Avanafil Liposomes as Transdermal Drug Delivery for Erectile Dysfunction Treatment: Preparation, Characterization, and In vitro, Ex vivo and In vivo Studies

Purpose: To formulate avanafil, a recently approved phosphodiesterase-5 enzyme inhibitor, in liposomal form for enhanced transdermal permeation and bioavailabilityMethods: Two preparation procedures were employed, leading to the formation of multilamellar vesicles (MLVs) and reverse-phase evaporation unilamellar vesicles (ULVs). The effects of the preparation method and lipid content on the encapsulation efficiency and particle size were studied. Studies assessing the stability, in vitro release, ex vivo permeation and in vivo bioavailability were also conducted in rats.Results: The preparation of avanafil liposomes as MLVs, the addition of cholesterol, and the use of more rigid phospholipids all increased the avanafil encapsulation efficiency within the liposomes (95.61 %). The stability studies revealed that the liposomes prepared using phospholipids with higher transition temperatures (dipalmitoyl-L-α-phospatidylcholine) were significantly more stable for a longer period of time after storage at 25 ± 0.5 ˚C and 60 ± 5 % relative humidity for a period of 2 months (p < 0.05). In vivo pharmacokinetic results from rats showed a significant increase in the bioavailability of avanafil from transdermal liposomal formulations of up to 7-fold (p < 0.05) compared to the topical drug suspension.Conclusion: The developed avanafil liposomes represent a promising transdermal drug delivery system for the treatment of erectile dysfunction.Keywords: Avanafil, Liposomes, Entrapment efficiency, Dipalmitoyl-L-α- hospatidylcholine, Erectile dysfunctio

Design and formulation of a topical hydrogel integrating lemongrass-loaded nanosponges with an enhanced antifungal effect: in vitro/in vivo evaluation

Hibah M Aldawsari,1 Shaimaa M Badr-Eldin,1,2 Gihan S Labib,1,3 Amal H El-Kamel3 1Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia; 2Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt; 3Department of Pharmaceutics, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt Abstract: Lemongrass oil (LGO) is a volatile oil extracted from the leaves of Cymbopogon citratus that has become one of the most important natural oils in the pharmaceutical industry because of its diverse pharmacologic and clinical effects. However, LGO suffers from low aqueous solubility, which could lead to a reduced effect. Moreover, the instability of its major active constituent, citral, could lead to volatilization, reaction with other formulation ingredients, and consequently, skin irritation. To surmount these problems, this research aims to formulate lemongrass-loaded ethyl cellulose nanosponges with a topical hydrogel with an enhanced antifungal effect and decreased irritation. The minimal inhibitory concentration and minimal fungicidal concentration of LGO against Candida albicans strain ATC 100231, determined using the broth macrodilution method, were found to be 2 and 8 µL/mL, respectively. The emulsion solvent evaporation technique was used for the preparation of the nanosponges. The nanosponge dispersions were then integrated into carbopol hydrogels (0.4%). Nine formulations were prepared based on a 32 full factorial design employing the ethyl cellulose:polyvinyl alcohol ratio and stirring rate as independent variables. The prepared formulations were evaluated for particle size, citral content, and in vitro release. Results revealed that all the nanosponge dispersions were nanosized, with satisfactory citral content and sustained release profiles. Statistical analysis revealed that both ethyl cellulose:polyvinyl alcohol ratio and stirring rate have significant effects on particle size and percentage released after 6 hours; however, the effect of the stirring rate was more prominent on both responses. The selected hydrogel formulation, F9, was subjected to surface morphological investigations, using scanning and transmission electron microscopy, where results showed that the nanosponges possess a spherical uniform shape with a spongy structure, the integrity of which was not affected by integration into the hydrogel. Furthermore, the selected formulation, F9, was tested for skin irritation and antifungal activity against C. albicans, where results confirmed the nonirritancy and the effective antifungal activity of the prepared hydrogel. Keywords: Cymbopogon Citratus, Citral, Volatile oil, factorial design, ethyl cellulose, Candida albicans, ge

Optimized Nanostructured Lipid Carriers Integrated into in situ Nasal Gel for Enhancing Brain Delivery of Flibanserin [Retraction]

Fahmy UA, Ahmed OAA, Badr-Eldin SM, et al. Int J Nanomedicine. 2020;15:5253-5264. The Editor and Publisher of International Journal of Nanomedicine are retracting the above published article. An investigation by the Publisher, found overlap in images from Figure 6 of the published article above and the images from Figure 6 of the following published article: Ahmed OAA, Fahmy UA, Badr-Eldin SM, et al. Application of Nanopharmaceutics for Flibanserin Brain Delivery Augmentation Via the Nasal Route. Nanomaterials. 2020; 10(7):1270 (https://doi.org/10.3390/nano10071270). Specifically, this included: From the published article above, Figure 6B, plain in situ gel group, and 6D, optimized FLB-NLC in situ gel group, are the same images as Figure 6D, rats treated with optimized FLB-TRF hydrogel (gp4) and 6C, rats treated with raw FLB loaded in hydrogel (gp3), respectively, from Ahmed et al, 2020. Furthermore, the images in Figure 6 of the published article above are derived from the same image but used to describe different results. Specifically, this included: From the published article above, Figure 6A, Control untreated group; 6B, plain in situ gel group; 6C, raw FLB loaded in situ gel group and 6D, optimized FLB-NLC in situ gel group, are all derived from the same image but used to describe different results. The authors cooperated with the investigation and provided data and associated documents concerning the histopathological experiments from the reported study. However, the Editor and Publisher determined that the evidence provided did not establish sufficient justification for the duplication. Therefore, the Editor and Publisher are retracting the article. The authors have agreed to retract the article and have informed the Publisher that the first author, Usama A Fahmy, takes responsibility for the error which occurred. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as “Retracted”