Development and Optimization of Imiquimod-Loaded Nanostructured Lipid Carriers Using a Hybrid Design of Experiments Approach

Background

Imiquimod (IMQ) is an immunomodulating drug that is approved for the treatment of superficial basal cell carcinoma, actinic keratosis, external genital warts and perianal warts. However, IMQ cream (Aldara^®) has several drawbacks including poor skin permeation, local toxicity, and compromised patient compliance as a topical pharmacological option.

Methods

Our research aimed to develop and optimize nanostructured lipid carriers (NLCs) containing IMQ for the first time using a hybrid design of experiments approach. The optimized formulation was then incorporated into a matrix-type topical patch as an alternative dosage form for topical application and evaluated for IMQ deposition across different skin layers in comparison to the performance of the commercial product. Additionally, our work also attempted to highlight the possibility of implementing environment-friendly practices in our IMQ-NLCs formulation development by reviewing our analytical methods and experimental designs and reducing energy and solvent consumption where possible.

Results

In this study, stearyl alcohol, oleic acid, Tween^® 80 (polysorbate 80), and Gelucire^® 50/13 (Stearoyl polyoxyl-32 glycerides) were selected for formulation development. The formulation was optimized using a 2^k factorial design and a central composite design. The optimized formulation achieved the average particle size, polydispersity index, and zeta potential of 75.6 nm, 0.235, and - 30.9 mV, respectively. Subsequently, a matrix-type patch containing IMQ-NLCs was developed and achieved a statistically significant improvement in IMQ deposition in the deeper skin layers. The IMQ deposition from the patch into the dermis layer and receptor chamber was 3.3 ± 0.9 µg/cm² and 12.3 ± 2.2 µg/cm², while the commercial cream only deposited 1.0 ± 0.8 µg/cm² and 1.5 ± 0.5 µg/cm² of IMQ, respectively.

Conclusion

In summary, IMQ-NLC-loaded patches represent great potential as a topical treatment option for skin cancer with improved patient compliance.

Green Solvents in the Extraction of Bioactive Compounds from Dried Apple Cultivars

New extraction protocols, gas-expanded liquid extraction (GXLE), and ultrasound extraction (UE) have been optimized with an emphasis on using green solvents and maximizing the extraction of 14 selected phenolic compounds, including flavonoid-based compounds and phenolic acids from dried apples. The design of the experiments' approach was applied to optimize the main extraction parameters. Fine tuning included optimization of the flow rate in GXLE and the extraction time for GXLE and UE. Optimized GXLE was carried out with CO₂-ethanol-water (34/53.8/12.2; v/v/v) at a flow rate of 3 mL/min at a temperature of 75 °C and pressure of 120 bar for 30 min. UE with ethanol-water 26/74 (v/v) lasted for 10 min at 70 °C. Both methods differed in solvent consumption and sample throughput, while providing a comparable total phenolic content of 2442 µg/g with an RSD < 10% and 2226 µg/g with RSD < 6%, for GXLE and UE, respectively. Both methods were used in determining the phenolic compounds in five apple cultivars, 'Angold', 'Artiga', 'Golden Delicious', 'Meteor', and 'Topaz'. Phenolic profiles were plotted with chlorogenic acid, catechin, epicatechin, hirsutrin, phloridzin, and guaiaverin as the main components. Statistical evaluation, including pair t-test, Bland-Altman test, and linear regression did not reveal any differences between UE and GXLE results.

Dense is not green: How visual density influences greenness evaluation on environmentally friendly products

Introduction

The visual design of environmentally friendly products has a strong influence on consumer decisions. The study offers a novel insight, suggesting that consumers' perceptions of environmentally friendly products may be affected by the visual density design.

Methods

Four experiments tested the effect of visual density on the perceived greenness of environmentally friendly products.

Results

Study 1 showed that perceived greenness was higher for environmentally friendly products with low visual density design. Study 2 repeatedly confirmed this impact and found that perceived production cost acted as a mediating factor. Study 3 and 4 found two boundary conditions for this effect. Study 3 showed that the effect of visual density design attenuated for consumers with weak holistic thinking. Study 4 further revealed that when emphasizing the use of environment-friendly materials, the effect of visual density design was also attenuated.

Discussion

The findings enrich the discussion on the visual design of green products, extend the effect of visual density on consumer attitudes, and provide practical implications for marketers to choose the appropriate appearance for environmentally friendly products.

Development of three ecological spectroscopic methods for analysis of betrixaban either alone or in mixture with lercanidipine: greenness assessment

Three eco-friendly spectrophotometric methods were developed for determination of the novel anticoagulant drug, betrixaban (BTX). The first method (method A) was based on direct analysis of BTX at 229.4 nm on the zero-order spectrum using methanol as the optimum solvent. While the second method (method B) was based on measuring difference absorption value (ΔA) of BTX at 335 nm, which was obtained from pH-induced spectral difference (difference spectra of BTX in 0.1 M NaOH versus 0.1 M HCl). The third method (method C) was based on measurement of the first-derivative amplitudes of BTX and its co-administered Ca channel blocker lercanidipine (LER) at 304 and 229 nm for simultaneous assay of BTX and LER, respectively. All methods were linear over concentration ranges of 1.0-20.0 and 8.0-80.0 µg ml^-1 for BTX in methods A and B, respectively, and of 1.0-20.0 and 1.0-25.0 µg ml^-1 for BTX and LER, respectively, in method C. The three methods were fully validated and assessed for greenness by three metrics: analytical eco-scale, green analytical procedure index and Analytical GREEnness metrics. The results indicated the validity and greenness of the proposed methods. Moreover, the methods were applied to assay the studied analytes in their dosage forms with high percentage of recovery and low percentage of relative s.d. values.