Amylose as a coating for drug delivery to the colon: Preparation and in vitro evaluation using glucose pellets

Milojevic, Snezana; Newton, JM; Cummings, J.H.; Gibson, G. B.; Botham, R.L.; Ring, Stephen G.; Stockham, M. A.; Allwood, M. C.

doi:10.1016/0168-3659(95)00113-1

Cited by 72 publications

(26 citation statements)

References 10 publications

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“…This problem was overcome by incorporating the water-insoluble polymer, ethylcellulose, in the form of an aqueous dispersion, into the coating formulation. These mixed coating formulations exhibited in vitro resistance to gastric and small intestinal conditions yet remained sensitive to digestion by enzymes of colonic bacterial origin [ 9,10]. Testing in human volunteers verified the results obtained in vitro [3,11], thereby confirming the colon-specificity of these amylose-based delivery systems.…”

Section: Introductionsupporting

confidence: 50%

The potential of organic-based amylose-ethylcellulose film coatings as oral colon-specific drug delivery systems

2000

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Amylose-ethylcellulose film coatings obtained from organic-based solvents were investigated as potential vehicles for colonic drug delivery. Amylose, in the form of an amylose-butan-1-ol dispersion, and ethylcellulose, dissolved in either ethyl lactate, ethanol, or propanol and plasticized with dibutyl sebacate, were mixed in various proportions and applied using a fluidized bed coater to achieve a range of film thicknesses on 5-aminosalicylic acid pellets. Drug release from the coated pellets was assessed under gastric and small intestinal conditions in the presence and absence of pepsin and pancreatin using dissolution methodology, and also within a simulated colonic environment involving fermentation testing with human feces in the form of a slurry. Under upper gastrointestinal tract conditions, the rate and extent of drug release were found to be related to the thickness of the coating and the ratio of amylose to ethylcellulose within the film. Modeling of the drug release data revealed that the ratio was more important than coat thickness in controlling drug release, irrespective of the solvent used for coating. Coatings with a thick film and/or low amylose content were relatively impermeable and able to delay drug release under conditions mimicking the upper gastrointestinal tract. Furthermore, drug release was unaffected by the presence of pepsin and pancreatin and by long-term storage. Under simulated colonic conditions, drug release was more pronounced from coating formulations containing higher proportions of amylose. Colon-specificity can therefore be achieved using such systems by judicious choice of the appropriate ratio of amylose to ethylcellulose and coat thickness.

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Section: Introductionsupporting

confidence: 50%

The potential of organic-based amylose-ethylcellulose film coatings as oral colon-specific drug delivery systems

2000

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“…Therefore, the length of dissolution was set to 12 hours considering the passage of pellets through the gastrointestinal tract and the required length of lag time. Longer dissolution times would be suitable for studying glucose release in the colon (19). One dissolution profile was acquired for each coating level, resulting in three different profiles for each composition (Fig.…”

Section: In Vitro Glucose Releasementioning

confidence: 99%

Coated pellets with delayed-release glucose for prevention of hypoglycemic episodes

et al. 2016

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Patients tend to prevent hypoglycemia by excessive saccharide intake leading to poorer glycemic control with potentially fatal consequences. This problem could be resolved by means of pellets with glucose release delayed by 120-360 min as a compensation of the antidiabetic drug peak effect. No glucose is released before; hence there is no risk of hyperglycemia and secondary complications. The pellets contain glucose in combination with an osmotically active ingredient and are coated with an ethylcellulose dispersion, which forms an insoluble semipermeable membrane and ensures delayed release. The release of glucose was assessed using dissolution and high-performance liquid chromatography. Dissolution profiles indicated the possibility of achieving the requested lag time using a combination of adequate compositions and coating concentrations. Lag times of 60, 240 and 360 min were achieved. The sample containing carboxymethyl starch was found to be most suitable for the intent of this work.Keywords: hypoglycemia, diabetes mellitus, pellets, delayed release, glucose, pellet evaluation Hypoglycemia is a common, dangerous and usually unpredictable complication in diabetes mellitus therapy. It can be defined as the occurrence of a variety of symptoms associated with plasma glucose concentration lowered under 3.9 mmol/l (1, 2). If untreated, hypoglycemia can lead to seizures, coma, and death (3). Hypoglycemia frequently develops as a result of misbalance between the effect of insulin or peroral antidiabetics and food intake. Hypoglycemia during sport activities, nocturnal hypoglycemia and hypoglycemia caused by irregular diet are typical examples of such situations.Children and adolescent are more vulnerable to hypoglycemia than adults. Many factors induce the risk of hypoglycemia in young patients. Children and adolescent tend to eat erratically and perform physical activity irregularly, making it difficult to ensure optimal glucose levels during the day. Moreover, hypoglycemic symptoms may be difficult for children to recognize and verbalize, which can lead to longer delays in treatment and in-

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“…Em estudos posteriores (Milojevic et al, 1995c) prepararam-se peletes revestidos com amilose e Ethocel ® numa relação de 1:4. O fármaco modelo utilizado foi a glucose marcada com 13 C e a validação do revestimento realizou-se determinando o 13 CO 2 no ar expirado e por γ-cintigrafia.…”

Section: Hidróliseunclassified

Liberação específica de fármacos no cólon por via oral. II - Tipos de sistemas utilizados

Freire¹,

Podczeck²,

Sousa³

et al. 2006

Rev. Bras. Cienc. Farm.

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Amylose as a coating for drug delivery to the colon: Preparation and in vitro evaluation using glucose pellets

Cited by 72 publications

References 10 publications

The potential of organic-based amylose-ethylcellulose film coatings as oral colon-specific drug delivery systems

The potential of organic-based amylose-ethylcellulose film coatings as oral colon-specific drug delivery systems

Coated pellets with delayed-release glucose for prevention of hypoglycemic episodes

Liberação específica de fármacos no cólon por via oral. II - Tipos de sistemas utilizados

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