Thymoquinone-Loaded Chitosan Nanoparticles as Natural Preservative Agent in Cosmetic Products

The current status of controversy regarding the use of certain preservatives in cosmetic products makes it necessary to seek new ecological alternatives that are free of adverse effects on users. In our study, the natural terpene thymoquinone was encapsulated in chitosan nanoparticles. The nanoparticles were characterized by DLS and TEM, showing a particle size of 20 nm. The chemical structure, thermal properties, and release profile of thymoquinone were evaluated and showed a successful stabilization and sustained release of terpenes. The antimicrobial properties of the nanoparticles were evaluated against typical microbial contaminants found in cosmetic products, showing high antimicrobial properties. Furthermore, natural moisturizing cream inoculated with the aforementioned microorganisms was formulated with thymoquinone-chitosan nanoparticles to evaluate the preservative efficiency, indicating its promising use as a preservative in cosmetics.

Successful Dendrimer and Liposome-Based Strategies to Solubilize an Antiproliferative Pyrazole Otherwise Not Clinically Applicable

Water-soluble formulations of the pyrazole derivative 3-(4-chlorophenyl)-5-(4-nitrophenylamino)-1H-pyrazole-4-carbonitrile (CR232), which were proven to have in vitro antiproliferative effects on different cancer cell lines, were prepared by two diverse nanotechnological approaches. Importantly, without using harmful organic solvents or additives potentially toxic to humans, CR232 was firstly entrapped in a biodegradable fifth-generation dendrimer containing lysine (G5K). CR232-G5K nanoparticles (CR232-G5K NPs) were obtained with high loading (DL%) and encapsulation efficiency (EE%), which showed a complex but quantitative release profile governed by Weibull kinetics. Secondly, starting from hydrogenated soy phosphatidylcholine and cholesterol, we prepared biocompatible CR232-loaded liposomes (CR232-SUVs), which displayed DL% and EE% values increasing with the increase in the lipids/CR232 ratio initially adopted and showed a constant prolonged release profile ruled by zero-order kinetics. When relevant, attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR) and nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM) and dynamic light scattering (DLS) experiments, as well as potentiometric titrations completed the characterization of the prepared NPs. CR232-G5K NPs were 2311-fold more water-soluble than the pristine CR232, and the CR232-SUVs with the highest DL% were 1764-fold more soluble than the untreated CR232, thus establishing the success of both our strategies.

How Does Fluid Flow Influence Drug Release from Drug Filled Implants?

Drug-filled implants (DFIs) have emerged as an innovative approach to control the delivery of drugs. These devices contain the drug within the structure of the implant itself and avoid the need to include additional drug carrier materials such as a polymers, which are often associated with inflammation and delayed healing/tissue regeneration at the implant site. One common feature of in vitro experiments to generate drug release profiles is stirring or agitation of the release medium. However, the influence of the resulting fluid flow on the rate of drug release from DFIs has yet to be quantified. In this paper we consider two DFIs, which although similar in shape and size, employ different strategies to control the release of drug: a porous pin with pores on the order of μm and a pin drilled with orifices of the order of mm. We develop a multiphysics mathematical model of drug release from these DFIs, subject to fluid flow induced through stirring and show that fluid flow greatly influences the drug release profile for the orifice pin, but that the porous pin drug release profile is relatively insensitive to flow. We demonstrate that drug release from the porous pin may adequately be described through a simplified radial 1D dissolution-diffusion model, while a 3D dissolution-advection-diffusion model is required to describe drug release from the orifice pin. A sensitivity analysis reveals that that the balance of reaction-advection-diffusion in terms of key nondimensional numbers governs the overall drug release. Our findings potentially have important implications in terms of devising the most relevant experimental protocol for quantifying drug release from DFIs.

Chitosan-clay nanocomposite as a drug delivery system of ibuprofen

Chitosan/montmorillonite nanocomposite films were prepared by the solvent evaporation method to immobilize the drug ibuprofen (IBU) and delay its release in a medium that simulates the environment of the gastrointestinal tract. The effects of montmorillonite, at different mass proportions (10, 20, and 50%), on the morphological and physical properties of the films were studied. The samples were characterized by X-ray diffraction (XRD), Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), degree of swelling, drug encapsulation, and drug release efficiency. According to the XRD it was evidenced that the incorporation of montmorillonite to chitosan led to the formation of nanocomposites of ordered morphology. The infrared spectra confirmed the good interaction between montmorillonite and chitosan by the formation of nanocomposites. This fact, which favored the imprisonment of the IBU, reduced the diffusion coefficient in the studied systems. The micrographs comproved the formation of dense and uniform films. The controlled release profile, especially for the nanocomposite with 10% clay mass, showed a slow drug release rate. The incorporation of montmorillonite at different proportions produced different morphologies, with good encapsulation efficiency and an adequate profile for the controlled release of the drug.

Effect of soft beverages on the in vitro dissolution of gastro-resistant tablets containing low dose Acetylsalicylic acid

The need for additional fluids for easy absorption is typical for elderly patients and those with dysphagia. Most often, these patients take their medication with a glass of orange juice or another liquid instead of a glass of water. We conducted a dissolution test with gastro-resistant tablets acetylsalicylic acid where different kind of orange juice or soft drink wеre added to the release medium. As a control, release medium - buffers 1.2, 4.5 and 6.8 were used. The released aspirin was determined after HPLC analysis. The obtained data were fitted to different kinetic models. The results of the dissolution test in medium buffers with added different beverage showed results similar to those obtained in pure buffer, where it is used an artificial sweetener and different, when sugar or glucose-fructose syrup was used to sweeten the beverage. The most significant change was observed in the release kinetics of the active substance.To exclude the possibility that the other beverage ingredients or excipients used to make the tablets affect the release profile of acetylsalicylic acid, we conducted a beverage-like dissolution test. Instead of a original beverage, we used water and sugar syrup, in a concentration that is declared on the label of the original beverages. The results obtained confirm that different sugar concentrations alter the release profile of acetylsalicylic acid from gastro resistant tablets when they are taken with a glass of sugar-containing beverage instead of a glass of water.

Fabrication of cefixime nanoparticles loaded films and their ex vivo antimicrobial effect on periodontitis patient’s saliva

Aim: This study was designed to prepare and evaluate cefixime-loaded nanoparticles containing low molecular weight chitosan films for the enhanced topical treatment of periodontitis. Methods: To fabricate the enhanced antimicrobial films, a nanoprecipitation method for cefixime nanoparticles followed by a solvent evaporation method for these nanoparticles loaded films were adopted in this study. Nine batches of nanoparticles (NPs) with different concentrations of ethyl cellulose and polyvinyl alcohol were prepared and evaluated. Furthermore, nine batches of optimized NPs loaded films with different concentrations of low molecular weight chitosan and glycerol were fabricated and evaluated. Optimized NPs loaded films were assessed for their antimicrobial activity against the periodontitis patient’s saliva samples. Results: The FT-IR spectroscopy and XRD study revealed that there was no interaction between the drug and all other excipients and the drug remained amorphous form in chitosan film. The SEM study revealed that the prepared NPs were spherical in shape and uniformly distributed in chitosan film. In vitro drug release study revealed the NPs have a sustained release profile up to 8 days and NPs loaded films have up to 11 days. The conventional marketed mouth wash shows a low inhibition zone of 5.70 ± 0.043 mm, whereas NPs loaded film shows a higher inhibition zone of 6.72 ± 0.063 mm against periodontal microorganisms present in the patient’s saliva. The stability study revealed that the optimized NPs loaded film shows no dramatic change in drug release profile and folding endurance after six months. Conclusion: This present study highlights the possible usage of cefixime NPs loaded films in enhanced periodontal treatment.

Three Component Composite Scaffolds Based on PCL, Hydroxyapatite, and L-Lysine Obtained in TIPS-SL: Bioactive Material for Bone Tissue Engineering

In this research, we describe the properties of three-component composite foam scaffolds based on poly(ε-caprolactone) (PCL) as a matrix and hydroxyapatite whiskers (HAP) and L-Lysine as fillers (PCL/HAP/Lys with wt% ratio 50/48/2). The scaffolds were prepared using a thermally induced phase separation technique supported by salt leaching (TIPS-SL). All materials were precisely characterized: porosity, density, water uptake, wettability, DSC, and TGA measurements and compression tests were carried out. The microstructure of the obtained scaffolds was analyzed via SEM. It was found that the PCL/HAP/Lys scaffold has a 45% higher Young’s modulus and better wettability compared to the PCL/HAP system. At the same time, the porosity of the system was ~90%. The osteoblast hFOB 1.19 cell response was also investigated in osteogenic conditions (39 °C) and the cytokine release profile of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α was determined. Modification of PCL scaffolds with HAP and L-Lysine significantly improved the proliferation of pre-osteoblasts cultured on such materials.