Background/Objectives: Omeprazole undergoes degradation in acidic conditions, which makes it unstable in low pHs found in the gastric environment. The vast majority of already marketed omeprazole formulations use enteric polymer coatings to protect the drug from exposure to acidic pH in the stomach, allowing for drug release in the small intestine where the pH is higher. This study aimed to explore the technical aspects of using stomach acid neutralizers as an alternative to polymeric coatings for omeprazole. Methods: After evaluating various neutralizers, magnesium oxide and sodium bicarbonate were chosen to be incorporated into capsules containing omeprazole, which then underwent in vitro dissolution testing to assess their ability to maintain optimal pH levels and ensure appropriate dissolution kinetics. Hygroscopicity and chemical stability of the selected formulation were tested to prove pharmaceutical quality of the product. An in vivo pharmacokinetic study was conducted to demonstrate the efficacy of the omeprazole-sodium bicarbonate formulation in providing faster absorption in humans. Results: Sodium bicarbonate was selected as the most suitable antacid for ensuring omeprazole stabilization. Its quantity was optimized to effectively neutralize stomach acid, facilitating the rapid release and absorption of omeprazole. In vitro studies demonstrated the ability of the formulation to neutralize gastric acid within five minutes. In vivo studies indicated that maximum concentrations of omeprazole were achieved within half an hour. The product met the requirements of pharmaceutical quality. Conclusions: An easily manufacturable, fast-absorbing oral formulation was developed as an alternative to enteric-coated omeprazole.
- Publication type
- Journal Article MeSH
The properties of dry-coated paracetamol particles (fast-dissolving model drug) with carnauba wax particles as the coating agent (dissolution retardant) were investigated. Raman mapping technique was used to non-destructively examine the thickness and homogeneity of coated particles. The results showed that the wax existed in two forms on the surface of the paracetamol particles, forming a porous coating layer: i) whole wax particles on the surface of paracetamol and glued together with other wax surface particles, and ii) deformed wax particles spread on the surface. Regardless of the final particle size fraction (between 100 and 800 μm), the coating thickness had high variability, with average thickness of 5.9 ± 4.2 μm. The ability of carnauba wax to decrease the dissolution rate of paracetamol was confirmed by dissolution of powder and tablet formulations. The dissolution was slower for larger coated particles. Tableting further reduced the dissolution rate, clearly indicating the impact of subsequent formulation processes on the final quality of the product.
- Publication type
- Journal Article MeSH
We have developed a novel simple method for effective preparing gold nanoparticles (AuNPs) intended for utilization in biomedicine. The method is based on gold sputtering into liquid poly(ethylene glycol) (PEG). The PEG was used as a basic biocompatible stabilizer of the AuNP colloid. In addition, two naturally occurring polysaccharides - Chitosan (Ch) and Methylcellulose (MC) - were separately diluted into the PEG base with the aims to enhance the yield of the sputtering without changing the sputtering parameters, and to further improve the stability and the biocompatibility of the colloid. The colloids were sterilized by steam, and their stability was measured before and after the sterilization process by dynamic light scattering and UV-Vis spectrophotometry. The results indicated a higher sputtering yield in the colloids containing the polysaccharides. The colloids were also characterized by atomic absorption spectroscopy (AAS) to reveal the composition of the prepared nanoparticles by transmission electron microscopy (TEM) to visualize the nanoparticles and to evaluate their size and clustering, and by rheometry to estimate the viscosity of the colloids. The zeta-potential of the AuNPs was also determined as an important parameter indicating the stability and the biocompatibility of the colloid. In addition, in vitro tests of antimicrobial activity and cytotoxicity were carried out to estimate the biological activity and the biocompatibility of the colloids. Antimicrobial tests were performed by a drip test on two bacterial strains - Gram-positive Staphylococcus epidermidis and Gram-negative Escherichia coli. AuNP with chitosan proved to possess the highest antibacterial activity, especially towards the Gram-positive S. epidermidis. In vitro tests on eukaryotic cells, i.e. human osteoblastic cell line SAOS-2 and primary normal human dermal fibroblasts (NHDF), were performed after a 7-day cultivation to determine the effect and the toxic dose of the colloids on human cells. The studied colloid concentrations were in the range from 0.6 μg/ml to 6 μg/ml. Toxicity of the colloids started to reappear at a concentration of 4.5 μg/ml, especially with chitosan in the colloid, where the colloid with a concentration of 6 μg/ml proved to be the most toxic, especially towards the SAOS-2 cell line. However, the PEG and PEG-MC containing colloids proved to be relatively non-toxic, even at the highest concentration, but with a slowly decreasing tendency of the cell metabolic activity.
- MeSH
- Anti-Bacterial Agents chemistry pharmacology MeSH
- Cell Line MeSH
- Chitosan chemistry MeSH
- Dynamic Light Scattering MeSH
- Escherichia coli drug effects MeSH
- Colloids chemistry MeSH
- Metal Nanoparticles chemistry MeSH
- Humans MeSH
- Methylcellulose chemistry MeSH
- Polysaccharides chemistry MeSH
- Drug Stability MeSH
- Staphylococcus epidermidis drug effects MeSH
- Sterilization MeSH
- Particle Size MeSH
- Gold chemistry pharmacology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
In the present work, non-woven, non-regenerated cellulose wound dressing was subjected to in situ silver (Ag) deposition in the form of silver chloride (AgCl) under various reaction conditions. The studied reaction parameters were as follows: time, temperature, and reactants´ concentration. AgCl was bound on the cellulose via two-step process. Firstly, the silver ions (Ag+) were attracted to cellulose in the solution of silver nitrate (AgNO3). Secondly, Ag+ were precipitated directly on the cellulose by immersing the samples into the solution of sodium chloride (NaCl). The prepared samples were examined on the amount of bound and released Ag, and the release was studied both in water and in simulated body fluids. The reaction parameters significantly affected the amount of bound and released Ag, the difference of released Ag was as high as 75%. The key parameter in the process was reactants´ concentration. Non-regenerated cellulose modified with AgCl was antibacterially active.
Cellulose-based biomaterials are safe and ordinarily used in human medicine. Owing to its properties, cellulose is still in the biomaterial research spotlight, mainly in wound dressing area. The review brings an overview of chemical and physical means of cellulose modification that have been done so far, particularly to improve material properties and to introduce antibacterial properties. The most frequent antibacterial finishing of cellulose-based materials is the modification with silver that is effective against broad spectrum of bacteria species and has low risk of resistance development. A special subchapter is therefore dedicated to the antibacterial effect of silver.
- Keywords
- fyzikální modifikace, chemická modifikace,
- MeSH
- Anti-Bacterial Agents classification therapeutic use MeSH
- Biocompatible Materials * classification MeSH
- Cellulose * analogs & derivatives chemistry classification MeSH
- Humans MeSH
- Oxidation-Reduction MeSH
- Plasma Gases classification MeSH
- Wounds and Injuries nursing MeSH
- Regenerative Medicine MeSH
- Silver Compounds therapeutic use MeSH
- Silver therapeutic use MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
In this research, influence of storage conditions on properties of oxidized cellulose was studied with respect to its haemostatic function. The aim was to examine changes of the properties of oxidized cellulose stored properly and that stored at laboratory conditions for 2 years. We studied surface morphology and chemical composition, as well as absorption of the simulated body fluid, behaviour in aqueous environment via potentiometric measurement of pH, and antimicrobial activity in vitro on the S. epidermidis bacteria. It was found out that the material properties of oxidized cellulose did not deteriorate. Higher absorption of simulated body fluid, lower pH in water and simulated body fluid represented positive changes with respect to the haemostatic function. Due to the acidic nature of the mate-rial, degraded oxidized cellulose preserved its antibacterial properties.
- MeSH
- Anti-Bacterial Agents analysis MeSH
- Cellulose, Oxidized * analysis MeSH
- Microscopy, Electron methods MeSH
- Photoelectron Spectroscopy methods MeSH
- Hemostatics analysis MeSH
- Quality Control MeSH
- Drug Storage MeSH
- Environmental Exposure prevention & control MeSH
- Publication type
- Clinical Study MeSH
- Research Support, Non-U.S. Gov't MeSH
