Enteric coatings for colonic drug delivery: state of the art

Maroni, Alessandra; Moutaharrik, Saliha; Gazzaniga, A.

doi:10.1080/17425247.2017.1360864

Cited by 47 publications

(28 citation statements)

References 21 publications

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“…As a result, drug delivery systems coated with pH-dependent polymers having a dissolution threshold of pH 6.0-7.0 are expected to delay the drug dissolution and prevent premature drug release in the upper GI tract before reaching colonic sites [15]. However, this pH-dependent system has demonstrated significant variability in drug release and failure in vivo due to the vast inter-and intra-subject variability in critical parameters including pH, fluids volumes, GI transit times, and motility [16]. Furthermore, pH ranges of GI tract can be significantly altered by diet, disease state, water intake, and microbial metabolism [17].…”

Section: Ph-dependent Drug Delivery Systemsmentioning

confidence: 99%

“…Furthermore, pH ranges of GI tract can be significantly altered by diet, disease state, water intake, and microbial metabolism [17]. For example, patients with ulcerative colitis exhibit more acidic colonic pH compared to healthy humans, leading to incomplete drug release from enteric coated systems at the target site [16]. Thus, the dynamic pH change by many internal and external factors may attenuate the efficiency of pH-dependent drug release systems, often leading to poorly site-selective drug release.…”

Section: Ph-dependent Drug Delivery Systemsmentioning

confidence: 99%

“…To overcome this limitation of pH-dependent delivery systems, there have been attempts to use the combination of pH-dependent systems with other delivery systems including time-dependent systems and enzyme-triggered systems. For example, Eudragit ® S were blended with high-amylose maize starch for the integration of pH-dependent system and colonic microbial degradation systems [16,20].…”

Section: Ph-dependent Drug Delivery Systemsmentioning

confidence: 99%

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Strategic Approaches for Colon Targeted Drug Delivery: An Overview of Recent Advancements

et al. 2020

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Colon targeted drug delivery systems have gained a great deal of attention as potential carriers for the local treatment of colonic diseases with reduced systemic side effects and also for the enhanced oral delivery of various therapeutics vulnerable to acidic and enzymatic degradation in the upper gastrointestinal tract. In recent years, the global pharmaceutical market for biologics has grown, and increasing demand for a more patient-friendly drug administration system highlights the importance of colonic drug delivery as a noninvasive delivery approach for macromolecules. Colon-targeted drug delivery systems for macromolecules can provide therapeutic benefits including better patient compliance (because they are pain-free and can be self-administered) and lower costs. Therefore, to achieve more efficient colonic drug delivery for local or systemic drug effects, various strategies have been explored including pH-dependent systems, enzyme-triggered systems, receptor-mediated systems, and magnetically-driven systems. In this review, recent advancements in various approaches for designing colon targeted drug delivery systems and their pharmaceutical applications are covered with a particular emphasis on formulation technologies.

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Section: Ph-dependent Drug Delivery Systemsmentioning

confidence: 99%

Section: Ph-dependent Drug Delivery Systemsmentioning

confidence: 99%

Section: Ph-dependent Drug Delivery Systemsmentioning

confidence: 99%

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Strategic Approaches for Colon Targeted Drug Delivery: An Overview of Recent Advancements

et al. 2020

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“…Since the dissolution of the coating takes some time (depending on its thickness and exact pH threshold value), these systems should prevent the release of the incorporated drugs in the stomach and proximal bowel and release the drug in the subsequent parts of the gastrointestinal tract. However, both premature drug release in the small intestine, as well as no drug release at all, have been reported as potential failures [18]. This can be attributed to the significant variability of the pH of the contents of the different segments of the gastrointestinal tract.…”

Section: Introductionmentioning

confidence: 99%

Injection Molded Capsules for Colon Delivery Combining Time-Controlled and Enzyme-Triggered Approaches

Casati

Melocchi

Moutaharrik

et al. 2020

IJMS

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A new type of colon targeting system is presented, combining time-controlled and enzyme-triggered approaches. Empty capsule shells were prepared by injection molding of blends of a high-amylose starch and hydroxypropyl methylcellulose (HPMC) of different chain lengths. The dissolution/erosion of the HPMC network assures a time-controlled drug release, i.e., drug release starts upon sufficient shell swelling/dissolution/erosion. In addition, the presence of high-amylose starch ensures enzyme-triggered drug release. Once the colon is reached, the local highly concentrated bacterial enzymes effectively degrade this polysaccharide, resulting in accelerated drug release. Importantly, the concentration of bacterial enzymes is much lower in the upper gastrointestinal tract, thus enabling site-specific drug delivery. The proposed capsules were filled with acetaminophen and exposed to several aqueous media, simulating the contents of the gastrointestinal tract using different experimental setups. Importantly, drug release was pulsatile and occurred much faster in the presence of fecal samples from patients. The respective lag times were reduced and the release rates increased once the drug started to be released. It can be expected that variations in the device design (e.g., polymer blend ratio, capsule shell geometry and thickness) allow for a large variety of possible colon targeting release profiles.

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“…This enhances the efficacy and tolerability associated with the therapy, by increasing the dose fraction reaching the inflamed mucosa and reducing that entering the systemic circulation due to poor colonic absorption In order to obtain effective levels of 5-ASA in the large bowel following oral intake, proper delivery strategies need to be used (Karrout et al, 2015;Qureshi and Cohen, 2005;Sardo et al, 2019). The vast majority of commercially-available 5-ASA products relate to a pH-dependent strategy (Maroni et al, 2017b;Sandborn and Hanauer, 2003). The basic concept behind that is the aboral increase in the gastrointestinal pH, which ranges from acidic values of the gastric fluid to neutral or slightly alkaline ones of the distal intestine contents.…”

Section: Introductionmentioning

confidence: 99%

In vitro and human pharmacoscintigraphic evaluation of an oral 5-ASA delivery system for colonic release

Foppoli

Moutaharrik

Melocchi

et al. 2019

International Journal of Pharmaceutics

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5-aminosalicylic acid (5-ASA) is the most widely used drug for the treatment of ulcerative colitis. The benefits of targeted delivery of 5-ASA to the large intestine are well known, resulting in reduced systemic absorption and increased local concentrations at the disease site. In the present study, a 5-ASA colon delivery system based on the time-dependent strategy, exploiting the relatively consistent small intestinal transit time (SITT), was manufactured and evaluated in vitro as well as in vivo. The system was obtained by successive spray-coating of an immediate-release tablet core with lowviscosity HPMC and Eudragit  L. The enteric film was effective in preventing release during the acidic stage of the in vitro test, while the HPMC coating brought about reproducible lag phases prior to release in phosphate buffer medium. A γ-scintigraphy investigation pointed out that, following administration to fasted and fed volunteers, disintegration of the units never occurred prior to colon arrival. In all cases, a lag time preceded the appearance of the drug and its N-acetyl metabolite in the bloodstream, which was found to correlate with the time of disintegration in a linear mode. The plasma levels of the drug and metabolite as well as their cumulative urinary recovery were relatively low with respect to those reported when 5-ASA is delivered to the small bowel.

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Enteric coatings for colonic drug delivery: state of the art

Cited by 47 publications

References 21 publications

Strategic Approaches for Colon Targeted Drug Delivery: An Overview of Recent Advancements

Strategic Approaches for Colon Targeted Drug Delivery: An Overview of Recent Advancements

Injection Molded Capsules for Colon Delivery Combining Time-Controlled and Enzyme-Triggered Approaches

In vitro and human pharmacoscintigraphic evaluation of an oral 5-ASA delivery system for colonic release

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