Gastrointestinal transit of pellets of differing size and density

Clarke, Gerard; Newton, John; Short, Michael D.

doi:10.1016/0378-5173(93)90078-t

Cited by 95 publications

(62 citation statements)

References 11 publications

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“…Recently several gastroretentive approaches like swelling devices (4,5), floating systems (2,6), bioadhesive systems (7), low density systems (8), high density systems (9), expandable systems (10), superporous, biodegradable hydrogels (2,11,12), and magnetic systems (13) have been developed. To increase the gastric retention time (GRT), one should have a thorough knowledge about the physiology of GIT, and all the limitations should be well understood.…”

Section: Introductionmentioning

confidence: 99%

Formulation and Evaluation of Swellable and Floating Gastroretentive Ciprofloxacin Hydrochloride Tablets

2009

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Abstract. Drugs that have narrow absorption window in the gastrointestinal tract (GIT) will have poor absorption. For these drugs, gastroretentive drug delivery systems offer the advantage in prolonging the gastric emptying time. Swellable, floating, and sustained release tablets are developed by using a combination of hydrophilic polymer (hydroxypropyl methylcellulose), swelling agents (crospovidone, sodium starch glycolate, and croscarmelose sodium) and effervescent substance (sodium bicarbonate). Formulations are evaluated for percentage swelling, in vitro drug release, floating lag time, total duration of floating, and mean residence time (MRT) in the stomach. The drug release of optimized formulation follows the Higuchi kinetic model, and the mechanism is found to be non-Fickian/anomalous according to Krosmeyer-Peppas (n value is 0.68). The similarity factor (f 2 ) is found to be 26.17 for the optimized formulation, which the release is not similar to that of marketed produced (CIFRAN OD®). In vivo nature of the tablet at different time intervals is observed in the radiographic pictures of the healthy volunteers and MRT in the stomach is found to be 320±48.99 min (n=6). A combination of HPMC K100M, crospovidone, and sodium carbonate shows the good swelling, drug release, and floating characters than the CIFRAN OD®.

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Section: Introductionmentioning

confidence: 99%

Formulation and Evaluation of Swellable and Floating Gastroretentive Ciprofloxacin Hydrochloride Tablets

2009

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“…Vári-os estudos (Sugito et al, 1992;Clarke, Newton, Short, 1993) foram conduzidos em modelos animais e em humanos, por forma a encontrar o tamanho crítico, abaixo do qual as formas farmacêuticas exibiam um comportamento mais previsível nos seus tempos de esvaziamento gástrico. Apesar de alguns valores terem sido referidos, a variabilidade intra e interindividual dos tempos de esvaziamento gástrico, bem como as limitações da extrapolação dos resultados em modelos animais para o Homem, leva-nos a ser cautelosos na interpretação desses resultados.…”

Section: Tempo De Esvaziamento Gástricounclassified

Liberação específica de fármacos para administração no cólon por via oral. I - O cólon como local de liberação de fármacos

Freire¹,

Podczeck²,

Sousa³

et al. 2006

Rev. Bras. Cienc. Farm.

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“…Inert materials used to increase the density of formulations are used either by coating the drug with it or by mixing the material with the drug (Vyas and Khar, 2006). On addition of such inert materials, the formulation density can increase by up to 1.5--2.4 g/cm 3 (Clarke et al, 1993). One major drawback, however is that they are difficult to manufacture, requiring relatively large quantities of active drug as the dry material constituent of the formulation reacts with the gastric fluid to release its contents.…”

Section: High Density Systemsmentioning

confidence: 99%

“…The density of the formulation should be close to 2.5 g/cm 3 , for it to be retained in the stomach for any considerable length of time (Clarke et al, 1993 , formulations can be retained in the lower part of the stomach (Rouge et al, 1998). Inert materials used to increase the density of formulations are used either by coating the drug with it or by mixing the material with the drug (Vyas and Khar, 2006).…”

Section: High Density Systemsmentioning

confidence: 99%

Gastroretentive microparticles for drug delivery applications

Adebisi

Conway

2011

Journal of Microencapsulation

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Many strategies have been proposed to explore the possibility of exploiting gastroretention for drug delivery. Such systems would be useful for local delivery, for drugs that are poorly soluble at higher pH or primarily absorbed from the proximal small intestine. Generally, the requirements of such strategies are that the vehicle maintains controlled drug release and exhibits prolonged residence time in the stomach. Despite widespread reporting of technologies, many have an inherent drawback of variability in transit times. Microparticulate systems, capable of distributing widely through the GI tract, can potentially minimize this variation. While being retained in the stomach, the drug content is released slowly at a desired rate,

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Gastrointestinal transit of pellets of differing size and density

Cited by 95 publications

References 11 publications

Formulation and Evaluation of Swellable and Floating Gastroretentive Ciprofloxacin Hydrochloride Tablets

Formulation and Evaluation of Swellable and Floating Gastroretentive Ciprofloxacin Hydrochloride Tablets

Liberação específica de fármacos para administração no cólon por via oral. I - O cólon como local de liberação de fármacos

Gastroretentive microparticles for drug delivery applications

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