Anti Pneumococcal Activity of Azithromycin-Eudragit RS100 Nano-Formulations.

Purpose: Bacterial pneumonia is a common lung infection caused by different types of bacteria. Azithromycin (AZI), an azalide antibiotic, is widely used to manage pneumococcal infections. Studies have shown that antibiotics in nanocarriers may lead to increased antibacterial activity and reduced toxicity. The aim of this work was to valuate in vitro antibacterial performance azithromycin-Eudragit RS100 nano-formulations against Streptococcus pneumoniae and Staphylococcus aureus. Methods: AZI-Eudragit RS100 nanoparticles were prepared via electrospinning technique and the in vitro antibacterial performance against S. pneumoniae and S. aureus were assessed using agar dilution method. Results: Nanofibers in the sizes about 100-300 nm in diameter and micro scale in length and nanobeads in the range of 100-500 nm were achieved. The Minimum Inhibitory Concentrations (MIC) showed an enhancement in the antimicrobial effect of AZI-Eudragit RS100 nanofibers (40 µg/ml) compare to untreated AZI solution (>160 µg/ml) against S. pneumonia. The MIC value for AZI-Eudragit RS100 nanofibers against S. aureus was >128 µg/ml, same as that of the untreated AZI solution. Conclusion: The enhanced efficiency of AZI in nanofibers could be related to the more adsorption opportunity of nanofibers to S. pneumonia capsulated cell wall which provides an antibiotic depot on the bacterial surface compared to S. aureus. AZI-Eudragit RS100 nanofibers with enhanced antimicrobial effect against S. pneumonia can be considered as a candidate for in vivo evaluations in antibiotic therapy of Pneumococcal infections.

Methylprednisolone acetate-Eudragit® RS100 electrospuns: Preparation and physicochemical characterization.

The aim of the present study was to formulate methylprednisolone acetate -Eudragit(®) RS100 nanofibers and nanobeads by the electrospinning method. The physicochemical characteristics of the prepared electrospuns were assessed as well. The particle size and morphology were evaluated using scanning electron microscopy. The crystallinity of the drug in the nanofibers and nanobeads obtained was also studied by X-ray crystallography and differential scanning calorimetry (DSC) thermograms. In addition, FT-IR spectroscopy was applied to investigate any possible chemical interaction between the drug and carrier during the preparation process. The drug release kinetics were considered, to predict the release mechanism. Increasing the concentration of the injected solution resulted in the production of more nanofibers and less nanobeads, with the particle size ranging from 100 to 500 nm. The drug crystallinity was decreased during the electrospinning process; however, no interaction between drug and polymer was observed. The electrospuns showed faster drug release pattern compared to the pure drug. The release data were best fitted to the Weibull model, in which the corresponding shape factor values of the model were less than 0.75 indicating the diffusion mechanism of drug release. In conclusion, electrospinning could be considered as a simple and cost effective method for fabricating the drug: polymer nanofibers and nanobeads.

Triamcinolone acetonide-Eudragit(®) RS100 nanofibers and nanobeads: Morphological and physicochemical characterization.

CONTEXT AND OBJECTIVE: The aim of the present research was to fabricate triamcinolone acetonide (TA)-Eudragit(®) RS100 nanostructures using the electrospraying method. MATERIALS AND METHODS: The physicochemical properties of the electrosprayed formulations as well as drug release patterns were assessed. The particle size and morphology were evaluated using scanning electron microscopy. X-ray crystallography and differential scanning calorimetry were also conducted to investigate the crystallinity and polymorphic alterations of the drug in the formulations. Probable chemical interactions between the drug and the carrier during the preparation process were analyzed using FT-IR spectroscopy. The drug release kinetic was also considered to predict the release mechanism. RESULTS AND DISCUSSION: Increasing the concentration of injected polymer solution resulted in the formation of more fibers and fewer beads, with the particle diameter ranging from 60 nm to a few micrometers based on the drug: polymer ratio. The drug crystallinity was notably decreased during the electrospraying process; however, no interaction between drug and polymer was detected. The electrosprayed formulations with 1:10 drug: polymer ratio showed an almost similar drug release rate compared to the pure drug, while those with 1:5 ratio revealed slower release profiles. The release data were best fitted to the Weibull model, so that the corresponding shape factor values of the Weibull model were less than 0.75, indicating the diffusion controlled release mechanism. CONCLUSION: Our findings revealed that TA loaded Eudragit(®) RS100 nanofibers and nanobeads were properly prepared by the electrospraying method, which is a simple, surfactant-free and cost effective technique for producing drug: polymer nanostructures.

Application of electrospraying as a one-step method for the fabrication of triamcinolone acetonide-PLGA nanofibers and nanobeads.

The aim of the present project was to prepare triamcinolone acetonide nanofibers and nanobeads with prolonged anti-inflammatory activity. Triamcinolone acetonide-loaded PLGA nanoformulations were prepared by electrospraying method. The physicochemical and morphological properties of the fabricated nanoparticles were characterized as well. In vitro drug release of the prepared formulations was also studied. Differential scanning calorimetry and X-ray powder diffractometery showed that drug crystallinity was notably decreased during the electrospraying process. In vitro dissolution tests verified that the pure drug and physical mixtures had faster drug release pattern compared to the nanoformulations. Electrosprayed samples with the drug:polymer ratio of 1:10 revealed slower release profiles compared to those with a 1:5 ratio. Results obtained from SEM images of the prepared formulations indicated that polymer solution concentration was the critical parameter in the formation of fibers or beads; so that, fiber formation was increased proportionally with increasing polymer concentration. Moreover, the size of obtained nanostructures was also increased in order of polymer concentrations. As a final point, electrosprayed triamcinolone-loaded biodegradable micro/nanofibers and nanobeads with modified physicochemical characteristics and sustained drug release profiles were successfully prepared via simple, one-step and cost effective electrospraying technique.