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Electrospinning has been one of the most attractive methods of fiber fabrication in the last century. A lot of studies have been conducted, especially in tissue engineering and drug delivery using electrospun fibers. Loading many different drugs and bioactive agents on or within these fibers potentiates the efficacy of such systems; however, there are still no commercial products with this technology available in the market. Various methods have been developed to improve the mechanical and physicochemical behavior of structures toward more controllable delivery systems in terms of time, place, or quantity of release. In this study, most frequent methods used for the fabrication of controlled release electrospun fibers have been reviewed. Although there are a lot of achievements in the fabrication of controlled release fibers, there are still many challenges to be solved to reach a qualified, reproducible system applicable in the pharmaceutical industry.

Background: Transdermal drug delivery has several advantages and has been vastly investigated over the last decades. Chemical enhancers improve the quantity of drug penetration through the skin. Objectives: In this study, some conventional solvents and surfactants were used as enhancers to promote dermal penetration of α-hydroxyacids (AHA) and hyaluronic acid (HA). Materials and Methods: A total of 42 different formulations containing AHA or HA as the active ingredient and a solvent or surfactant as the enhancer were prepared. The experiments for determination of transdermal absorption of AHA or HA for each formulation were performed using a diffusion cell and a slice of chicken skin as model at 32℃. After 1.5 or 12 hours, samples from the medium were collected and analyzed for AHA or HA concentration. Results: After 1.5 and 12 hours, the maximum permeated amount of AHA were 89.8 and 342.5 mg, respectively, which related to the formulations with liquid paraffin. After 1.5 and 12 hours, the maximum permeated amount of HA were 57.3 and 70.6 mg, respectively, which related to the formulations with glycerol. Conclusions:The most effective enhancer for AHA and HA were liquid paraffin and glycerol, respectively. The most effective surfactant for both AHA and HA was Tween 80. The effects of the enhancers were increased by prolonging the exposure time.

Objectives:Scientists have widely investigated the use of chemical enhancers to improve drug transport through the skin. In this study, ZnO and ZnO nanoparticles (ZnO-NPs) has been used as dermal absorption enhancers for Ibuprofen (IP). Methods:Seven different formulations containing IP, ZnO, or ZnO-NPs were prepared. Dermal absorption experiments were performed at 32°C using a diffusion cell containing phosphate buffer saline (pH 7.4) and a slice of chicken skin. Cumulative amounts of skin permeated IP, ZnO or ZnO-NPs were plotted over time.Results: After 60 minutes, 90, 8 and 81 mg ZnO, ZnO-NPs and IP were passed through the skin, respectively. This amount for IP was 105, 114, 131 and 183 mg in presence of 100 mg ZnO, 100 mg ZnONPs, 200 mg ZnO-NPs, and 500 mg ZnO-NPs, respectively. Maximum amount of not-permeated IP was seen for formulation 1 (IP without enhancer) and minimum notpermeated IP was seen for formulation 5 (IP with 500 mg ZnO-NPs as enhancer). Conclusion:ZnO and more strongly ZnO-NPs could act as enhancers for transdermal delivery of IP. Such effect was improved by increase in concentration of ZnO-NPs. Therefore, ZnO-NPs can be used as enhancer in dermal drug delivery formulations.

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Proficient antibiotic drug delivery plays a key role in treating infections. In this article we prepared an electrospun wound dressing which releases Tetracycline in a timed and dose controlled matter for one week. In order to fabricate a wound dressing which can release Tetracycline in a longer duration and at an effective therapeutic level we designed a bilayer electrospun patch made of polyvinyl alcohol (PVA), polycaprolacton (PCL), and coated the whole system with chitosan. The SEM micrograph showed the dependent relationship of the morphology of the nanofibers on the Tetracycline concentration, and the addition of PCL electrospun layer decreased the pore size and water uptake rate. However, it was found that coating PVA/PCL bilayered electrospun sheet with chitosan increased the water uptake rate, which is an important property in biomedical applications. According to the FTIR results, chemical composition of the scaffolds did not change during the fabrication process. Mechanical properties of the samples were assessed, and the results revealed that the chitosan coating improved the tensile strength of the electrospun layers. Furthermore, based on in vitro release tests, it was found that bilayered electrospun sheets coated with chitosan controlled drug release efficiently. In addition, the antibacterial tests performed in vitro showed stronger antibacterial activity on S. aureus cultures for PVA/PCL/Chitosan in comparison to uncoated samples.

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Objective:Transdermal route of drug administration has absorbed largeinterests for its many advantages. Several materials, mainly different solvents and surfactants, have been used as excipients to enhance the skin permeation of drugs.Nanoparticles (NPs) also have been proved to affect the permeations of substances.ZnO-NPs, widely used in topical products, have been investigated in this study in terms of their effects on permeations of different substances (excipients) and therefore permeations of active ingredients. Method: To determine the skin permeation of everysubstance, diffusion cell method and a cut of chicken skin were employed following by quantication of the substance concentration in the receiver medium after 1.5 hours. Results: The substances showed different permeations. The ZnO-NPs increased the permeation of each substance. In the absence and also in the presence of the ZnO-NPs, the mean amounts permeated were respectively belonged to hydrophobic solvents, hydrophilic solvents, oily solvents and surfactants. The ZnO-NPs increased the permeation ofhydrophobic solvents, oily solvents, hydrophilic solvents and surfactants, with 31.33, 24, 20.33 and 5.34%, respectively. Such increases, were not dependent on the molecular weight (MW) of the oily and hydrophobic solvents but were dependent on the MW of the hydrophilic solvents and the surfactants. Conclusion: The ZnO-NPs are suggested to be used for enhancing the skin permeations ofsolvents or surfactantsin topical productswhich potentially can improve absorption of active ingredients. Besides, such enhancing effect of the ZnO-NPs should be noticed in topical products where they may increase drug delivery dose and alsoincrease drug or excipient systemic toxicity.