Skin deposition and permeation of finasteridein vitro: effects of propylene glycol, ethanol and sodium lauryl sulfate

Mucosal Delivery of Cannabidiol: Influence of Vehicles and Enhancers

In this study, the mucosal permeation and deposition of cannabidiol (CBD) with neat and binary vehicles were investigated. Permeation experiments were performed using static diffusion cells coupled with fresh porcine esophageal mucosa. The CBD-vehicle solutions were applied at a fixed dose (~5 mg/cm²), and the corresponding permeation parameters were calculated. In neat vehicles, the permeation flux (J_ss) ranged from 0.89 ± 0.15 to 179.81 ± 23.46 µg·cm^-2·h^-1, while the CBD deposition ranged from 11.5 ± 1.8 to 538.3 ± 105.3 μg·cm^-2. Propylene glycol (PG) and diethylene glycol monoethyl ether (DEGEE) yielded the highest permeability (P_s) and CBD deposition, while medium-chain triglycerides (MCT) yielded the lowest P_s and deposition. This was due to the difference in apparent partition coefficient (K), which is related to the solubility of CBD in the vehicle. The PG:DEGEE binary vehicle boosted J_ss (1.5-1.6 fold) and deposition (2.0-2.7 folds) significantly, compared to neat DEGEE. The combination of DEGEE with MCT dramatically enhanced J_ss (11-44 fold) and deposition (1.6-4.7 fold). The addition of lipophilic enhancers, laurocapram, and oleic acid, to PG:DEGEE and DEGEE:MCT vehicles significantly reduced J_ss (0.3-0.7 fold) and deposition (0.4-0.8 fold) while nerolidol had no effect. These permeation reductions were found to be related to modification of the K and/or diffusivity values. This study provides useful basic information for the development of CBD formulations intended for transmucosal delivery.

Development, Characterization and Stability Evaluation of Topical Gel Loaded With Ethosomes Containing Achillea millefolium L. Extract

Background: Delivering plant extract at high loading with intact antioxidants and efficient skin permeation always remains a challenge. To address this, we prepared a stable gel formulation containing nanoethosomes loaded with Achillea millefolium L. (AM) extract for topical drug delivery.

Method: The AM extract was tested at first for phytochemical analysis, antioxidant activity, total phenolic and flavonoid content, and FTIR examination. The nanoethosomes containing AM extract were synthesized and characterized by size, surface charge, and morphology, and entrapment efficiency (EE) was determined. The optimized nanoethosomes were then incorporated to develop a topical gel formulation and subjected to skin for permeation, pH, viscosity, and organoleptic evaluation for up to three months.

Results: The AM ethanolic extract demonstrated 88% free radical scavenging activity and notable phenolic and flavonoid contents of up to 123 mg GAE/g and 42 mg QE/g, respectively. The optimized nanoethosomes encapsulated with AM extract (240 nm) were spherical in shape, with −31.1 mV of surface charge, and showed considerable entrapment efficiency (90%). Furthermore, the selected topical gel remained stable during the study period. The Exvivo permeation study of ethosomal gel showed the highest release percentage of 79.8%.

Conclusion: The study concludes that topical gel loaded with nanoethosomes containing AM extract is an encouraging approach for topical drug delivery.

Identification of critical formulation parameters affecting the in vitro release, permeation, and rheological properties of the acyclovir topical cream

To understand effects of formulation variables on the critical quality attributes (CQA) of acyclovir topical cream, this study investigated effects of propylene glycol (PG), poloxamer, and sodium lauryl sulfate (SLS) concentrations, acyclovir particle size, and formulation pH of the acyclovir cream. Fifteen formulations were prepared and characterized for rheological properties, particle size distribution, drug release and in vitro skin permeation. Drug distribution between various phases of the cream was determined. The concentration of soluble acyclovir in the aqueous phase was determined as a surrogate of the equilibrium with other acyclovir species in the cream. The interaction among effects of the formulation variables on the amount of acyclovir retained by skin was also evaluated. The results showed that PG significantly (p < 0.05) increased the yield stress, viscosity, drug concentration in the aqueous phase, and drug release. The PG and SLS significantly (p < 0.05) increased acyclovir retention by skin samples. Particle size of acyclovir inversely affected the drug release. This study revealed that the employed concentrations of PG and SLS and particle size of the dispersed acyclovir are critical formulation variables that should be carefully controlled when developing acyclovir topical creams with desired performance characteristics.

Ethosomes Loaded with Cryptotanshinone for Acne Treatment through Topical Gel Formulation

The aim of this study was to develop ethosomes loaded with cryptotanshinone (CPT) and formulate them as a topical gel for the treatment of acne. Ethosomes were prepared and evaluated for vesicle size, CPT loading and encapsulation efficiency. Optimized ethosomes were formulated as Carbomer 974 gels and compared with conventional hydroethanolic gels for transdermal permeation and skin deposition in vitro. The anti-acne activity and skin irritation of the gel was investigated in rabbits. Optimized ethosomes had an average vesicle size of 69.1 ± 1.9 nm with CPT loading and encapsulation efficiency of 0.445 ± 0.007 mg/mL and 40.31 ± 0.67%, respectively. The transdermal flux and skin deposition of the optimized ethosomal gel were 2.5- and 2.1-times those of conventional gels. The ethosomal gel revealed better anti-acne effect with only slight skin irritation. This study demonstrates that ethosomal formulation is an effective dermal delivery system for CPT, and that CPT ethosomal gels are promising future acne treatments.