Equivalence assessment of creams with quali-quantitative differences in light of the EMA and FDA regulatory framework

EMA and FDA are upgrading guidelines on assessing the quality and the equivalence of topically applied drug products for developing copies of originator products and supporting post-marketing variations. For topical products having remarkably similar composition, both EMA and FDA accept the equivalence on the bases of the comparison of rheological properties and in vitro drug release constant (k) and skin permeation flux (J) values, instead of clinical studies. This work aims to evaluate the feasibility to expand this approach to variations of the composition of complex semi-solid preparations. Ibuprofen (IB) creams at two different strengths (i.e., 1 % and 10 %) were used as a model formulation. Two formulative changes were performed: (a) the addition of the humectant to simulate a minor post-marketing variation; (b) the substitution of the emulsifying system to simulate a major one. These variations impacted only in 1 % IB formulations where both the equivalences of rheological data and J-values failed. At the highest concentration, the presence of IB crystals broke down the differences in rheological patterns and lead the IB thermodynamic activity at the maximum figuring out an overlapping of the J-values. Such data suggest the combination of these studies, which are thought mainly for the development of copies, could be also applied to the management of post-marketing variations that involve product composition.

3D printed mucoadhesive orodispersible films manufactured by direct powder extrusion for personalized clobetasol propionate based paediatric therapies

The aim of this work is the development and production by Direct Powder Extrusion (DPE) 3D printing technique of novel oral mucoadhesive films delivering Clobetasol propionate (CBS), useful in paediatric treatment of Oral Lichen Planus (OLP), a rare chronic disease. The DPE 3D printing of these dosage forms can allow the reduction of frequency regimen, the therapy personalization, and reduction of oral cavity administration discomfort. To obtain suitable mucoadhesive films, different polymeric materials, namely hydroxypropylmethylcellulose or polyethylene oxide blended with chitosan (CS), were tested and hydroxypropyl-β-cyclodextrin was added to increase the CBS solubility. The formulations were tested in terms of mechanical, physico-chemical, and in vitro biopharmaceutical properties. The film showed a tenacious structure, with drug chemical-physical characteristics enhancement due to its partial amorphization during the printing stage and owing to cyclodextrins multicomponent complex formation. The presence of CS enhanced the mucoadhesive properties leading to a significant increase of drug exposure time on the mucosa. Finally, the printed films permeation and retention studies through porcine mucosae showed a marked retention of the drug inside the epithelium, avoiding drug systemic absorption. Therefore, DPE-printed films could represent a suitable technique for the preparation of mucoadhesive film potentially usable for paediatric therapy including OLP.

Micelles-in-Liposome Systems Obtained by Proliposomal Approach for Cannabidiol Delivery: Structural Features and Skin Penetration

Deformable liposomes represent valuable drug carriers for cutaneous administration. Nevertheless, the fluid lipid membrane can favor the drug leakage during storage. Proliposomes may represent a suitable strategy to solve this issue. As an alternative, a novel carrier, which encloses hydrophobic drugs in the inner core of vesicles, namely, a drug-in-micelles-in-liposome system (DiMiL), has been proposed. In this work, we investigated the possible advantages of combining these two approaches to obtain a formulation able to enhance the skin penetration of cannabidiol (CBD). Proliposomes were prepared by spray-drying or slurry method testing lactose, sucrose, and trehalose as carriers at different sugar/lipid weight ratios. The ratio between soy-phosphatidylcholine (main lipid) and Tween 80 was instead fixed at 85:15 w/w. DiMiL systems were extemporaneously obtained by the hydration of proliposomes with a Kolliphor HS 15 micellar dispersion (containing CBD, when appropriate). Based on the technological properties, sucrose and trehalose at 2:1 sugar/lipid ratio resulted in the best carriers for spray-dried and "slurried" proliposomes, respectively. Cryo-EM images clearly showed the presence of micelles in the aqueous core of lipid vesicles and the presence of sugars did not alter the structural organization of DiMiL systems, as demonstrated by SAXS analyses. All formulations were highly deformable and able to control CBD release regardless of the presence of sugar. The permeation through human epidermis of CBD carried by DiMiL systems was significantly improved compared to that obtained loading the drug in conventional deformable liposomes with the same lipid composition or in an oil solution. Furthermore, the presence of trehalose led to a further slight increase of the flux. Altogether, these results demonstrated that proliposomes may be a valuable intermediate for the preparation of deformable liposome-based cutaneous dosage forms, improving the stability without compromising the overall performances.

Caffeic Acid-Grafted PLGA as a Novel Material for the Design of Fluvastatin-Eluting Nanoparticles for the Prevention of Neointimal Hyperplasia

Drug-eluting nanoparticles (NPs) administered by an eluting balloon represent a novel tool to prevent restenosis after angioplasty, even if the selection of the suitable drug and biodegradable material is still a matter of debate. Herein, we provide the proof of concept of the use of a novel material obtained by combining the grafting of caffeic acid or resveratrol on a poly(lactide-co-glycolide) backbone (g-CA-PLGA or g-RV-PLGA) and the pleiotropic effects of fluvastatin chosen because of its low lipophilic profile which is challenging for the encapsulation in NPs and delivery to the artery wall cells. NPs made of such materials are biocompatible with macrophages, human smooth muscle cells (SMCs), and endothelial cells (ECs). Their cellular uptake is demonstrated and quantified by confocal microscopy using fluorescent NPs, while their distribution in the cytoplasm is verified by TEM images using NPs stained with an Ag-PVP probe appositely synthetized. g-CA-PLGA assures the best control of the FLV release from NP sizing around 180 nm and the faster SMC uptake, as demonstrated by confocal analyses. Interestingly and surprisingly, g-CA-PLGA improves the FLV efficacy to inhibit the SMC migration, without altering its effects on EC proliferation and migration. The improved trophism of NPs toward SMCs, combined with the excellent biocompatibility and low modification of the microenvironment pH upon polymer degradation, makes g-CA-PLGA a suitable material for the design of drug-eluting balloons.

Trends in the Characterization Methods of Orodispersible Films

The recent increased interest in orodispersible films (ODF) stems from their ideal potential to circumvent several pharmacotherapy-related problems, such as improved medication compliance and adherence, especially in children, elderly and uncooperative patients. Their administration is well accepted by the majority of patients because ODF dissolve upon contact with the saliva in the oral cavity without the need for water intake. ODF application in personalized pharmacotherapy is currently being exploited. Moreover, innovative preparation methods and characterization technologies have been evolving in recent years, highlighting a promising future both from the technological and clinical standpoints. However, the key obstacles to the attainment of full potential of ODF in the pharmaceutical field is the lack of harmonized and well-defined quality characterization procedures, standard evaluation parameters, guidance on appropriate final product properties and specifications. This review provides an appraisal on the ODF characterization methods from slurries to the finished medicinal products with a specific focus on the technologies suitable for identification, quantification, and quality evaluation of extemporaneously prepared ODF on small batches in individualized pharmacotherapy. Generally, there is a paradigm shift from the use of the conventional quality evaluation tools and/or protocols for oral solid dosage forms to characterize ODF to more specific equipment and procedures that suit the peculiarities of the ODF.

Design and development of topical liposomal formulations in a regulatory perspective

The skin is the absorption site for drug substances intended to treat loco-regional diseases, although its barrier properties limit the permeation of drug molecules. The growing knowledge of the skin structure and its physiology have supported the design of innovative nanosystems (e.g. liposomal systems) to improve the absorption of poorly skin-permeable drugs. However, despite the dozens of clinical trials started, few topically applied liposomal systems have been authorized both in the EU and the USA. Indeed, the intrinsic complexity of the topically applied liposomal systems, the higher production costs, the lack of standardized methods and the more stringent guidelines for assessing their benefit/risk balance can be seen as causes of such inefficient translation. The present work aimed to provide an overview of the physicochemical and biopharmaceutical characterization methods that can be applied to topical liposomal systems intended to be marketed as medicinal products, and the current regulatory provisions. The discussion highlights how such methodologies can be relevant for defining the critical quality attributes of the final product, and they can be usefully applied based on the phase of the life cycle of a liposomal product: to guide the formulation studies in the early stages of development, to rationally design preclinical and clinical trials, to support the pharmaceutical quality control system and to sustain post-marketing variations. The provided information can help define harmonized quality standards able to overcome the case-by-case approach currently applied by regulatory agencies in assessing the benefit/risk of the topically applied liposomal systems.

Rationalizing the Design of Hyaluronic Acid-Decorated Liposomes for Targeting Epidermal Layers: A Combination of Molecular Dynamics and Experimental Evidence

This work provides information on the features of low molecular weight hyaluronic acid (HA)-decorated liposomes to target resveratrol (RSV) in the skin. Deformable liposomes were made of soy-phosphatidylcholine with Tween 80 as the fluidizing agent. For HA conjugation, three different phosphoethanolamines were tested: 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE). The different phosphoethanolamine-HA conjugates were inserted into the liposome bilayer by hydration (HA on both faces of the bilayer) or by the postinsertion method (HA only on the external face of the bilayer). The effect of these variables on deformability was experimentally assessed by an in-house method (K value, the lower the value, the higher the deformability) and molecular dynamics (MD) simulations. The results showed that the K values of HA-liposomes obtained by hydration were higher than the K values of HA-liposomes prepared by postinsertion, and both were at least 10-fold higher than the K values of the corresponding plain liposomes. The nature of the lipid anchor played a key role in deformability (DMPE > DOPE > DPPE) with high variability in the case of DOPE formulations. These data were justified by the trends found in silico for the bilayer bending modulus and the HA end-to-end distance. In addition to liposome flexibility, the HA extent seems to be the key factor governing the skin penetration of RSV. When the extent is higher, the amount of the drug retained in the skin is larger. Regarding skin permeation, a parabolic trend was recorded, and the optimal amount to favor skin permeation was an approximately 30 HA/phospholipid (μg/mmol) ratio. This study reports the first piece of evidence that it is possible to control drug delivery in the skin by tuning the amount of HA on the vesicle surface.

Design and development of plastic antibodies against SARS-CoV-2 RBD based on molecularly imprinted polymers that inhibit in vitro virus infection

The present research study reports the development of plastic antibodies based on Molecularly Imprinted Polymers (MIPs) capable of selectively binding a portion of the novel coronavirus SARS-CoV-2 spike protein. Indeed, molecular imprinting represents a very promising and attractive technology for the synthesis of MIPs characterized by specific recognition abilities for a target molecule. Given these characteristics, MIPs can be considered tailor-made synthetic antibodies obtained by a templating process. After in silico analysis, imprinted nanoparticles were synthesized by inverse microemulsion polymerization and their ability to prevent the interaction between ACE2 and the receptor-binding domain of SARS-CoV-2 was investigated. Of relevance, the developed synthetic antibodies are capable of significantly inhibiting virus replication in Vero cell culture, suggesting their potential application in the treatment, prevention and diagnosis of SARS-CoV-2 infection.

Extemporaneous printing of diclofenac orodispersible films for pediatrics

OBJECTIVE

The possible application of a hot-melt ram extrusion printing to the preparation of diclofenac orodispersible films (ODF) made of maltodextrin was studied focusing the attention on the effects of taste-masking agents (i.e. namely mint, licorice-mint, and sucralose) and an opacifier (titanium dioxide [TiO₂]).

SIGNIFICANCE

This is a proof-of-concept of the feasibility to print ODF loaded with a thermosensitive drug substance by hot-melt technologies.

METHODS

Diclofenac sodium (DNa) ODF made of maltodextrin (dextrose equivalent (DE) = 6 ) plasticized with glycerol were prepared by hot-melt extrusion printing. ODF were characterized for disintegration time, drug content, and solid state, in vitro dissolution in deionized water and simulated salivary fluid at pH 5.7, tensile, and adhesive properties. Moreover, the stability of ODF was assessed in accelerated conditions over six months.

RESULTS

After the preparation, no variation in drug solid state was evident and the formation of impurity A of DNa was detected, even if it remained below the Pharmacopoeia (Ph. Eur.) limits (< 0.2%). Only the addition of DNa significantly improved the ODF tensile properties: the tensile strength increased from 0.17 ± 0.03 MPa (placebo ODF) to 2.21 ± 0.54 MPa (p ≤ 0.03). All ODF disintegrated in about 1 min, and the t_80% was lower than 3 min. TiO₂ reduced the static and dynamic peel forces (p ≤ 0.006) favoring the ODF detachment from the primary packaging material. During the accelerated stability study, ODF were easy to handle without fracture; the drug content, impurity A, and dissolution profiles remained superimposable.

CONCLUSION

Hot-melt printing can be suitable to prepare palatable ODF loaded with bitter thermosensitive drugs.

Transplantation of autologous extracellular vesicles for cancer-specific targeting

Nano- and microsized extracellular vesicles (EVs) are naturally occurring cargo-bearing packages of regulatory macromolecules, and recent studies are increasingly showing that EVs are responsible for physiological intercellular communication. Nanoparticles encapsulating anti-tumor theranostics represent an attractive “exosome-interfering” strategy for cancer therapy.

Methods: Herein, by labeling plasma-derived EVs with indocyanine green (ICG) and following their biodistribution by in vivo and ex vivo imaging, we demonstrate the existence of nanoparticles with a highly selective cancer tropism in the blood of colorectal cancer (CRC) patients but not in that of healthy volunteers.

Results: In CRC patient-derived xenograft (PDX) mouse models, we show that transplanted EVs recognize tumors from the cognate nanoparticle-generating individual, suggesting the theranostic potential of autologous EVs encapsulating tumor-interfering molecules. In large canine breeds bearing spontaneous malignant skin and breast tumors, the same autologous EV transplantation protocol shows comparable safety and efficacy profiles.

Conclusions: Our data show the existence of an untapped resource of intercellular communication present in the blood of cancer patients, which represents an efficient and highly biocompatible way to deliver molecules directly to the tumor with great precision. The novel EV-interfering approach proposed by our study may become a new research direction in the complex interplay of modern personalized cancer therapy.

Data on compounding lopinavir and ritonavir suspension for non-cooperative COVID-19 patients

The COVID-19 outbreak is now one of the most critical crises to manage for most of national healthcare systems in the world. The situation is complicated by the absence of vaccines and authorized pharmacological treatments, except for remdesivir. In this context, many medicaments, including different Ebola and HIV antivirals, are used off-label in the hospital wards as life-treating medicines for COVID-19 patients. Authorized medicaments manipulation is sometimes necessary because they are not always formulated to be administered to non-cooperative patients or they are in shortage. It is this the case of the fixed combination of lopinavir/ritonavir, which was extensively used in the first phase of the outbreak inducing a shortage of the oral solution available in the EU market. This work provides data on size distribution, osmolarity other than drug chemical stability of a lopinavir/ritonavir extemporaneous preparation made by using the solid dosage form (i.e., tablet) available on the market as drug source. The reported data indicate that such preparation is suitable to be delivered through a nasogastric tube, and enough stable for two weeks from the preparation at room temperature.

Data on chloroquine/hydroxychloroquine content in compounded oral suspension after filtration and centrifugation

The COVID-19 outbreak is spreading worldwide pushing the national healthcare systems to find effective protocols to prevent contagion and to reduce the patients' mortality and the severity of long-term effects. In the absence of authorised pharmacological treatments, chloroquine, and hydroxychloroquine, which are known as anti-malaria drugs, had been widely used off-label until concerns about their efficacy/safety limited their use to hospitalized patients affected by severe COVID-19. Regardless of their clinical use, their manipulation is necessary since the pure drug substance is not always promptly available and most of the drug products available on the market are tablets designed to be ingested; no liquid dosage forms are available. These are needed for children and the enteral nutrition of inpatients of intensive care units. Considering that both chloroquine and hydroxychloroquine are BCS class I, proper procedures for purifying the preparation from the insoluble excipients may be adopted to avoid clogging of a nasogastric tube and to reduce the drug content variability in the administered doses. The data in this article indicate that compounded oral suspensions containing chloroquine and hydroxychloroquine can be filtered and/or centrifuged without altering the drug assay of the preparation.

Design of pressure-sensitive adhesive suitable for the preparation of transdermal patches by hot-melt printing

This work aimed to design low-melting pressure sensitive adhesives and to demonstrate the feasibility of the preparation of (trans)dermal patches by hot-melt ram extrusion printing. This approach allows defining both the geometry of (trans)dermal patch and the drug strength easily according to patient needs. The preparation steps are the mixing of a poly-ammonium methacrylate polymer (i.e. Eudragit RL and RS) with a suitable amount of plasticizer (triacetin or tributyl citrate) and drug (ketoprofen or nicotine), the melting in the ram extruder, and the printing on the backing layer foil. The formulations were characterized in terms of rheological and adhesive properties, in vitro drug release and skin permeation profiles. The (trans)dermal patches made of Eudragit RL or Eudragit RS plasticized with the 40% triacetin could be printed at 90 °C giving formulations with suitable adhesive properties and without cold flow after 1 month of storage at 40 °C. Furthermore, the overall results showed that the performances of printed (trans)dermal patches overlapped those made by solvent casting, suggesting that the proposed solvent-free technology can be useful to treat cutaneous pathologies when the availability of (trans)dermal patches with size and shape that perfectly fit with the skin area affected by the disease improves the safety of the pharmacological treatment.

Preserving the Integrity of Liposomes Prepared by Ethanol Injection upon Freeze-Drying: Insights from Combined Molecular Dynamics Simulations and Experimental Data

The freeze-drying of complex formulations, such as liposomes, is challenging, particularly if dispersions contain residual organic solvents. This work aimed to investigate the effects of possible protectants, namely sucrose, trehalose and/or poly(vinyl pyrrolidone) (PVP), on the main features of the dried product using a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)-based liposomal dispersion prepared by ethanol injection and containing ethanol up to 6%, as a model. The interactions among vesicles and protectants were preliminary screened by Molecular Dynamics (MD) simulations, which have been proved useful in rationalizing the selection of protectant(s). The freeze-drying protocol was based on calorimetric results. Overall data suggested a stronger cryo-protectant effect of trehalose, compared with sucrose, due to stronger interactions with the DPPC bilayer and the formation of highly ordered clusters around the lipids. The effect further improved in the presence of PVP. Differently from the other tested protectants, the selected trehalose/PVP combination allows to preserve liposome size, even in the presence of 6% ethanol, as demonstrated by Nanoparticle Tracking Analysis (NTA). Nevertheless, it should be also underlined that cakes blew out at an ethanol concentration higher than 1% v/v, probably due to the poor cohesion within the cake and solvent vapour pressure upon sublimation.

Data on the stability of darunavir/cobicistat suspension after tablet manipulation

The COVID-19 outbreak is now one of the most critical crises to manage for most of the national healthcare systems in the world. In the absence of authorised pharmacological treatments, many antiretrovirals, including darunavir/cobicistat fixed combination, are used off-label in the hospital wards as life-treating medicines for COVID-19 patients. Unfortunately, for most of them, the drug products available on the market are not designed to be administered by a nasogastric tube to inpatients of intensive care units. Therefore, their manipulation, even if it can strongly affect the product quality, is necessary for the preparation of suspension to meet patients' need. In this situation, it is urgent to provide data and guidance to support hospital pharmacists and clinicians in their activity. The data in this article indicate that darunavir/cobicistat suspensions compounded by pharmacists using as active ingredient a commercially available tablet can be stable at least for one week.

Regulatory aspects and quality controls of polymer-based parenteral long-acting drug products: the challenge of approving copies

To assure the safety and the efficacy of a medicinal product, quality and batch-to-batch reproducibility need to be guaranteed. In the case of parenteral long-acting products, the European Union (EU) and US Regulatory Authorities provide different indications, from the classification to the in vitro release assays related to such products. Despite their relevance, there are few in vitro experimental set-ups enabling researchers to discriminate among products with different in vivo behaviors. Consequently, most copies are authorized through hybrid instead of generic applications. Here, we review the actual regulatory frameworks to evaluate the in vitro release of drugs from polymer-based long-acting parenterals to highlight the directions followed by the Regulatory Agencies in the USA and EU.

Lysozyme Mucoadhesive Tablets Obtained by Freeze-Drying

Lysozyme is particularly attractive for the local treatment of oral pathologies related to microbiological infections. However, the requirement of a prolonged release is difficult to achieve because of saliva swallowing and of the protein denaturation which can occur during production and storage of a dosage form. This work demonstrates the feasibility to prepare lysozyme mucoadhesive tablets by freeze-drying. Tablets were prepared by using alginate (ALG) physically "cross-linked" with calcium ion and different grades of hydroxypropyl methylcellulose (HPMC) (i.e., E5, E50, or K100). The tablets were characterized in terms of swelling or erosion behavior, in vitro mucoadhesive properties, lysozyme activity (Micrococcus lysodeikticus), drug release and ability to inactivate Staphylococcus aureus. The formulations prepared with HPMC K100 were discarded because of the fast erosion. All other formulations allowed a sustained release over at least 6 h. Independently of composition, lysozyme activity (78,311 ± 1873 Units/mg) significantly decreased in the case of tablets containing 5% and 10% w/w of protein (55,000 Units/mg and 33,000 Units/mg, respectively). Conversely, no modifications occurred in the case of tablets containing 1% w/w lysozyme. The formulation prepared by ALG/HPMC E5 7/3 ratio was efficacious against S. aureus. After 3 months of storage at 5 ± 3°C, no significant decrease in lysozyme activity was observed.

Biorelevant release testing of biodegradable microspheres intended for intra-articular administration

Characterization of controlled release formulations used for intra-articular (IA) drug administration is challenging. Bio-relevant synovial fluids (BSF), containing physiologically relevant amounts of hyaluronic acid, phospholipids and proteins, were recently proposed to simulate healthy and osteoarthritic conditions. This work aims to evaluate the performance of different controlled release formulations of methylprednisolone (MP) for IA administration, under healthy and disease states simulated conditions. Microspheres differed in grade of poly(lactide-co-glycolide) and in the theoretical drug content (i.e. 23 or 30% w/w). Their performance was compared with the commercially available suspension of MP acetate (MPA). Under osteoarthritic state simulated condition, proteins increased the MPA release and reduced the MPA hydrolysis rate, over 48 h. Regarding microspheres, the release patterns over 40 days were significantly influenced by the composition of BSF. The pattern of the release mechanism and the amount released was affected by the presence of proteins. Protein concentration affected the release and the concentration used is critical, particularly given the relevance of the concentrations to target patient populations, i.e. patients with osteoarthritis.

Data on spray-drying processing to optimize the yield of materials sensitive to heat and moisture content

Full dataset used to evaluate the spray-drying process parameters on the preparation of a micronized powder made of maltodextrin (MDX) is herein reported. The process parameters (namely, feed flow rate (FFR); inlet temperature (T_in); nozzle pressure (P_N); noozle diameter (D_N) and difference of pressure between cyclone and chamber (ΔP)) were screened through a Central Composite Design (2^5-1; 2^∗5; n_C=2) using the following responses: product yield, powder size and size dispersity (span) and the outlet temperature of the exhausted air (T_out). Data indicate that, in the considered range, only the product yield and the powder median diameter were influenced by the process. The product yield progressively increased on increasing inlet temperature and decreasing the amount or the size of droplets to be dried. The powder median diameter was positively influenced only by the nozzle diameter. This data presented in this article completes a wider work related on "Maltodextrins as drying auxiliary agent for the preparation of easily resuspendable nanoparticles" (Magri et al., 2019).

In Vitro Anticancer Activity of Extracellular Vesicles (EVs) Secreted by Gingival Mesenchymal Stromal Cells Primed with Paclitaxel

Interdental papilla are an interesting source of mesenchymal stromal cells (GinPaMSCs), which are easy to isolate and expand in vitro. In our laboratory, GinPaMSCs were isolated, expanded, and characterized by studying their secretome before and after priming with paclitaxel (PTX). The secretome of GinPaMSCs did not affect the growth of cancer cell lines tested in vitro, whereas the secretome of GinPaMSCs primed with paclitaxel (GinPaMSCs/PTX) exerted a significant anticancer effect. GinPaMSCs were able to uptake and then release paclitaxel in amounts pharmacologically effective against cancer cells, as demonstrated in vitro by the direct activity of GinPaMSCs/PTX and their secretome against both human pancreatic carcinoma and squamous carcinoma cells. PTX was associated with extracellular vesicles (EVs) secreted by cells (EVs/PTX), suggesting that PTX is incorporated into exosomes during their biogenesis. The isolation of mesenchymal stromal cells (MSCs) from gingiva is less invasive than that from other tissues (such as bone marrow and fat), and GinPaMSCs provide an optimal substrate for drug-priming to obtain EVs/PTX having anticancer activity. This research may contribute to develop new strategies of cell-mediated drug delivery by EVs that are easy to store without losing function, and could have a superior safety profile in therapy.

A new melatonin oral delivery platform based on orodispersible films containing solid lipid microparticles

An innovative delivery system for melatonin, based on the incorporation of solid lipid microparticles in orodispersible films (ODFs) made of maltodextrin, was designed and developed. Lipid microparticles at two different melatonin concentrations (10 and 20% w/w) were produced by the spray congealing technology using two different lipid carrier (tristearin and hydrogenated castor oil) and characterized in terms of size, solid state, drug loading and drug release pattern. Tristearin microparticles were discarded due to a polymorphic modification of the carrier. The incorporation of hydrogenated castor oil microparticles in ODFs by using the casting method did not alter significantly the shape and dimension of the microparticles and the mechanical properties (elasticity and strength) of the films, which remained acceptable for manufacturing and handling. The in vitro release studies performed in saliva, gastric and intestinal simulated media on ODFs containing melatonin loaded in hydrogenated castor oil microparticles revealed the possibility to combine with an immediate release of the drug and a sustained release over at least 5 h period. In conclusion, the proposed drug delivery system maintains the advantages of ODFs, i.e. the suitability to be swallowed without water, and permits the tuning of drug release according to the clinical needs by modulating the ratio of free and microencapsulated drug in the ODF.

Medicated Foams and Film Forming Dosage Forms as Tools to Improve the Thermodynamic Activity of Drugs to be Administered Through the Skin

Medicated foams and film forming systems are dosage forms formulated to undergo a con-trolled metamorphosis when applied on the skin. Indeed, due to the presence of propellant or a particular air-spray foam pump, a liquid can generate foam when applied on the stratum corneum, or a liquid or conventional dosage form can form on the skin a continuous film as a consequence of the solvent evapora-tion. Thanks to these controlled modifications, the drug thermodynamic activity increases favoring the skin penetration and, therefore, the bioavailability with respect to conventional semi-solid and liquid dosage forms. Furthermore, the available clinical data also evidence that these dosage forms improve the patient’s compliance. The main formulative aspects of medicated foams and film forming systems are reviewed with the aim to underline the possible advantages in terms of biopharmaceutical performances and pa-tient’s adherence.

Data on the determination of human epidermis integrity in skin permeation experiments by electrical resistance

The data presented in this article are related to the research article entitled "Design of in vitro skin permeation studies according to the EMA Guideline on quality of transdermal patches" (https://doi.org/10.1016/j.ejps.2018.09.014) (Cilurzo et al., 2018) [1]. In vitro permeation studies are generally carried out by Franz's diffusion cell method using human epidermis as a membrane (Franz, 1975) [2]. The evaluation of membrane integrity is mandatory to assure the quality of the experiments. However, the methods used for this determination are different and the results are strictly dependent on the operative conditions. The article reports the electrical resistance values of human epidermis samples and in vitro skin permeability data of caffeine and benzoic acid. The data are used to establish a cut-off suitable for checking the skin integrity. This information may be useful to enable critical or extended analyses in order to contribute to the development of a compendial method.

Innovative pharmaceutical approaches for the management of inner ear disorders

The sense of hearing is essential for permitting human beings to interact with the environment, and its dysfunctions can strongly impact on the quality of life. In this context, the cochlea plays a fundamental role in the transformation of the airborne sound waves into electrical signals, which can be processed by the brain. However, several diseases and external stimuli (e.g., noise, drugs) can damage the sensorineural structures of cochlea, inducing progressive hearing dysfunctions until deafness. In clinical practice, the current pharmacological approaches to treat cochlear diseases are based on the almost exclusive use of systemic steroids. In the last decades, the efficacy of novel therapeutic molecules has been proven, taking advantage from a better comprehension of the pathological mechanisms underlying many cochlear diseases. In addition, the feasibility of intratympanic administration of drugs also permitted to overcome the pharmacokinetic limitations of the systemic drug administration, opening new frontiers in drug delivery to cochlea. Several innovative drug delivery systems, such as in situ gelling systems or nanocarriers, were designed, and their efficacy has been proven in vitro and in vivo in cochlear models. The current review aims to describe the art of state in the cochlear drug delivery, highlighting lights and shadows and discussing the most critical aspects still pending in the field.

Lyophilization of Liposomal Formulations: Still Necessary, Still Challenging

Nowadays, the freeze-drying of liposome dispersions is still necessary to provide a solid dosage form intended for different routes of administration (i.e., parenteral, oral, nasal and/or pulmonary). However, after decades of studies the optimization of process conditions remains still challenging since the freezing and the dehydration destabilize the vesicle organization with the concomitant drug leakage. Starting from the thermal properties of phospholipids, this work reviews the main formulation and process parameters which can guarantee a product with suitable characteristics and increase the efficiency of the manufacturing process. In particular, an overview of the cryo- and/or lyo-protective mechanisms of several excipients and the possible use of co-solvent mixtures is provided. Attention is also focused on the imaging methods recently proposed to characterize the appearance of freeze-dried products and liposome dispersions upon reconstitution. The combination of such data would allow a better knowledge of the factors causing inter-vials variability in the attempt to improve the quality of the final medicinal product.

Simultaneous quantification of Gemcitabine and Irinotecan hydrochloride in rat plasma by using high performance liquid chromatography-diode array detector

In this manuscript we aimed at the simultaneous separation and quantification of Gemcitabine and Irinotecan hydrochloride (injected both as single components and in combination) from Sprague Dawley rat plasma by using a validated method obtained through the use of a High Performance Liquid Chromatography (HPLC)-diode array detector (DAD). Gemcitabine and Irinotecan hydrochloride were detected and quantified using a Zorbax Extend C-18 column (250 mm × 4.6 mm; 5 μm particle size) in gradient elution mode. The chromatographic analyses were carried out in 15 min. The analytical mode was calibrated and validated in the concentration range from 0.1 to 18 μg/mL both for Gemcitabine and Irinotecan hydrochloride. Sprague Dawley rat plasma was used to perform the analysis. 3-methylxanthine was the internal standard. The weighted-matrix matched standard curves of Gemcitabine and Irinotecan hydrochloride showed a good linearity up to 18 μg/mL. Parallelism tests were also performed to evaluate whether the over-range samples could be analyzed after dilution without affecting the analytical performance. The intra- and inter-day precision (RSD%) values of Gemcitabine and Irinotecan hydrochloride were ≤7.14% and ≤11.5%, respectively. The intra- and inter-day trueness (Bias%) values were in the range from -11.5% to 1.70% for both drugs. The analytical mode performance was further tested after collecting Sprague Dawley rat plasma following a single-dose administration of chemotherapeutics or their association. The validated HPLC-DAD method allowed the simultaneous quantification of Gemcitabine and Irinotecan hydrochloride in the rat plasma, besides the evaluation of the pharmacokinetic parameters and drug delivery.

The effectiveness of long-term course of Sterimar Mn nasal spray for treatment of the recurrence rates of acute allergic rhinitis in patients with chronic allergic rhinitis

Background

The "cost of illness" of the acute allergic rhinitis (AR) episodes in patients with chronic AR is very high in terms of therapy and quality of life. AR represents a worldwide health problem; despite the fact that many standardized treatments have been proposed and used, the recurrence rate of acute rhinitis episodes in springtime is always higher.

Materials and methods

Sixty consecutive patients (13 F and 17 M in group A, 15 F and 15 M in group B; p=0.60) with chronic AR were enrolled in this prospective, controlled clinical trial. Thirty patients were treated daily for the same 5 months of the following year (2013) with isotonic seawater nasal spray enriched with manganese (Sterimar Mn; 4 puffs/day), whereas 30 patients received only the standard care and were used as control group.

Results

A 5 months course treatment with the nasal Sterimar Mn was able to decrease, significantly (p<0.001), the number of episodes of acute AR (6.33 episodes in the group of treated patients versus 9.33 episodes in control group). Also, the 5 months quality of life reduced over time (Visual Analogue Scale 5th month 9.90 in treated group versus Visual Analogue Scale 5th month 8.72 in control group: p<0.001) without the typical adverse effects of the AR standard care therapy.

Conclusion

This study shows the effectiveness of the use of Sterimar Mn for a 5 months therapy in terms of reduction of the number of episodes of acute AR and effectiveness of intrasubject improvement of Visual Analog Scale (quality of life).

Tuning the rheological properties of an ammonium methacrylate copolymer for the design of adhesives suitable for transdermal patches

Eudragit® RL (EuRL) matrices have been proposed to release a drug to the skin. However, no information is available on both viscoelastic and adhesive properties of such compositions. This work focuses on the evaluation of both rheological and texture properties of EuRL differently plasticized with tributyl citrate (TBC) or triacetin (TRI) in order to design a pressure sensitive adhesive suitable for transdermal patch preparation. The patch adhesive properties (i.e. tack, peel adhesion and shear adhesion) as well as its in vitro biopharmaceutical performances were determined after loading ibuprofen, ketoprofen or flurbiprofen. The addition of 40-60% w/w TBC or 40-50% w/w TRI to EuRL permitted to obtain matrices with the desired adhesive properties. Moreover, the increase of plasticizer content and loading of the drug reduced the relaxation time (τ_R). Consequently, the shear adhesion values decreased and the in vitro drug release constants (k) increased. Indeed, the k values from patches containing TBC were lower than the corresponding with TRI because of the lower fluidity of such matrices. In conclusion, the 60/40 EuRL/TBC binary blend is suitable for the design of transdermal patches since the in vitro permeability of the three selected drugs appeared comparable to those described in literature for marketed products.

In vitro and in vivo evaluation of silk fibroin functionalized with GABA and allopregnanolone for Schwann cell and neuron survival

AIM

This in vitro and in vivo study reports on silk fibroin (SF) scaffold, functionalized for in situ delivery of GABA and/or allopregnanolone (ALLO), as biomaterial for potential application in tissue engineering and nerve regeneration.

MATERIALS & METHODS

We evaluated the feasibility to design 2D scaffolds (films) made of regenerated Bombyx mori SF, functionalized with GABA and/or ALLO to enhance in vitro biological functions, health, survival and growth of Schwann cells and sensitive neurons of the dorsal root ganglia.

RESULTS & CONCLUSION

Our 2D-SF film showed an efficient loading and controllable release of drugs promoting nerve regeneration. SF functionalized film may be helpful for the development of bioengineered conduits and, in principle, have great potential for long-gap nerve injury repair.

Molecular Dynamics as a tool for in silico screening of skin permeability

Prediction of skin permeability can have manifold applications ranging from drug delivery to toxicity prediction. Along with the semi-empirical or mechanistic models proposed in the last decades, Molecular Dynamics simulations have recently become a fruitful tool for investigating membrane permeability, in particular as they allow the involved mechanisms to be modelled at a molecular level. Despite their significant structural complexity, Molecular Dynamics simulations can also be utilized to study permeation through the lipid matrix that characterizes the stratum corneum. In this work, Steered Molecular Dynamics simulations are performed on a suitably developed stratum corneum lipid matrix model. Regardless of their actual tortuous path within the stratum corneum, the permeants, taken from a Fully Validated dataset of 80 compounds of known permeability coefficient, are moved through the bilayer along its normal. This allows the exploration of all the possible conformational and physicochemical constraints the molecule experiences when moving through the bilayer. The so performed Steered Molecular Dynamics simulations are then utilized to extract the corresponding lipophilicity and diffusion parameters as computed by subdividing the entire path in 18 regions of different polarity and composition. Correlative analyses showed that the water-lipids interface is the best performing region and that significant enhancements can be gained by including parameters accounting for the temperature effect. Taken together, the developed models possess an enhanced predictive power compared to the existing equations and statistics are approaching the best possible results, given the uncertainty in the utilized permeability data.

Tuning the Extent and Depth of Penetration of Flexible Liposomes in Human Skin

In this work we made an attempt to assess the effect of drug-induced changes of flexibility on the penetration of deformable vesicles into the human skin. Eight cationic liposomes with different degrees of flexibility were obtained by entrapping unfractionated heparin, enoxaparin, and nadroparin. The deformability was studied by a novel, facile, and reliable extrusion assay appositely developed and validated by means of quantitative nanoscale mechanical AFM measurements of vesicle elastic modulus (log₁₀(YM)). The proposed extrusion assay, determining the forces involved in vesicles deformation, resulted very sensitive to evidence of minimal changes in bilayer rigidity (σ) and vesicle deformation (K). The drug loading caused a reduction of liposome flexibility with respect to the reference plain liposomes and in accordance to the heparin type, drug to cationic lipid (DOTAP) ratio, and drug distribution within the vesicles. Interestingly, the σ and log₁₀(YM) values perfectly correlated (R² = 0.935), demonstrating the reliability of the deformability data obtained with both approaches. The combination of TEM and LC-MS/MS spectrometry allowed the pattern of the penetration of the entire vesicles into the skin to be followed. In all cases, intact liposomes in the epidermis layers were observed and a relationship between the depth of penetration and the liposome flexibility was found, supporting the hypothesis of the whole vesicle penetration mechanism. Moreover, the results of the extent (R₂₄) of vesicle penetration in the human skin samples showed a direct relation to the flexibility values (σ₁ = 0.65 ± 0.10 MPa → R₂₄ = 3.33 ± 0.02 μg/mg; σ₂ = 0.95 ± 0.04 MPa → R₂₄ = 1.18 ± 0.26 μg/mg; σ₃ = 1.89 ± 0.30 MPa → R₂₄ = 0.53 ± 0.33 μg/mg).

Development of nanoemulsions for topical delivery of vitamin K1

Vitamin K1 (VK1) is a natural and lipophilic compound currently used in dermatological formulations. In this work, nanoemulsions containing VK1 have been proposed to overcome some issues associated to semisolid VK1-incorporating formulations. The study has been focused on the design of a lipid-free aqueous formulation, easy to prepare and with low cost of production. Thus, a simply protocol, using a low-energy method, has been used to spontaneously form the nanoemulsions. The nanoemulsion composition has been optimized to improve its physical stability during storage in different conditions. Then, the possibility to administer VK1-containing nanoemulsions by nebulization without significant alteration of the formulation was tested. Moreover, the VK1 accumulation into the skin layers have been evaluated through permeation experiments on Franz cells, ATR-FITR analysis, confocal laser scanning microscopy (CLSM) observations, and high performance liquid chromatography (HPLC) analysis. The study demonstrated that NEs represent an interesting option for the commercial development of an aqueous spray formulation for the topical delivery of VK1.

Supersaturation as a tool for skin penetration enhancement

Supersaturated systems have attracted interest to enhance the skin penetration because of the low cost and reduced risks of irritation with respect to other approaches. The mechanism is simply based on the increased drug driving force for transit out of the dosage form and penetrate the stratum corneum. Supersaturated systems can be obtained by preparation of solvent/non-solvent mixtures; or mixtures containing a skin penetrating solvent or a volatile solvent, and quenching. All methods are described to obtain solutions or semisolid preparations; meanwhile the solvent evaporation and quenching can be used in the transdermal patch production. The adopted formulative strategies can increase the drug concentration in the vehicle 5-fold the solubility and the corresponding increment of the thermodynamic activity determines a significant increase of the drug flux through the skin, according to the Fick's law. The main limitation of supersaturated systems is related to their thermodynamic instability that, leading to drug crystallization in the vehicle, affects the drug skin penetration. Among the possible strategies to avoid or retard this issue the use of polymeric materials appears the most efficacious. However, the crystallization of a drug during storage and/or application on the skin is driven by so many factors that the stability of supersaturated systems is unpredictable. This paper offers a comprehensive review of the literature with the aim to underline the "pros and cons" of the application of supersaturation in transdermal delivery in the light of the theoretical aspects.

On the selection of an opioid for local skin analgesia: Structure-skin permeability relationships

Recent studies demonstrated that post-herpetical and inflammatory pain can be locally managed by morphine gels, empirically chosen. Aiming to rationalize the selection of the most suitable opioid for the cutaneous delivery, we studied the in vitro penetration through human epidermis of eight opioids, evidencing the critical modifications of the morphinan core. Log P, log D, solid-state features and solubility were determined. Docking simulations were performed using supramolecular assembly made of ceramide VI. The modifications on position 3 of the morphinan core resulted the most relevant in determining both physicochemical characteristics and diffusion pattern. The 3-methoxy group weakened the cohesiveness of the crystal lattice structure and increased the permeation flux (J). Computational studies emphasized that, while permeation is essentially controlled by molecule apolarity, skin retention depends on a fine balance of polar and apolar molecular features. Moreover, ChemPLP scoring the interactions between the opioids and ceramide, correlated with both the amount retained into the epidermis (Qret) and J. The balance of the skin penetration properties and the affinity potency for μ-receptors evidenced hydromorphone as the most suitable compound for the induction of local analgesia.