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.

Phytocannabinoids Profile in Medicinal Cannabis Oils: The Impact of Plant Varieties and Preparation Methods.

Cannabis (Cannabis sativa L.) is a highly promising medicinal plant with well-documented effectiveness and growing use in the treatment of various medical conditions. Cannabis oils are mostly used in galenic preparations, due to their easy adjustment of the administration dose, together with the enhanced bioavailability of its active compounds. As stated by the Italian Law (9/11/2015, 279 Official Gazette), "to ensure the quality of the oil-based cannabis preparation, the titration of the active substance(s) should be carried out." This study aims to represent the Italian panorama of cannabis oils, which were analyzed (8,201) to determine their cannabinoids content from 2017 to 2019. After application of the exclusion criteria, 4,774 standardized cannabis oils were included, which belong to different medicinal cannabis varieties and prepared according to different extraction methods. The concentration of the principal cannabinoids was taken into account dividing samples on the basis of the main extraction procedures and cannabis varieties. According to this analysis, the most substantial variations should be attributed to different cannabis varieties rather than to their extraction protocols. This study may be the starting point of preparatory pharmacists to assess the correct implementation of the preparation procedures and the quality of the extracts.

Impact of Lipid Sources on Quality Traits of Medical Cannabis-Based Oil Preparations.

The feasibility of the use of two lipid sources and their impact on the cannabinoid profile, terpene fingerprint, and degradation products in medical cannabis oil preparations during 3 months of refrigerated storage time were investigated. LCHRMS-Orbitrap® and HS-SPME coupled to GC-MS for the investigation of targeted and untargeted cannabinoids, terpenes, and lipid degradation products in Bedrocan® and Bediol® macerated oils were used as analytical approaches. As regards the cannabinoid trend during 90 days of storage, there were no differences between PhEur-grade olive oil (OOPH) and medium-chain triglycerides oil (MCT oil) coupled to a good stability of preparations for the first 60 days both in Bedrocan® and Bediol® oils. MCT lipid source extracted a significant concentration of terpenes compared to olive oil. Terpenes showed a different scenario since MCT oil displayed the strongest extraction capacity and conservation trend of all compounds during the shelf life. Terpenes remained stable throughout the entire storage period in MCT formulations while a significant decrease after 15 and 30 days in Bediol® and Bedrocan® was observed in olive oil. Therefore, MCT oil could be considered a more suitable lipid source compared to olive oil involved in the extraction of medical cannabis for magistral preparations.

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.

Analysis of fluid extracts obtained from Papaver rhoeas petals contaminated with Papaver bracteatum petals.

In this paper, we report a case of misidentification of medicinal plants involving dried petals of Papaver rhoeas (red poppy) contaminated with Papaver bracteatum (scarlet poppy) petals. Preliminary TLC analysis indicated the presence of thebaine either in the fluid extracts or in the petals. It was therefore necessary to carry out an accurate botanic examination of the plant material, which revealed contamination of the red poppy petals with scarlet poppy petals. Moreover, to confirm the adulteration, we developed and validated an efficient, reversed-phase ion pair HPLC method for determination of the alkaloids specific for the Papaver species. Six petal batches and five commercial fluid extracts were analyzed. Only one petal batch from Iran contained thebaine and its analogue oripavine while the alkaloids typical for the Papaver bracteatum species were identified in all fluid extracts, meaning that they were all prepared with contaminated petals.

Regulations applicable to plant food supplements and related products in the European Union.

This paper deals with the current regulatory and legal settings of traditional plant food supplements and herbal medicinal products in the European Union (EU). Marketing of botanicals in foods and food supplements in the EU is subject to several provisions of food law, which cover aspects of safety, production, labelling and product composition, including the use of additives and maximum levels of contaminants and residues. However, due to limited harmonization at the EU level, specific national regulations adopted at a Member State level also apply and mutual recognition is the mechanism through which such products can be marketed in EU countries other than those of origin. Unlike food supplements, marketing of traditional herbal medicinal products is regulated by an ad hoc Directive (i.e. Directive 2004/24/EC) covering in detail all the relevant aspects of these products, including a facilitated registration procedure at national level. However, by distinguishing traditional herbal medicinal products from plant food supplements and establishing selective marketing modalities for these two product categories, the EU has been confronted with implementation difficulties for traditional herbal medicinal products and a lack of homogeneity in the regulatory approaches adopted in different EU Member States. In fact, currently the nature of the commercial botanical products made available to consumers as traditional medicinal products or food supplements, depends largely on the EU Member State under consideration as a consequence of how competent National Authorities and manufacturing companies interpret and apply current regulations rather than on the intrinsic properties of the botanical products and their constituents. When the EU approach is compared with approaches adopted in some non-European countries to regulate these product categories, major differences become evident.

The effects of excipients for topical preparations on the human skin permeability of terpinen-4-ol contained in Tea tree oil: infrared spectroscopic investigations.

This work aimed to evaluate the effect induced by excipients conventionally used for topical dosage forms, namely isopropyl myristate (IPM) or oleic acid (OA) or polyethylene glycol 400 (PEG400) or Transcutol (TR), on the human skin permeability of terpinen-4-ol (T4OL) contained in the pure Tea tree oil. The effect of such excipients was determined by evaluating the absorption of T4OL using human epidermis and the perturbation of the organization of stratum corneum by ATR-FTIR. Among the tested excipients OA enhanced the absorption of T4OL by perturbing the stratum corneum lipid barrier. Other excipients caused a weak enhancement effect and their use should be carefully monitored.

Formulation study of tea tree oil patches.

The antimicrobial, antifungal and anti-inflammatory properties of tea tree oil (TTO), the essential oil of Melaleuca alternifolia are well documented. In order to optimize its therapeutic activity, TTO patches were designed. The aim of this work was the formulation of monolayer patches containing TTO. Moreover, the performance of oleic acid (OA) as a skin penetration enhancer in patches was evaluated. Terpinen-4-ol (T4OL), the main component of TTO, was the marker used to evaluate TTO skin permeability. The permeation study was performed through human epidermis by using Franz diffusion cells. Patches were prepared by using methacrylic copolymers, Eudragit E100 (EuE100) or Eudragit NE (EuNE), and a silicone resin, BioPSA7-4602 (Bio-PSA). TTO and OA contents were fixed at 10% w/w and 3% w/w, respectively. The patches were prepared by a casting method and characterised in terms of T4OL content and skin permeability. All the selected polymers were suitable as the main component of the patch matrix. Since the main critical issue in the use of TTO is related to its toxicity after absorption, the local administration of TTO can take advantage of the use of patches based on EuE100 because of the high retained amount and the low permeation of T4OL. In this matrix, OA slightly increased the T4OL retained amount, improving the efficacy and safety of TTO patches.

Evaluation of the topical anti-inflammatory activity of ginger dry extracts from solutions and plasters.

In this study the skin permeation and the topical anti-inflammatory properties of ginger extracts were investigated. A commercial ginger dry extract (DE) and a gingerols-enriched dry extract (EDE) were evaluated for their in vivo topical anti-inflammatory activity by inhibition of Croton oil-induced ear oedema in mice. Furthermore, the feasibility of an anti-inflammatory plaster containing DE or EDE was evaluated. Since the in vivo activity was evaluated in mice, the ex vivo skin permeation study was performed by using mouse skin or human epidermis. The DE from the acetonic solution exerted a dose-dependent topical anti-inflammatory activity (ID (50) = 142 microg/cm (2)), not far from that of the potent reference substance indomethacin (ID (50) = 93 microg/cm (2)). Similarly, the EDE induced a dose-dependent oedema reduction though its potency (ID (50) = 181 microg/cm (2)) was slightly lower than that of DE. Increase of the 6-gingerol concentration in the extract did not improve the anti-inflammatory activity. The medicated plasters, containing 1 mg/cm (2) of the commercial DE or EDE, had good technological characteristics and exerted a significant antiphlogistic effect, too. By using the plaster containing EDE, the 6-gingerol amount that permeated through human epidermis was 6.9 microg/cm (2) while the amount that passed through mouse skin was 22.1 microg/cm (2). Nevertheless, the amounts of 6-gingerol permeated through human epidermis and mouse skin in the early period (8h) were comparable (p > 0.3). This preliminary result suggests that the anti-inflammatory effect observed in mice could also be exerted in humans.

Evaluation of ex vivo human skin permeation of genistein and daidzein.

The percutaneous absorption of genistein (GEN) and daidzein (DAI), whose oestrogenic-like activity is well known, is scantily investigated. In this work the ability of GEN and DAI to reach therapeutic steady-state plasma concentrations following transdermal administration was studied. The skin permeation studies were conducted by using modified Franz diffusion cell and human epidermis as a membrane. PEG400 was the most effective vehicle for both molecules. On the basis of the ex vivo permeation results and estimating therapeutic plasma concentration, we assume that pure GEN can be efficaciously administered by the transdermal route.