Is 2-Hydroxypropyl-β-cyclodextrin a Suitable Carrier for Central Administration of Δ9 -Tetrahydrocannabinol? Preclinical Evidence

Preclinical Research Δ⁹ -Tetrahydrocannabinol (THC) is a hydrophobic compound that has a potent antinociceptive effect in animals after intrathecal (IT) or intracerebroventricular (ICV) administration. The lack of a suitable solvent precludes its IT administration in humans. 2-Hydroxypropyl-β-cyclodextrin (HPβCD) increases the water solubility of hydrophobic drugs and is approved for IT administration in humans. To investigate whether HPβCD might be a suitable carrier for ICV administration of THC in rats, two formulations containing THC complexed with HPβCD (30 and 135 μg of THC per animal) and vehicle were administered to Wistar rats. The antinociceptive effect (using the tail flick test), locomotor activity, and body temperature were evaluated. ICV injection of 135 μg of THC/HPβCD complex increased tail flick latency, reduced locomotor activity, and had a dual effect on body temperature. The 30 μg THC/HPβCD formulation only produced a hyperthermic effect. All animals appeared healthy, with no difference between the groups. These results were similar to those obtained in other preclinical studies in which THC was administered centrally using solvents that are unsuitable for IT administration in humans because of their toxicity. Our findings suggest that HPβCD may be a useful carrier for IT administration of THC in humans. Drug Dev Res 78 : 411-419, 2017. © 2017 Wiley Periodicals, Inc.

Note: Fractionation of Sheep Milk Fat Via Supercritical Carbon Dioxide

Supercritical carbon dioxide (SC-CO2) was used for anhydrous ovine milk fat (AMF) fractionation. Two different fractions were obtained: a low molecular weight triacylglycerol (TAG), named fraction E, and a high molecular weight TAG, termed fraction R. Fractionation was performed at different pressure and temperature values. The effect of these parameters on the chemical composition of the two fractions were analysed in relation to the original AMF. Among the searched conditions, 250 bar and 40°C gave the best fractionation results.

Penetration enhancer-containing vesicles: composition dependence of structural features and skin penetration ability

In this work, we focused on how composition and preparation method of vesicles might affect their morphological features and delivery performances. Penetration Enhancer-containing Vesicles, PEVs, vesicles containing a water miscible penetration enhancer (Transcutol® P; 10%, 20%, 30% v/v) and encapsulating diclofenac sodium, were formulated and compared with conventional liposomes. A cheap and unpurified commercial mixture of phospholipids, fatty acids, and triglycerides (Phospholipon® 50) was used, and the effects of this heterogeneous composition (along with the presence or absence of transcutol and the production method) on vesicle morphology, size, surface charge, drug loading, and stability were investigated. The variations in vesicle structure, bilayer thickness, and number of lamellae were assessed by TEM and Small and Wide Angle X-ray Scattering, which also proved the liquid state of the vesicular bilayer. Further, vesicles were evaluated for ex vivo (trans)dermal delivery, and their mode of action was studied performing a pre-treatment test and confocal laser scanning microscopy analyses. Results showed the formation of multi- and unilamellar vesicles that provided improved diclofenac delivery to pig skin, influenced by vesicle lipid composition and structure. Images of the qualitative CLSM analyses support the conclusion that PEVs enhance drug transport by penetrating intact the stratum corneum, thanks to a synergic effect of vesicles and penetration enhancer.

Hofmeister Effects in Biology: Effect of Choline Addition on the Salt-Induced Super Activity of Horseradish Peroxidase and Its Implication for Salt Resistance of Plants

The effect of choline addition on the salt-induced super activity of horseradish peroxidase (HRP) is investigated. HRP is presented in the literature as an efficient H(2)O(2) scavenger, and choline is the precursor of glycine betaine, a strong osmoprotectant molecule. Both the regulations of H(2)O(2) and of osmoprotectant concentrations are implicated in plants in order to counteract salt-induced cell damage. For the oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), sulfate anions were found to play a crucial role in the increase of HRP activity. This induced super activity can be strongly reduced by adding choline chloride. The phenomena provide an example of physicochemical Hofmeister effects playing a central regulatory role in an important biological system.

Biocompatible lipidic formulations: phase behavior and microstructure

Biocompatible systems formulated for use in the food, cosmetic, and pharmaceutical fields are characterized. Ternary phase diagrams of mixtures of natural lipids (glycerol trioleate, glycerol monooleate, diglycerol monooleate, and lecithin) and water were investigated by means of optical microscopy in polarized light and by multinuclear NMR spectroscopy. All systems showed a microemulsion region at high oil content and a large area of coexistence of two liquid crystalline (hexagonal and lamellar) phases. 1H and 13C NMR self-diffusion measurements were used to characterize microstructural features of the microemulsions. On water dilution, the two-phase liquid crystalline region transforms into a creamy emulsion area where the droplets of water are stabilized by both the lamellar and the hexagonal phases, as indicated by 2H NMR measurements. Due to the very effective dispersing action of the two liquid crystalline phases, these emulsions show a high stability toward phase separation.

Addition of hydrophilic and lipophilic compounds of biological relevance to the monoolein/water system II - 13C NMR relaxation study

The addition of hydrophilic and hydrophobic molecules to the 1-monooleoyl glycerol (MO)/water (W) system has been investigated at a molecular level by 13C nuclear magnetic resonance (NMR) relaxation. Depending on the nature of the additive, the liquid crystalline phases of the MO/W binary system are modified. The 13C NMR spin lattice relaxation rates of the various MO carbons were determined in the presence of the additives for different types of L(2) and liquid crystalline phases. Data revealed that local dynamics are independent of type and amount of additive (within 5 wt.%), and also of the type of the structural arrangement. The curvature of the interface does not affect the local mobility of MO carbons, with the exception of the glycerol G3 and the carboxylic C1 carbons. Moreover, the presence of the double bond in the mid part of the hydrocarbon chain induces a levelling in the relaxation rates on the neighboring carbons. The 13C NMR spin lattice relaxation rates at two magnetic field strengths and the Overhauser enhancement were measured in the L(2) phase of the MO/W/sodium decanoate system. The use of a two-step model of relaxation allowed to estimate order parameters, and slow and fast motions of MO in the structured aggregate.

Addition of hydrophilic and lipophilic compounds of biological relevance to the monoolein/water system. I. Phase behavior

The solubilization of hydrophilic and lipophilic molecules, with biological relevance, in the monoolein/water (MO/W) system has been investigated for phase behavior. Small angle X-ray scattering (SAXS), nuclear magnetic resonance (NMR) and optical microscopy (OM) have been used to characterize the microstructure of the liquid crystalline phases. Partial phase diagrams of the MO/W system in the presence of sodium decanoate, 1-adamantanamine hydrochloride, decanoic and dodecanoic acids, acetyl salicilic acid and retinol have been determined. The stability of the various phases has been followed for at least eight months. The polarity and the molecular structure of the additive determine whether it is located at the polar interface or in the apolar region of the lipid layer. Therefore, the additive affects the interfacial curvature of the lipid layer differently, which in turn will trigger transition to disparate phases. A cubic-to-reverse hexagonal phase transition has been observed with time for most of the ternary systems, with the exception of 1-adamantanamine hydrochloride and retinol. The release of free glycerol and oleic acid due to MO hydrolysis has been clearly demonstrated by 13C NMR. This would account for the changes in phase behavior observed with time. The released oleic acid, located in the MO acyl chain region, favors the inverse interfacial curvature. The average lipid dimensions in the cubic and in the reverse hexagonal phases have been calculated from SAXS data.