Design of Liposomal Lidocaine/Cannabidiol Fixed Combinations for Local Neuropathic Pain Treatment.

The administration of drug fixed combinations by nanocarriers is a new attractive approach since it can allow improvements in both the skin penetration of cargo compounds and their synergistic effects. The cutaneous administration of lidocaine (LD) and cannabidiol (CBD) combination can be useful for the local treatment of neuropathic pain. In fact, these drugs might exert a complementary effect on pain acting on sodium and calcium channels. In this study, the feasibility to deliver this combination in the deeper layers of the skin using deformable liposomes was studied. Based on a study of the drug affinity for lipid components performed by DSC, CBD was loaded in the lipid bilayer for limiting the leakage, while LD was loaded in the inner core by a pH gradient method (G-liposomes) or after previous encapsulation in micelle (DiMiL). The effect of the presence of Tween 80 in the liposome membrane was also evaluated. DiMiL increased both the skin permeation and the retention in the dermis of CBD and LD with respect to G-liposomes (R24dermis: 11.52 ± 2.4 against 4.51 ± 0.8 µg/cm2 for CBD; 19.6 ± 2.9 against 3.2 ± 0.1 µg/cm2 for LD). Moreover, both DiMiL and G-liposomes were more efficient than control formulations carrying free drugs in improving drug skin permeation. Interestingly, in the presence of a drug exerting a fluidizing effect such as CBD, the removal of Tween 80 from the composition led to an improved control of drug release and a higher extent of drug retention in the dermis layer.

Extraction Method and Analysis of Cannabinoids in Cannabis Olive Oil Preparations.

Recently, an increasing number of pharmacists had to supply medicinal products based on Cannabis sativa L. (Cannabaceae), prescribed by physicians to individual patients. Cannabis olive oil preparation is the first choice as a concentrated extract of cannabinoids, even though standardized operative conditions for obtaining it are still not available. In this work, the impact of temperature and extraction time on the concentration of active principles was studied to harmonize the different compounding methods, optimize the extraction process, and reduce the variability among preparations. Moreover, starting from the cannabis inflorescence, the effect of temperature on tetrahydrocannabinolic acid decarboxylation was evaluated. For the analysis, a GC/MS method, as suggested by the Italian Ministry of Health, and a GC/flame ionization detection method were developed, validated, and compared.

In vitro method to evaluate the barrier properties of medical devices for cutaneous use.

Barrier creams (BC) are marketed as cosmetic products or locally-applied medical devices to protect skin against damages induced by chemical agents or physical insults. However, the determination of the BC effectiveness is still a matter of discussion at both the clinical and the regulatory level. In this context, this work aimed at the development of a reliable, reproducible and easy-to-perform experimental protocol for the evaluation of BC performances. Preliminarily, an in vivo method based on the measurement of trans-epidermal water loss had been matter of investigation and was discarded: it required too much time and was not robust and sensitive enough. In vitro, reduction of the permeation of caffeine (used as a model of irritant), through an epidermal membrane mounted on a Franz cell or through a reconstructed 3D human epidermis model, was evaluated. Six BC among oil in water (O/W) or water in oil (W/O) creams were investigated with respect to the petrolatum, which is an efficient impermeable barrier against hydrophilic molecules. Despite minor differences, both methods could rate the effectiveness of the tested products in preventing caffeine exposure. Both methods enable to evaluate and quantify the BC effectiveness in a simple and fast manner. Their application may help regulatory agencies to prevent the marketing of ineffective products for the benefit of consumers.

Investigation of the Effect of Different Emulsifiers on the Transdermal Delivery of EGCG Entrapped in a Polymeric Micelle System.

Epigallocatechin gallate, one of the most active antioxidant compounds, has a low chemical stability and ability to permeate the human epidermis. The encapsulation in polymeric micelles would be beneficial to improve both stability and permeation of epigallocatechin gallate and, therefore, to facilitate the pharmacological effects. Polymeric micelles containing epigallocatechin gallate were incorporated in O/W emulsions prepared by using different types of emulsifying systems. All emulsions were uniform in colour and aspect, without evidences of phase separation after centrifugation at the preparation time and over a 6-month period of storage at room temperature. Emulsions containing epigallocatechin gallate incorporated in polymeric micelles showed a colour variation, probably due to epigallocatechin gallate degradation, over the stability period. The skin permeability study evidenced a significant increase in epigallocatechin gallate permeation after encapsulation in micelles. Pure epigallocatechin gallate was not able to permeate the skin and only limited amounts were retained in the epidermis, while both permeated and retained amounts after 24 h were measured in the case of polymeric micelles containing epigallocatechin gallate. Moreover, the epigallocatechin gallate release and human skin permeability were affected by the type of emulsifier. The epigallocatechin gallate release in the presence of an emulsifier system based on cereal and fruit fibres never occurred. The best results in terms of release and skin permeability were obtained using glycerides of synthetic or semisynthetic origin or esters.

Innovation in Phytotherapy: Is a New Regulation the Feasible Perspective in Europe?

Classical multicomponent preparations mostly derived from traditional usages in Western and Eastern phytotherapy have been under-evaluated for a long time as potential new pharmaceutical products. The regulatory scenario, in particular at the European level, has only recently considered these aspects proposing harmonized guidelines for the pharmaceutical registration of traditional herbal products. Nevertheless, a specific regulation for innovative products based on the combination of precious knowledge arising from traditional usages and modern scientific advancements is still missing. In this paper, we propose a critical review of the current situation with the specific aim of contributing to create a more favorable regulatory environment for the pharmaceutical registration of new and innovative herbal medicinal products.