Evaluation of immunoresponses and cytotoxicity from skin exposure to metallic nanoparticles

Nanotechnology is an interdisciplinary science that has developed rapidly in recent years. Metallic nanoparticles (NPs) are increasingly utilized in dermatology and cosmetology, because of their unique properties. However, skin exposure to NPs raises concerns regarding their transdermal toxicity. The tight junctions of epithelial cells form the skin barrier, which protects the host against external substances. Recent studies have found that NPs can pass through the skin barrier into deeper layers, indicating that skin exposure is a means for NPs to enter the body. The distribution and interaction of NPs with skin cells may cause toxic side effects. In this review, possible penetration pathways and related toxicity mechanisms are discussed. The limitations of current experimental methods on the penetration and toxic effects of metallic NPs are also described. This review contributes to a better understanding of the risks of topically applied metallic NPs and provides a foundation for future studies.

From Petri Dish to Patient: Bioavailability Estimation and Mechanism of Action for Antimicrobial and Immunomodulatory Natural Products

The new era of multidrug resistance of pathogens against frontline antibiotics has compromised the immense therapeutic gains of the 'golden age,' stimulating a resurgence in antimicrobial research focused on antimicrobial and immunomodulatory components of botanical, fungal or microbial origin. While much valuable information has been amassed on the potency of crude extracts and, indeed, purified compounds there are too many reports that uncritically extrapolate observed in vitro activity to presumed ingestive and/or topical therapeutic value, particularly in the discipline of ethnopharmacology. Thus, natural product researchers would benefit from a basic pharmacokinetic and pharmacodynamic understanding. Furthermore, therapeutic success of complex mixtures or single components derived therefrom is not always proportionate to their MIC values, since immunomodulation can be the dominant mechanism of action. Researchers often fail to acknowledge this, particularly when 'null' activity is observed. In this review we introduce the most up to date theories of oral and topical bioavailability including the metabolic processes affecting xenobiotic biotransformation before and after drugs reach the site of their action in the body. We briefly examine the common methodologies employed in antimicrobial, immunomodulatory and pharmacokinetic research. Importantly, we emphasize the contribution of synergies and/or antagonisms in complex mixtures as they affect absorptive processes in the body and sometimes potentiate activity. Strictly in the context of natural product research, it is important to acknowledge the potential for chemotypic variation within important medicinal plants. Furthermore, polar head space and rotatable bonds give a priori indications of the likelihood of bioavailability of active metabolites. Considering this and other relatively simple chemical insights, we hope to provide the basis for a more rigorous scientific assessment, enabling researchers to predict the likelihood that observed in vitro anti-infective activity will translate to in vivo outcomes in a therapeutic context. We give worked examples of tentative pharmacokinetic assessment of some well-known medicinal plants.

Recent Advances in Microneedle Platforms for Transdermal Drug Delivery Technologies

In many clinical applications, the transdermal route is used as an alternative approach to avoid the significant limitations associated with oral drug delivery. There is a long history for drug delivery through the skin utilizing transdermal microneedle arrays. Microneedles are reported to be versatile and very efficient devices. This technique has spurred both industrial and scientific curiosity, due to its outstanding characteristics such as painless penetration, affordability, excellent medicinal efficiency, and relative protection. Microneedles possess outstanding properties for diverse biomedical uses such as the delivery of very large substances with ionic and hydrophilic physicochemical properties. Importantly, microneedles are applicable in numerous biomedical fields such as therapy, diagnosis, and vaccine administration. Microneedles are emerging tools that have shown profound potential for biomedical applications. Transdermal microneedle technologies are likely to become a preferred route of therapeutic substances administration in the future since they are effective, painless, and affordable. In this review, we summarize recent advances in microneedles for therapeutic applications. We explore their constituent materials and fabrication methods that improve the delivery of critical therapeutic substances through the skin. We further discuss the practicality of advanced microneedles used as drug delivery tools.

Recent Progress and Future Directions: The Nano-Drug Delivery System for the Treatment of Vitiligo

Vitiligo is a depigmentation disease that seriously affects the physical health, mental health and quality of life of a patient. Therapeutic aim at control immunoreaction by relieving oxidative stress. Unfortunately, the cuticle barrier function and lack of specific accumulation lead to unsatisfactory therapeutic outcomes and side effects. The introduction and innovation of nanotechnology offers inspiration and clues for the development of new strategies to treat vitiligo. However, not many studies have been done to interrogate how nanotechnology can be used for vitiligo treatment. In this review, we summarize and analyze recent studies involving nano-drug delivery systems for the treatment of vitiligo, with a special emphasis on liposomes, niosomes, nanohydrogel and nanoparticles. These studies made significant progress by either increasing drug loading efficiency or enhancing penetration. Based on these studies, there are three proposed principles for topical nano-drug delivery systems treatment of vitiligo including the promotion of transdermal penetration, enhancement of drug retention and facilitation of melanin regeneration. The presentation of these ideas may provide inspirations for the future development of topical drug delivery systems that will conquer vitiligo.

Transdermal Adhesive Patches Loaded with Ketoprofen Evaluated by Dynamic Detection of Percutaneous Absorption

Topical delivery has many benefits toward NSAIDs administration, and the best-selling transdermal preparation in 2015 was the NSAID patch MOHRUS®. Herein, we report a ketoprofen adhesive patch (KAP) and evaluate the penetration and absorption compared to MOHRUS®. Microdialysis sampling technique was applied to determine drug penetration in the dermis and subcutaneous tissue. Simultaneously, blood samples were withdrawn over time to obtain the drug absorption in plasma. The ketoprofen concentrations in the dermis, subcutaneous tissue, and plasma were compared with the commercially available patch (MOHRUS®). Based on the detection, pharmacokinetic parameters including C_max, T_max, and AUC_0-8h were determined for both the formulations. No significant differences were found in the dermis, subcutaneous tissue, and plasma in rats according to the bioequivalence assessment. The KAP demonstrated multiple therapeutic advantages including the controlled drug release and the sustained drug concentration in the skin as well as in plasma. The pharmacokinetic study coupled with microdialysis sampling provided an effective strategy to evaluate transdermal delivery.

[Association between chemical composition of essential oil with penetration enhancement effect and drug properties of traditional Chinese medicine]

The results of previous studies showed potential correlations between the penetration enhancement effect of essential oils and the drug properties of traditional Chinese medicine based on the data mining method. As chemical composition is the material basis of drug properties of traditional Chinese medicine, this article further analyzed the correlation between the chemical composition of essential oils and the drug properties. Firstly, essential oils were extracted by steam distillation, and then physicochemical parameters of essential oils, such as relative density and refractive index, were measured. The chemical components of 20 essential oils were analyzed by GC-MS, and divided into 12 categories according to skeleton features and functional groups. Finally, Logistic regression analysis was applied to reveal the correlations. The results proved that five flavors, four tastes and channel tropisms showed the correlation with chemical composition of essential oils (P<0.05). In conclusion, there were obvious correlations and regularity between the drug properties of traditional Chinese medicine and the chemical composition of essential oils.

Formulation and Evaluation of a Transferosomal Gel of Famciclovir for Transdermal Use

Objectives

Famciclovir, the drug of choice for cold sores and recurrent genital herpes, has poor oral bioavailability and is associated with numerous side effects. The study aimed to explore the possibility of transdermal application of famciclovir through a transferosome-loaded gelling system to localize the drug at the site of application with improved penetrability, therapeutic effects, and comfort.

Materials and Methods

Transferosomes of famciclovir were prepared using tween 80, phospholipid, and cholesterol. To optimize drug entrapment and the vesicular size of the transferosomes, a central composite design was employed. The optimized formulation was evaluated for physicochemical characteristics, surface morphology, and degree of deformability. The optimized product was included in the Carbopol 940 gelling system. The gel was evaluated for ex vivo permeation, skin irritation, drug deposition at various skin layers, and histopathological analysis.

Results

The design optimization yielded an optimized product (FAMOPT) of nanosized (339 nm) stable vesicles of the transferosome of famciclovir. The surface morphology analysis revealed the formation of nanovesicles without aggregation. Compatibility between the drug and excipients was established. The elasticity of the vesicles demonstrated resistance to leakage. The permeation of the drug was enhanced by 2.8 times. The gel was found to be non-irritating and non-sensitizing to the animal skin. The drug deposition at various skin layers was remarkably improved, indicating effective drug penetration. The histopathological examination further demonstrated the penetration of nano-vesiculate drugs through deeper layers of the skin.

Conclusion

Hence, nano-vesicular famciclovir delivery is a promising alternative to conventional famciclovir delivery with enhanced local and systemic action for herpes treatment.

[Enhancing effect and mechanism of muscone on transdermal penetration of traditional Chinese medicine ingredients with different log P value]

This study aimed to investigate the enhancing effect of muscone on the transdermal penetration of traditional Chinese medicine ingredients and explore its possible mechanism of action. The Franz diffusion cells were employed to investigate the effect of muscone on the transdermal permeation of a series of model drugs with a wide range of log P values. The solubilities at saturation and the stratum corneum(SC)/vehicle partition coefficients of model drugs were measured to evaluate the effect of muscone on drug thermodynamic activities and partition of drugs into SC. Attenuated total reflectance-Fourier transform infrared spectroscopy(ATR-FTIR) was employed to explore the effect of muscone on the molecular structure of SC. The results showed that muscone significantly promoted the transdermal penetration of hydrophilic and lipophilic drugs, and the enhancement ratio(ER) increased with the decrease in the log P. Muscone could interact with the SC lipids to increase the disorder and fluidity of lipid bilayer packing, which improved skin permeability and promoted transdermal absorption of drugs. This study provides a scientific basis for the application of muscone in traditional Chinese medicine topical preparations.

Transdermal Delivery of α-Aminophosphonates as Semisolid Formulations-An In Vitro-Ex Vivo Study

α-Aminophosphonates are organophosphorus compounds with an obvious similarity with α-amino acids. Owing to their biological and pharmacological characteristics, they have attracted the attention of many medicinal chemists. α-Aminophosphonates are known to exhibit antiviral, antitumor, antimicrobial, antioxidant and antibacterial activities, which can all be important in pathological dermatological conditions. However, their ADMET properties are not well studied. The aim of the current study was to provide preliminary information about the skin penetration of three preselected α-aminophosphonates when applying them as topical cream formulations in static and dynamic diffusion chambers. The results indicate that aminophosphonate 1a, without any substituent in the para position, shows the best release from the formulation and the highest absorption through the excised skin. However, based on our previous study, the in vitro pharmacological potency was higher in the case of para-substituted molecules 1b and 1c. The particle size and rheological studies revealed that the 2% cream of aminophosphonate 1a was the most homogenous formulation. In conclusion, the most promising molecule was 1a, but further experiments are proposed to uncover the possible transporter interactions in the skin, optimize the topical formulations and improve PK/PD profiles in case of transdermal delivery.

Ionic Liquid-Based Grapeseed Oil Emulsion for Enhanced Anti-Wrinkle Treatment

OBJECTIVES

To address the poor efficacy and percutaneous penetration of grape seed oil, ionic liquids and nanotechnology were combined to prepare a grape seed oil emulsion.

METHODS

A novel Menthol-CoQ10 ionic liquid and ionic liquid based grapeseed oil emulsion were prepared and confirmed.

RESULTS

The average size of the grapeseed oil emulsion was 218 nm, and its zeta potential was -33.5 mV. The ionic liquid-based grape seed oil emulsion exhibited a transdermal penetration effect 4.63-fold higher than that of ordinary grape seed oil emulsion. Ionic liquid also displayed enhanced efficiency both in vitro and in vivo. It significantly inhibited the production of DPPH free radicals and tyrosinase, inhibited melanin and matrix metalloproteinase-1 (MMP-1) produced by cells, and promoted type I collagen expression in fibroblasts. After 28 days of continuous use, the grapeseed oil emulsion improved the water content of the stratum corneum and the rate of transepidermal water loss, enhanced the firmness and elasticity of the skin, and significantly improved the total number and length of under-eye lines, tail lines, nasolabial folds, and marionette lines on the face.

CONCLUSIONS

Menthol-CoQ10 ionic liquid is a promising functional excipient for both transdermal delivery increase and efficient enhancement. Ionic liquid and nanotechnology for grape seed oil facial mask displayed significantly enhanced efficacy and permeability.