Mucosa-penetrating liposomes for esophageal local drug delivery.

Local drug delivery to the esophagus is hampered by rapid transit time and poor permeability of the mucosa. If some strategies aimed to improve the residence time have been proposed, non-invasive approaches to increase the drug penetration in the mucosa have not been described so far. Herein, we designed mucosa-penetrating liposomes to favor the penetration and retention of curcumin (CURC) in the esophagus. A novel mucosa penetrating peptide (MPP), SLENKGP, was selected by Phage Display and conjugated to pegylated liposomes at different PEG and MPP's surface densities. Pegylation assured a long residence time of liposomes (at least 30 min) in the esophagus in vivo, but it did not favor the penetration of CURC in the mucosa. MPP-decorated liposomes instead delivered a significant higher amount of CURC in the mucosa compared to naked pegylated liposomes. Confocal microscopy studies showed that naked pegylated liposomes remain confined in the superficial layers of the mucosa whereas MPP-decorated liposomes penetrate the whole epithelium. In vitro, MPP reduced the interaction of PEG with mucin, meanwhile favoring the paracellular penetration of liposomes across epithelial cell multilayers. In conclusion, pegylated liposomes represent a valid approach to target the esophagus and the surface functionalization with MPP enhances their penetration in the mucosa.

Electrospinning of pullulan-based orodispersible films containing sildenafil.

Feasibility of electrospinning in the manufacturing of sildenafil-containing orodispersible films (ODFs) intended to enhance oxygenation and to reduce pulmonary arterial pressure in pediatric patients was evaluated. Given the targeted subjects, the simplest and safest formulation was chosen, using water as the only solvent and pullulan, a natural polymer, as the sole fiber-forming agent. A systematic characterization in terms of shear and extensional viscosity as well as surface tension of solutions containing different amounts of pullulan and sildenafil was carried out. Accordingly, electrospinning parameters enabling the continuous production, at the highest possible rate, of defect-free fibers with uniform diameter in the nanometer range were assessed. Morphology, microstructure, drug content and relevant solid state as well as ability of the resulting non-woven films to interact with aqueous fluids were evaluated. To better define the role of the fibrous nanostructure on the performance of ODFs, analogous films were produced by spin- and blade-coating and tested. Interestingly, the disintegration process of electrospun products turned out to be the fastest (i.e. occurring within few s) and compliant with Ph. Eur. and USP limits, making relevant ODFs particularly promising for increasing sildenafil bioavailability, thus lowering its dosages.

Ultrasound-Assisted Extraction of Cannabinoids from Cannabis Sativa for Medicinal Purpose.

Over the past 20 years, the interest in Cannabis oily extracts for medicinal use compounded in pharmacy has consistently grown, along with the need to have preparations of adequate quality. Hot maceration (M) is the most frequently used method to compound oily solutions. In this work, we systematically studied the possibility of using an ultrasonic homogenizer and a sonotrode (US) as an alternative extraction method. Oily solutions were prepared using two available varieties of Cannabis for medicinal use, called FM2 and Bedrocan. All preparations resulted with an equivalent content in CBD and THC, with the advantage of a faster process using US. In particular, 10 min sonication at the amplitude optimized for the sonotrode used (2 or 7 mm) provides not statistically different total Δ9-tetrahydrocannabinol (M-FM2: 0.26 ± 0.02 % w/w; US-FM2: 0.19 ± 0.004 % w/w; M-Bedrocan: 1.83 ± 0.17 % w/w; US-Bedrocan: 1.98 ± 0.01 % w/w) and total cannabidiol (M-FM2: 0.59 ± 0.04 % w/w; US-FM2: 0.58 ± 0.01 % w/w) amounts extracted in refined olive oil. It can therefore be confirmed that sonotrode is an efficient and fast extraction technique and its use is without negative consequence on the solvent properties. Despite DSC evidencing that both maceration and sonication modify the Tonset and enthalpy of the event at about -10 °C, the qualitative characteristics of the oil remained constant for the two treatments and similar to the starting material.

SEBS block copolymers as novel materials to design transdermal patches.

Styrene-block-(ethylene-co-butylene)-block-styrene (SEBS) copolymers are biocompatible elastomers with outstanding stability to UV radiation. This work addresses the potentialities of this class of elastomers for the development of transdermal patches. The influence of SEBS molecular weight, plasticizer and tackifier type on rheological pattern, debonding mechanisms, adhesive properties (i.e., tack, shear and peel adhesion) as well as on the in vitro biopharmaceutical performances (i.e., drug release and skin permeability) was investigated using ibuprofen as model drug. The relationships between the linear and non-linear rheological properties and the main adhesive and biopharmaceutical properties of the prepared patches have been demonstrated. The higher the viscous component of the matrix, the lower its cohesiveness and the faster the drug release rate. The in vitro skin permeability of ibuprofen was not limited by the polymeric matrix, even if compared to the commercial reference product. In conclusion, SEBS copolymers are suitable materials to design drug in-adhesive patches. In particular, SEBS-low molecular weight is the polymer worthy of consideration because of its favorable viscoelastic behavior.

Regulatory framework of pharmaceutical compounding and actual developments of legislation in Europe.

Pharmaceutical preparations are medicines that the pharmacist makes for the special needs of the patients that the pharmaceutical industry cannot comply for economic and logistic reasons. Pharmacy compounding is still an important component of pharmacy practice and a valuable therapeutical service that is an integrant part of the modern health care system, but its legislation is not harmonized among European and US countries. In 2011 the Committee of Ministers of the Council of Europe has adopted a Resolution on quality and safety assurance requirements for medicinal products prepared in pharmacies for the special needs of patients. Aim of this resolution is to harmonize quality assurance and standards for pharmacy-made medicinal products among European countries and to pass the gap in quality assurance and standards between preparation in pharmacies and medicines prepared by the pharmaceutical industry. This article will analyze the actual rules and technical norms that regulate compounding activity and the expectations resultants from the new European and US laws.

The influence of the polar head and the hydrophobic chain on the skin penetration enhancement effect of poly(ethylene glycol) derivatives.

The effect of a homologue series of nonionic surfactants, namely poly(ethylene glycol) (PEG) fatty acid esters, differing in oxyethylene (PEG 8, PEG 12, and PEG 40) and fatty acid (stearate, mono and di-laurate, and mono and di-oleate) chain lengths, on in vitro skin permeability of ketoprofen (KTP) vehicled in plasters was investigated. The drug diffusion through hairless mouse skin as well as the effect of the surfactant type and strength was studied by Franz diffusion cells and ATR-FTIR spectroscopy. The use of PEG stearate series revealed that the surfactant with the largest polar head, namely PEG 40, was ineffective in enhancing the skin permeation of KTP, independently of the plaster concentrations. The effect of the hydrophobic chain was investigated only by using the shortest oxyethylene chains. The experimental results revealed that the oxyethylene chain length of surfactants appeared to be more influent than the alkyl chain. The prediction of the absorption enhancing capability of these PEG derivatives appeared related to the vehicle other than the proper combination of the number of ethylene oxide groups and alkyl groups.