Development of pH- and enzyme-controlled, colon-targeted, pulsed delivery system of a poorly water-soluble drug: preparation and in vitro evaluation

Lai, Huiming; Lin, Ke; Zhang, Wenbin; Zhang, Zhirong; Liu, Jie; Wu, Yuna; He, Qin

doi:10.3109/03639040903092335

Cited by 13 publications

(6 citation statements)

References 28 publications

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“…The effect of PPIs was examined by using CT26 mouse colon cancer cells treated with pantoprazole and/or alkaline media[14] (Figure 1). PPI treatment did not affect cell proliferation of CT26 cells regardless of glucose concentration (Figure 1A).…”

Section: Resultsmentioning

confidence: 99%

“…Expression of transforming growth factor (TGF) β and fibroblast growth factor (FGF) 2 was increased by treatment with PPI or alkaline media. TGF-β and FGF2 are known to stimulate collagen-producing fibroblasts[14]. In contrast, expression of replication factor C1 ( RFC1 orAlp145 ), a negative regulator of collagen expression[15], was downregulated by treatment with PPI or alkaline media.…”

Section: Resultsmentioning

confidence: 99%

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Proton pump inhibitor induced collagen expression in colonocytes is associated with collagenous colitis

Mori

Kadochi

Luo

et al. 2017

WJG

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AIMTo elucidate the role of proton pump inhibitors (PPIs) in collagenous disease, direct effect of PPI on colonocytes was examined.METHODSCollagenous colitis is a common cause of non-bloody, watery diarrhea. Recently, there has been increasing focus on the use of proton PPIs as a risk factor for developing collagenous colitis. Mouse CT26 colonic cells were treated with PPI and/or PPI-induced alkaline media. Expression of fibrosis-associated genes was examined by RT-PCR. In human materials, collagen expression was examined by immunohistochemistry.RESULTSCT26 cells expressed a Na+-H+ exchanger gene (solute carrier family 9, member A2). Treatment with PPI and/or PPI-induced alkaline media caused growth inhibition and oxidative stress in CT26 cells. The treatment increased expression of fibrosis inducing factors, transforming growth factor β and fibroblast growth factor 2. The treatment also decreased expression of a negative regulator of collagen production, replication factor C1, resulting in increased expression of collagen types III and IV in association with lipid peroxide. In biopsy specimens from patients with collagenous colitis, type III and IV collagen were increased. Increase of type III collagen was more pronounced in PPI-associated collagenous colitis than in non-PPI-associated disease.CONCLUSIONFrom these findings, the reaction of colonocytes to PPI might participate in pathogenesis of collagenous colitis.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Proton pump inhibitor induced collagen expression in colonocytes is associated with collagenous colitis

Mori

Kadochi

Luo

et al. 2017

WJG

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“…The enzyme degradation kinetics of pectin has been enhanced by blending it with other polymers such as ethylcellulose, hydroxypropylmethylcellulose, chitosan, poly(lysine), and polyacrylate derivatives containing quaternary ammonium groups to take advantage of the enzymatic repertoire of the bacterial flora in the presence of co-encapsulated enzyme co-factors to potentiate their action [183]. Lai and colleagues exposed guar gum to a simulated colonic fluid containing β-mannanase and demonstrated in situ pore generation by ionic interactions and the subsequent cargo release [184]. Other materials used for colon targeting include amylose combined with ethylcellulose, galactomannan, inulin, and dextran [185].…”

Section: Enzyme-responsive Matricesmentioning

confidence: 99%

“…Ionic strength has proven to have a marked effect on charged poly(N-isopropyl acrylamide) (PolyNIPAM) hydrogels, altering their swelling/shrinking behavior [37,184]. In this regard, it has been observed that a strongly charged hydrogel is likely to swell at low ionic strengths due to the strong interchain electrostatic repulsion but shrinks at high ionic strengths due to electrostatic screening effects [187].…”

Section: Ionic Strength and Redox-responsive Matricesmentioning

confidence: 99%

Novel Developments on Stimuli-Responsive Probiotic Encapsulates: From Smart Hydrogels to Nanostructured Platforms

et al. 2022

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Biomaterials engineering and biotechnology have advanced significantly towards probiotic encapsulation with encouraging results in assuring sufficient bioactivity. However, some major challenges remain to be addressed, and these include maintaining stability in different compartments of the gastrointestinal tract (GIT), favoring adhesion only at the site of action, and increasing residence times. An alternative to addressing such challenges is to manufacture encapsulates with stimuli-responsive polymers, such that controlled release is achievable by incorporating moieties that respond to chemical and physical stimuli present along the GIT. This review highlights, therefore, such emerging delivery matrices going from a comprehensive description of addressable stimuli in each GIT compartment to novel synthesis and functionalization techniques to currently employed materials used for probiotic’s encapsulation and achieving multi-modal delivery and multi-stimuli responses. Next, we explored the routes for encapsulates design to enhance their performance in terms of degradation kinetics, adsorption, and mucus and gut microbiome interactions. Finally, we present the clinical perspectives of implementing novel probiotics and the challenges to assure scalability and cost-effectiveness, prerequisites for an eventual niche market penetration.

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“…Dissolution testing of polysaccharide-based oral colon-targeted delivery systems is a consistent challenge due to the varying pH, viscosity, presence of diverse microbiota, and motility conditions in the upper GI segments that the system needs to traverse before reaching the colon. [ 1 ] This challenge is further intensified by the diverse strategies used in the formulation of colon-targeted delivery systems, their release being designed to be facilitated by stimuli such as pH,[ 2 3 ] pH and time,[ 2 ] presence of enzymes,[ 4 ] time,[ 6 7 8 9 ] using prodrug based,[ 7 ] pressure controlled,[ 10 ] and microbially triggered delivery systems. [ 11 12 13 14 15 16 17 18 ] The most commonly reported medium to evaluate all these types of delivery systems is the one that utilizes colon contents of rodents.…”

Section: Introductionmentioning

confidence: 99%

Novel biorelevant dissolution medium as a prognostic tool for polysaccharide-based colon-targeted drug delivery system

Yadav

Sadora

Singh

et al. 2017

J Adv Pharm Technol Res

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To overcome the limitations of the conventionally used methods for evaluation of orally administered colon-targeted delivery systems, a novel dissolution method using probiotics has been recently reported. In the present study, universal suitability of this medium composed of five different probiotics is established. Different delivery systems – mini tablets, liquisolid compacts, and microspheres coated with different polysaccharides – were prepared and subjected to sequential dissolution testing in medium with and without microbiota. The results obtained from fluid thioglycollate medium (FTM)-based probiotic medium for all the polysaccharide-based formulations showed statistically similar dissolution profile to that in the rat and goat cecal content media. Hence, it can be concluded that the developed FTM-based probiotic medium, once established, may eliminate the need for further animal sacrifice in the dissolution testing of polysaccharide-based colon-targeted delivery system.

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Development of pH- and enzyme-controlled, colon-targeted, pulsed delivery system of a poorly water-soluble drug: preparation and in vitro evaluation

Abstract: The above results indicated this system could be served as a potential carrier to deliver poorly water-soluble drug specifically to the colon.

Cited by 13 publications

References 28 publications

Proton pump inhibitor induced collagen expression in colonocytes is associated with collagenous colitis

Proton pump inhibitor induced collagen expression in colonocytes is associated with collagenous colitis

Novel Developments on Stimuli-Responsive Probiotic Encapsulates: From Smart Hydrogels to Nanostructured Platforms

Novel biorelevant dissolution medium as a prognostic tool for polysaccharide-based colon-targeted drug delivery system

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