In Vitro and In Vivo Evaluation of Magnetic Floating Dosage Form by Alternating Current Biosusceptometry.

Floating controlled systems seek to extend the gastric retention time (GRT) of solid pharmaceutical forms by sustaining buoyancy in the stomach without affecting gastric emptying rates. This investigation aimed to evaluate a magnetic floating drug delivery system (MFDDS) under diverse physiological conditions (pressure and viscosity) using an Alternating Current Biosusceptometry (ACB) system by conducting assessments in vitro and in vivo. For in vitro experiments, MFDDSs were placed under different pressures (760, 910, and 1060 mmHg) and viscosities (1, 50, 120, and 320 mPa·s) for evaluation of floating lag time (FLT). For in vivo experiments, eight healthy volunteers participated in two phases (fasting and fed) for gastric parameters (GRT, FLT, and OCTT-orocaecal transit time) assessment, employing the ACB system. The results indicated that pressure, viscosity, and FLT were directly proportional in the in vitro assay; in addition, increases in the OCTT (fasting = 241.9 ± 18.7; fed = 300 ± 46.4), GRT (fasting = 139.4 ± 25.3; fed = 190.2 ± 47.7), and FLT (fasting = 73.1 ± 16.9; fed = 107.5 ± 29.8) were detected in vivo. Our study emphasizes that the ACB system is a valuable technique, and it is capable of tracking and imaging MFDDS in in vitro and in vivo experiments.

Non-invasive biomagnetic assessment of gastrointestinal motility in a loperamide-induced constipation model

Constipation is a disorder of the gastrointestinal (GI) and some of the main etiological mechanisms are directly related to changes in GI physiology. The capacity to carry out paired assessments and measure GI parameters under the influence of constipation is a relevant point in selecting a suitable methodology. We aimed to perform a non-invasive investigation of gastrointestinal motility in constipated rats using the alternating current biosusceptometry system (ACB). The animals were split into two groups: the pre-induction stage (CONTROL) and post-induction loperamide stage (LOP). We assessed GI motility parameters using the ACB system. Colon morphometric and immunohistochemical analyses were performed for biomarkers (C-kit) for interstitial cells of Cajal (ICC). Our results showed a significant increase in gastrointestinal transit in the LOP group in addition to a reduction in the dominant frequency of gastric contraction and an arrhythmic profile. A change in colonic contractility profiles was observed, indicating colonic dysmotility in the LOP group. We found a reduction in the number of biomarkers for intestinal cells of Cajal (ICC) in the LOP group. The ACB system can evaluate transit irregularities and their degrees of severity, while also supporting research into novel, safer, and more efficient treatments for constipation.

Pharmacomagnetography assessment of the prokinetic effect on metronidazole absorption.

OBJECTIVES: This study aimed to evaluate the effects of prucalopride, a prokinetic agent that acts as a potent serotonin agonist of 5-HT4 receptors, on gastric emptying and small bowel transit and assess its impact on the absorption of metronidazole. METHODS: Six healthy volunteers, three men and three women, aged between 20 and 27 years, with a body weight ranging from 50 to 80 kg, were enrolled in this study. The pharmacokinetics and gastrointestinal transit parameters were evaluated simultaneously through pharmacomagnetography assessment, combining alternating current biosusceptometry and blood analysis. KEY FINDINGS: The results showed that prucalopride enhances gastric emptying and small bowel transit when administered orally and significantly impacts the rate of metronidazole absorption, leading to enhanced bioavailability and rapid therapeutic response. CONCLUSION: Pharmacomagnetography assessment allows simultaneous tracking of transit by images and is a valuable method for analysing drug absorption using multiple instruments.

Corona protein impacts on alternating current biosusceptometry signal and circulation times of differently coated MnFe2O4 nanoparticles.

Background: We evaluated the impacts of corona protein (CP) formation on the alternating current biosusceptometry (ACB) signal intensity and in vivo circulation times of three differently coated magnetic nanoparticles (MNP): bare, citrate-coated and bovine serum albumin-coated MNPs. Methods: We employed the ACB system, gel electrophoresis and mass spectrometry analysis. Results: Higher CP formation led to a greater reduction in the in vitro ACB signal intensity and circulation time. We found fewer proteins forming the CP for the bovine serum albumin-coated MNPs, which presented the highest circulation time in vivo among the MNPs studied. Conclusion: These data showed better biocompatibility, stability and magnetic signal uniformity in biological media for bovine serum albumin-coated MNPs than for citrate-coated MNPs and bare MNPs.