characteristics

Tetracycline release from chitosan/fish‐scale‐based membranes

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