Plant-derived 5 α-reductase inhibitors, such as β-sitosterol and phytosterol glycosides, have been used to treat androgenic alopecia, but their oral absolute bioavailability is poor. This study aimed to develop a transdermal drug delivery system of β-sitosterol (BS) using a nanostructured lipid carrier (NLC) incorporated into polymeric microneedles (MN). Using a high-speed homogenization method, NLC was formulated variables were optimized by Box-Behnken statistical design. The optimized formulation of BS-loaded NLCs was incorporated into the chitosan-based MNs to prepare NLC-loaded polymeric MNs (NLC-MNs) and evaluated using testosterone induced alopecia rats. The cumulative amount of β-sitosterol associated with NLC- MN which penetrated the rat skin in-vitro was 3612.27 ± 120.81 μg/cm², while from the NLC preparation was 2402.35 ± 162.5 μg/cm². The steady state flux (J_ss) of NLC-MN was significantly higher than that of the optimized NLC formulation (P < 0.05). Anagen/telogen ratio was significantly affected by NLC and NLC-MN, which was 2.22 ± 0.34, 1.24 ± 0.18 respectively compared to 0.26 ± 0.08 for animal group treated with testosterone. The reversal of androgen-induced hair loss in animals treated with β-sitosterol was a sign of hair follicle dominance in the anagenic growth phase. However, NLC–MN delivery system has shown significant enhancement of hair growth in rats. From these experimental data, it can be concluded that NLC incorporated MN transdermal system have potential in effective treatment of androgenic alopecia. Graphical Abstract

Objectives: The study aimed to prepare carbamazepine in solid lipid nanoparticle form (CBZ-SLN) in order to enhance its anticonvulsant effect. Method: Eight formulations of CBZ-SLNs were prepared by homogenization and ultra-sonication techniques. Results: The prepared CBZ-SLN showed a high entrapment efficiency% (39.66 ± 2.42%–71.91 ± 1.21%), a small particle size (45.11 ± 6.72–760.7 ± 5.25 nm), and a negative zeta potential (from −21.5 ± 1.02 to −38.4 ± 1.32 mv). The in vitro release study showed the slow release of CBZ from SLNs compared to CBZ aqueous dispersion (p < 0.05). The infrared spectroscopy and the thermal analysis revealed the compatibility of the drug with other ingredients and the presence of drug in the more soluble amorphous estate, respectively. The in vivo study on mice revealed that the CBZ-SLN had a higher anticonvulsant efficacy than CBZ aqueous dispersion after a lethal and chronic dose of pentylenetetrazole (PTZ) (p < 0.05). The histopathological examination of the hippocampus revealed a decrease in the percentage of degeneration in mice treated with the CBZ-SLN compared to the PTZ and CBZ groups. Conclusion: CBZ can be formulated as SLN with higher anticonvulsant activity than free CBZ aqueous dispersion.

Sitagliptin (SGN) is an antidiabetic drug used for treatment of diabetes mellitus type II. The objectives of this study were to formulate SGN in form of thiolated chitosan (TC) nanoparticles to enhance the mucoadhesion properties of SGN to the gastrointestinal tract, prolong drug release, decrease side effects, and enhance patient compliance. Seventeen batches of SGN-TC nanoparticles were designed by Box-Behnken design and prepared using the ionic gelation method using tripolyphosphate (TPP) as crosslinking agent. The prepared formulations were evaluated for particle size, entrapment efficiency %, and in vitro drug release. Based on the results of optimization, three formulations (F1–F3) were prepared with different drug polymer ratios (1:1, 1:2, and 1:3). The mucoadhesion study and in vivo hypoglycemic activity of three formulations were evaluated in comparison to free SGN in streptozotocin (STZ)-induced diabetic rats. The seventeen SGN-TC nanoparticles showed small particle sizes, high entrapment efficiency, and prolonged drug release. The concentration of TC polymers had highest effect on these responses. The percentage of SGN–TC nanoparticles adhered to tissue was increased and the release was prolonged as the concentration of TC polymer increased (F3 > F2 > F1). The hypoglycemic effect of SGN-TC nanoparticles was significantly higher than resulted by free SGN. It was concluded that TC nanoparticles had the ability to enhance the mucoadhesion properties of SGN and prolong the drug release. SGN-TC nanoparticles significantly reduced plasma glucose levels compared to free SGN in STZ-induced diabetic rats.