An in vitro dissolution model, the so-called EyeFlowCell (EFC), was developed to test intravitreal dosage forms, simulating parameters such as the gel-like consistency of the vitreous body. The developed model consists of a stereolithography 3D-printed flow-through cell with a polyacrylamide (PAA) gel as its core. This gel needed to be coated with an agarose sheath because of its low viscosity. Drug release from hydroxypropyl methylcellulose-based implants containing either triamcinolone acetonide or fluorescein sodium was studied in the EFC using a schematic eye movement by the EyeMovementSystem (EyeMoS). For comparison, studies were performed in USP apparatus 4 and USP apparatus 7. Significantly slower drug release was observed in the PAA gel for both model drugs compared with the compendial methods. Drug release from fluorescein sodium-containing model implants was completed after 40 min in USP apparatus 4, whereas drug release in the gel-based EFC lasted 72 h. Drug release from triamcinolone acetonide-containing model implants was completed after 35 min in USP apparatus 4 and after 150 min in USP apparatus 7, whereas this was delayed until 96 h in the EFC. These results suggest that compendial release methods may overestimate the drug release rate in the human vitreous body. Using a gel-based in vitro release system such as the EFC may better predict drug release.

The transit and distribution pattern of fluids in the small intestine is a key parameter for the dissolution and absorption of drugs. Although some information is known about the small intestinal water content after administration of fluid volumes and meals, the intestinal transit of orally ingested fluids and solutions has been barely investigated. The aim of this three-arm, cross-over, 9-subject human study was to investigate the transit of orally ingested water in the small intestine under fasting and postprandial conditions using MRI. To identify the ingested water, manganese gluconate, which can be identified with T1 weighted MRI sequences, was added as a marker. Using Horos (DICOM software), quantification of the distribution of Mn²⁺ ions in the gastrointestinal tract in fasted versus fed state (standard meal by FDA guidance and a light meal) was possible. The distribution and approximate wetted intestinal length was very similar in the fasting and postprandial states, suggesting rapid transport of water ingested after a meal through the chyme-filled small intestine in continuation of the "Magenstrasse" (stomach road). In some subjects, manganese gluconate reached deeper parts of the small intestine even more quickly in the postprandial state than in the fasting arm of the study. A deeper understanding of the behaviour of solutes in the gastrointestinal tract is fundamental to a mechanistic explanation for the kinetic interaction between food and drug intake (food effects).

Background: Current reference standards for measuring gastric emptying and motility are not considered optimal due to the time required, ionizing radiation, invasiveness, and spatial resolution. Purpose: To assess gastric motility using novel real‐time dynamic magnetic resonance imaging in combination with static measurements for gastric emptying and training of an automated deep‐learning‐based segmentation pipeline. Study Type: Prospective. Participants: The study included 36 healthy volunteers (20 female, mean 24 ± 3 years) and three patients with diagnosed Crohn's disease. Field Strength/Sequences: Participants ingested water to assess fasting motility and pineapple juice for the postprandial state. 3 T, 3D spoiled gradient echo (GRE) sequence and real‐time spoiled GRE. Assessment: Gastric emptying was measured by using the gastric volume, while motility was analyzed by tracking changes in the antrum's cross‐sectional area and applying Fast Fourier Transformation. Segmentations were performed using a trained semantic segmentation model. Statistical Tests: Linear Mixed Model with continuous dependent variables and fixed effects. Models included a random intercept for participants. Statistical significance was defined as p = 0.05. Results: The method enabled volumetric analysis of gastric content from 3D breath‐hold static acquisition and time‐resolved quantification of peristaltic parameters from real‐time FLASH2 imaging at high temporal resolution (here 6.24 fps). Water emptied rapidly and exponentially ( t _1/2 = 14.77 ± 10.55 min), while juice showed slower emptying ( t _1/2 = 64.24 ± 11.87 min). Contraction frequencies (fasted: 2.76 ± 0.43 cpm, fed: 2.89 ± 0.43 cpm) and velocities (fasted: 1.67 ± 0.38 mm/s, fed: 1.72 ± 0.37 mm/s) were within physiological ranges, with fasting conditions characterized by stronger occlusion compared to the fed. Measurements taken from three patients proved that the workflow could be used in a clinical context. Data Conclusion: Real‐time MRI with AI‐based analysis enabled quantitative assessment of gastric emptying and motility, revealing physiological peristaltic parameters and state‐dependent differences in occlusion. Evidence Level: 2. Technical Efficacy: Stage 1.

Fibers and yarns are part of everyday life. So far, fibers that are also used pharmaceutically have mainly been produced by electrospinning. The common use of spinning oils and the excipients they contain, in connection with production by melt extrusion, poses a regulatory challenge for pharmaceutically usable fibers. In this publication, a newly developed small-scale direct-spinning melt extrusion system is described, and the pharmaceutically useful polyvinyl filaments produced with it are characterized. The major parts of the system were newly developed or extensively modified and manufactured cost-effectively within a short time using rapid prototyping (3D printing) from various materials. For example, a stainless-steel spinneret was developed in a splice design for a table-top melt extrusion system that can be used in the pharmaceutical industry. The direct processing of the extruded fibers was made possible by a spinning system developed called Spinning-Rosi, which operates continuously and directly in the extrusion process and eliminates the need for spinning oils. In order to prevent instabilities in the product, further modifications were also made to the process, such as a the moisture encapsulation of the melt extrusion line at certain points, which resulted in a bubble-free extrudate with high tensile strength, even in a melt extrusion line without built-in venting.

Magnetic resonance imaging was used to investigate gastric emptying and small-intestinal distribution of a manganese-labeled 10.6% glucose solution in a randomized crossover study in 12 healthy volunteers under fasted and postprandial conditions after ingestion of a solid light meal. Following the ingestion of 240 mL of the test solution (100 kcal), manganese contrast appeared rapidly in the small intestine and reached distal regions within approximately 20 min in 9 out of 12 subjects, irrespective of the prandial state. Contacted small-intestinal length and small-intestinal distribution increased continuously during the early phase and plateaued thereafter, closely paralleling gastric emptying of the solution. While absolute intestinal contact lengths were lower under postprandial conditions, normalized spreading showed comparable temporal profiles in fasted and fed states, indicating similar distribution mechanisms. Although distribution was slower than previously reported for water, the spatial extent of intestinal spreading was largely preserved in the caloric vehicle. These findings demonstrate that the Magenstrasse and Darmstrasse are not restricted to non-caloric liquids but also govern the rapid luminal distribution of substances dissolved in caloric solutions, largely independent of prandial state, with relevant implications for oral drug delivery and food-effect interpretation.