Formulation and Characterization of Tobramycin-Chitosan Nanoparticles Coated with Zinc Oxide Nanoparticles

Herein we describe the preparation, characterization and the antibacterial effect of Tobramycin-chitosan nanoparticles (TOB-CS NPs) coated with zinc oxide nanoparticles (ZnO NPs). Four formulations of TOB-CS NPs (A-D) were prepared to study the effect of experimental variables on the NPs behavior. Two formulations of ZnO NPs were prepared using the solvothermal and the precipitation methods (ZnO₁ and ZnO₂), and then characterized. TOB-CS NPs (Formula d) was coated with the ZnO₁. Moreover, the antibacterial activity of TOB-CS NPs, ZnO NPs and the coated nanoparticles against S. aureus and E. coli was examined. Changing the variables in preparing TOB-CS NPs resulting in variabilities in sizes (297.6–1116.3 nm), charges (+8.29–+39.00 mV), entrapment (51.95–90.60%). Further, TOB release was sustained over four days. ZnO NPs have sizes of 47.44 and 394.4 nm and charges of −62.3 and 89.4 mV when prepared by solvothermal and precipitation technique, respectively. Coated TOB-CS NPs had a size of 342 nm, a charge of +4.39 and released 100 µg/ mL of the drug after four days. The antimicrobial activity of TOB-CS NPs was lower than free TOB against S. aureus and E. coli. The coated NPs showed higher antimicrobial effect in comparison to formula D and ZnO₁. In conclusion, coating TOB-CS NPs with ZnO NPs exhibited a great antibacterial effect that may be sustained for days.

Preparation and characterization of insulin chitosan-nanoparticles loaded in buccal films

Chitosan nanoparticles loaded with insulin (IN-CS-NPs) were prepared using ionic gelation method using sodium tripolyphophate as a crosslinker. Later the nanoparticles (NPs) were dispersed in buccal films. The physicochemical properties and the morphology of the nanoparticles were characterized. The stability and release of insulin from the NPs were investigated. Buccal films were prepared separately and their properties such as the weight, thickness, pH, and mucoadhesiveness were investigated. The best film was used to disperse IN-CS-NPs and the loaded film was characterized. The nanoparticles size, polydispersity index, zeta potential, entrapment efficacy, and the loading capacity were 325.07 ± 1.32 nm, 0.38 ± 0.03 and 8.41 ± 0.80 mV, and 73.27 and 18.03%, respectively. The weight and thickness of the loaded film with IN-CS-NPs were 23.0 ± 3.0 mg and 0.32 ± 0.04 mm, respectively and the mucoadhesive force was 2.3 ± 0.2 N. The drug was stable in the NPs and in the films for three months, and its release was controlled by the film and the nanoparticles. Finally, the films loaded with IN-CS-NPs were studied in vivo and were compared to the commercially available insulin. The films prepared in this work were found to decrease glucose level significantly in diabetic rats.

Gas chromatographic-mass spectrometric analysis of sunscreens and their effects on mice liver and kidney enzyme function

Background

Sunscreens are one of the most widely used products among cosmetics and personal care products. Recent studies have shown that some of sunscreen formulations may contain toxic, carcinogenic, or even nonallowed chemicals that may affect skin, cells, and hormones.

Materials and methods

This study aimed to develop and validate a method that allows the determination of sunscreen ingredients by gas chromatography-mass spectrometry (GC-MS). Analysis of original sunscreen products (n=5) from a licensed pharmacy and counterfeit sunscreen products (n=5) from local markets in Jordan was performed using GC-MS. pH stability of the sunscreen samples were also monitored under different storage temperatures. Topical application of sunscreens on mice skin was conducted to study their effects on liver and kidney enzymes' function.

Results

In terms of pH stability, there is a significant change in pH at different degrees of temperature between the products. Diethyl phthalate (DEP) was detected in two counterfeit products and was not mentioned on the ingredients' label. DEP was reported for its percutaneous absorption and systemic uptake in the literature. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased with a P<0.005 in some groups treated with original sunscreens under sun radiation. Creatinine showed a significant decrease in some groups treated with original and counterfeit sunscreens, while blood urea nitrogen (BUN) showed no differences.

Conclusion

This study presents a method that allows the scanning and profiling of sunscreen ingredients as well as investigates their stability, permeation, and toxicity. Profiling of sunscreen product, changing in pH stability, and analyzing kidney and liver enzymes' level would be of a great impact on products' safety and consumers' health.