Ascertain a minimum coating thickness for acid protection of enteric coatings by means of optical coherence tomography

Wolfgang, Matthias; Stranzinger, Sandra; Khinast, Johannes

doi:10.1016/j.ijpharm.2022.121680

Cited by 19 publications

(7 citation statements)

References 35 publications

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“…Thus, thin films of poly(vinylpyrrolidone), dextran, alginate, gold, polyelectrolyte, gelatin, and chitosan have been applied to films and particulates and demonstrated to delay crystallization. − However, these techniques fall into more traditional definitions of co-processing with noncovalently bonded materials, where the control of film deposition and conformality (i.e., having a constant thickness on horizontal and vertical surfaces) and effectiveness (to its intended function) is based on ionic interactions of the substrate/coating, adhesive qualities of the coating material, substrate smoothness, coating porosity, and permeability, and ultimately, relatively thick layers applied from a solvent system are likely to be required. Thickness of coating layers found with traditional coatings is quite high, on the order of tens or hundreds of microns …”

Section: Introductionmentioning

confidence: 99%

“…Thickness of coating layers found with traditional coatings is quite high, on the order of tens or hundreds of microns. 38 A traditional pharmaceutical coating process applies a polymeric film to impart aesthetics or functionality, such as taste masking, controlled release, or improved mechanical integrity. 39 The polymeric film is applied by spraying an aqueous or organic solvent solution onto the substrate, followed by a drying step.…”

Section: ■ Introductionmentioning

confidence: 99%

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Atomic Layer Coating to Inhibit Surface Crystallization of Amorphous Pharmaceutical Powders

Moseson

Benson

Nguyen

et al. 2022

ACS Appl. Mater. Interfaces

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Preventing crystallization is a primary concern when developing amorphous drug formulations. Recently, atomic layer coatings (ALCs) of aluminum oxide demonstrated crystallization inhibition of high drug loading amorphous solid dispersions (ASDs) for over 2 years. The goal of the current study was to probe the breadth and mechanisms of this exciting finding through multiple drug/polymer model systems, as well as particle and coating attributes. The model ASD systems selected provide for a range of hygroscopicity and chemical functional groups, which may contribute to the crystallization inhibition effect of the ALC coatings. Atomic layer coating was performed to apply a 5–25 nm layer of aluminum oxide or zinc oxide onto ASD particles, which imparted enhanced micromeritic properties, namely, reduced agglomeration and improved powder flowability. ASD particles were stored at 40 °C and a selected relative humidity level between 31 and 75%. Crystallization was monitored by X-ray powder diffraction and scanning electron microscopy (SEM) up to 48 weeks. Crystallization was observable by SEM within 1–2 weeks for all uncoated samples. After ALC, crystallization was effectively delayed or completely inhibited in some systems up to 48 weeks. The delay achieved was demonstrated regardless of polymer hygroscopicity, presence or absence of hydroxyl functional groups in drugs and/or polymers, particle size, or coating properties. The crystallization inhibition effect is attributed primarily to decreased surface molecular mobility. ALC has the potential to be a scalable strategy to enhance the physical stability of ASD systems to enable high drug loading and enhanced robustness to temperature or relative humidity excursions.

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Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Atomic Layer Coating to Inhibit Surface Crystallization of Amorphous Pharmaceutical Powders

Moseson

Benson

Nguyen

et al. 2022

ACS Appl. Mater. Interfaces

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“…EC are designed to save the active ingredients of the tablets from dissolution and digestion within stomach under high acidic pH conditions [ 73 ]. Previous studies have shown that the Methacrylic acid—ethyl acrylate copolymer protects the dissolution of active ingredients under acidic conditions [ 74 , 75 ].…”

Section: Discussionmentioning

confidence: 99%

Enteric-Coated Cologrit Tablet Exhibit Robust Anti-Inflammatory Response in Ulcerative Colitis-like In-Vitro Models by Attuning NFκB-Centric Signaling Axis

et al. 2022

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Ulcerative colitis (UC) is an inflammatory bowel disease that affects the patients’ colorectal area culminating in an inflamed ‘leaky gut.’ The majority of UC treatments only provide temporary respite leading to its relapse. Therefore, this study investigated the efficacy of the enteric-coated ‘Cologrit’ (EC) tablet in alleviating UC-like inflammation. Cologrit is formulated using polyherbal extracts that have anti-inflammatory qualities according to ancient Ayurveda scriptures. Phytochemical profiling revealed the presence of gallic acid, rutin, ellagic acid, and imperatorin in Cologrit formulation. Cologrit treatment decreased inflammation in LPS-induced transformed THP-1 macrophages, and TNF-α-stimulated human colorectal (HT-29) cells through the modulation of NFκB activity, IL-6 production, and NFκB, IL-1β, IL-8, and CXCL5 mRNA expression levels. Cologrit also lessened human monocytic (U937) cell adhesion to HT29 cells. Methacrylic acid-ethylacrylate copolymer-coating of the enteric Cologrit tablets (EC) supported their dissolution, and the release of phytochemicals in the small intestine pH 7.0 environment in a simulated gastrointestinal digestion model. Small intestine EC digestae effectively abridged dextran sodium sulfate (2.5% w/v)-induced cell viability loss and oxidative stress in human colon epithelial Caco-2 cells. In conclusion, the enteric-coated Cologrit tablets demonstrated good small intestine-specific phytochemical delivery capability, and decreased UC-like inflammation, and oxidative stress through the regulation of TNF-α/NFκB/IL6 signaling axis.

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“…To address those challenges we introduce, to the best of our knowledge for the first time, an ultra-highresolution (UHR-) OCT system based on a novel robust and compact light source, which is potentially suitable even for future industrial applications. 1 We assess and compare the performance of the UHR-OCT system to a pharmaceutical OCT system and investigate the advantages of the UHR-OCT to resolve defects and thin coating layers in pellets, which were not previously visible with classical approaches. To cover a broad range of layer thicknesses, product-appearances, and coatings, we investigated three different pellet products with single-and multi-layered coating structures.…”

Section: Introductionmentioning

confidence: 99%

Investigation of thin pharmaceutical coatings with ultra-high-resolution optical coherence tomography

Haindl,

Kern,

Deng

et al. 2023

Optical Coherence Imaging Techniques and Imaging in Scattering Media V

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Optical Coherence Tomography (OCT) recently attracted attention for the quality control of pharmaceutical film-coatings. Current research focuses on single-layered tablet coatings with layer thicknesses between 50 and 100 µm and production end-point detection using commercial systems available for such applications. Modern multi-particulate dosage forms, particularly interesting for pediatric and personalized medicine, show coating layer thicknesses of 20 µm and below, pushing the limits of commercial pharmaceutical industrial OCT systems, which are namely their spatial and temporal resolutions. We present a novel ultra-high-resolution (UHR-) OCT prototype investigating merits and constraints of the technology based on imaging and semi-automatic layer thickness segmentation and quantification of exemplary multi-particulate dosage forms with different layer structures and layer thicknesses in a range from 7 to 50 µm. The UHR-OCT system allows, for the first time, imaging of morphological features and defects within thin pharmaceutical coatings, accurate film thickness measurements and the quantitative analyses of coating layer variability. Our investigation showcases that UHR-OCT can be the next logical and necessary step to advance quality control in pharmaceutical settings.

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Ascertain a minimum coating thickness for acid protection of enteric coatings by means of optical coherence tomography

Cited by 19 publications

References 35 publications

Atomic Layer Coating to Inhibit Surface Crystallization of Amorphous Pharmaceutical Powders

Atomic Layer Coating to Inhibit Surface Crystallization of Amorphous Pharmaceutical Powders

Enteric-Coated Cologrit Tablet Exhibit Robust Anti-Inflammatory Response in Ulcerative Colitis-like In-Vitro Models by Attuning NFκB-Centric Signaling Axis

Investigation of thin pharmaceutical coatings with ultra-high-resolution optical coherence tomography

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