Polymersomes for protein drug delivery across intestinal mucosa.

The oral administration is the route preferred by patients due to its multiple advantages. In the case of biopharmaceuticals, due to their low stability and absorption in the intestine, these molecules must be administered by injectable routes. To circumvent these problems, several strategies have been studied, among which the use of nanosystems, such as polymersomes, can be highlighted. In this work the potential of poloxamer 401 polymersomes as a system for oral delivery of antibodies was evaluated. IgG-FITC-loaded poloxamer 401 polymerosomes were initially used to assess whether it improves intestinal epithelial permeation in Caco-2 cell monolayers. Subsequently, epithelial/macrophage co-culture model was used to evaluate the ability of poloxamer 401 polymersomes containing adalimumab to reduce proinflammatory cytokine levels. The data showed that polymersome-encapsulated IgG increased the transport across intestinal Caco-2 monolayers 2.7-fold compared to the antibody in solution. Also, when comparing the groups of blank polymersomes with polymersomes containing adalimumab, decreases of 1.5-, 5.5-, and 2.4-fold in TNF-α concentrations were observed for the polymersomes containing 1.5, 3.75, and 15 µg/mL of adalimumab, respectively. This could indicate a possibility for the oral administration of biopharmaceuticals which would revolutionize many conditions that require the systemic administration such as in inflammatory bowel disease.

Zein nanoparticles as oral carrier for mometasone furoate delivery.

Mometasone furoate (MF) is a synthetic glucocorticoid used clinically to treat specific inflammatory disorders including superior and inferior respiratory tract. Due to its poor bioavailability we further investigated whether nanoparticles (NPs) made of zein protein may constitute a safe and effective choice to incorporate MF. Thus, in this work, we loaded MF into zein NPs aiming to evaluate possible advantages that could result from oral delivery and extend the range of MF application such as inflammatory gut diseases. MF-loaded zein NPs presented an average size in the range of 100 and 135 nm, narrow size distribution (polydispersity index < 0.300), zeta potential of around + 10 mV and association efficiency of MF over 70%. Transmission electron microscopy imaging revealed that NPs had a round shape and presented a smooth surface. The zein NPs showed low MF release in a buffer that mimics the gastric condition (pH = 1.2) and slower and controlled MF release in the intestinal condition (pH = 6.8). The short and intermediate safety of zein NPs was confirmed assessing the incubation against Caco-2 and HT29-MTX intestinal cells up to 24 h. Permeability studies of MF across Caco-2/HT29-MTX co-culture monolayer evidenced that zein NPs modulated MF transport across cell monolayer resulting in a stronger and prolonged interaction with mucus, potentially extending the time of absorption and overall local and systemic bioavailability. Overall, zein NPs showed to be suitable to carry MF to the intestine and future studies can be developed to investigate the use of MF-loaded zein NPs to treat intestinal inflammatory diseases.

Oral Administration as a Potential Alternative for the Delivery of Small Extracellular Vesicles.

Small extracellular vesicles (sEVs) have burst into biomedicine as a natural therapeutic alternative for different diseases. Considered nanocarriers of biological origin, various studies have demonstrated the feasibility of their systemic administration, even with repeated doses. However, despite being the preferred route of physicians and patients, little is known about the clinical use of sEVs in oral administration. Different reports show that sEVs can resist the degradative conditions of the gastrointestinal tract after oral administration, accumulating regionally in the intestine, where they are absorbed for systemic biodistribution. Notably, observations demonstrate the efficacy of using sEVs as a nanocarrier system for a therapeutic payload to obtain a desired biological (therapeutic) effect. From another perspective, the information to date indicates that food-derived vesicles (FDVs) could be considered future nutraceutical agents since they contain or even overexpress different nutritional compounds of the foods from which they are derived, with potential effects on human health. In this review, we present and critically analyze the current information on the pharmacokinetics and safety profile of sEVs when administered orally. We also address the molecular and cellular mechanisms that promote intestinal absorption and that command the therapeutic effects that have been observed. Finally, we analyze the potential nutraceutical impact that FDVs would have on human health and how their oral use could be an emerging strategy to balance nutrition in people.

Solid dispersions based on chitosan/hypromellose phthalate blends to modulate pharmaceutical properties of zidovudine.

Zidovudine (AZT) has been widely used alone or in combination with other antiretroviral drugs for the treatment of human immunodeficiency virus. Its erratic oral bioavailability necessitates frequent administration of high doses, resulting in severe side effects. In this study, the design of mucoadhesive solid dispersions (SDs) based on chitosan (CS) and hypromellose phthalate (HP) was rationalized as a potential approach to modulate AZT physicochemical and pharmaceutical properties. SDs were prepared at different drug:polymer ratios, using an eco-friendly technique, which avoids the use of organic solvents. Particles with diameter from 56 to 73 µm and negative zeta potentials (-27 to -32 mV) were successfully prepared, achieving high drug content. Infrared spectroscopy revealed interactions between polymers but no interactions between the polymers and AZT. Calorimetry and X-ray diffraction analyses showed that AZT was amorphized into the SDs. The mucoadhesive properties of SDs were evidenced, and the control of AZT release rates from the matrix was achieved, mainly in acid media. The simple, low-cost, and scalable technology proposed for production of SDs as a carrier platform for AZT is an innovative approach, and it proved to be a feasible strategy for modulation the physico-chemical, mucoadhesive, and release properties of the drug.

Bacterioruberin from Haloarchaea plus dexamethasone in ultra-small macrophage-targeted nanoparticles as potential intestinal repairing agent.

Oral administration of antioxidant and anti-inflammatory drugs have the potential to improve the current therapy of inflammatory bowel disease. Success of oral treatments, however, depends on the capacity of drugs to remain structurally stable along the gastrointestinal tract, and on the feasibility of accessing the target cells. Delivering anti-inflammatory and antioxidant drugs to macrophages using targeted nanoparticles, could make treatments more efficient. In this work structural features and in vitro activity of macrophage-targeted nanostructured archaeolipid carriers (NAC) containing the high antioxidant dipolar C50 carotenoid bacterioruberin (BR) plus dexamethasone (Dex): NAC-Dex, are described. Ultra-small (66 nm), -32 mV ζ potential, 1200 µg Dex /ml NAC-Dex, consisted of a compritol and BR core, covered by a shell of sn 2,3 ether linked archaeolipids and Tween 80 (2: 2: 1.2: 3 % w/w) were obtained. NAC-Dex were extensively captured by macrophages and Caco-2 cells and displayed high anti-inflammatory and antioxidant activities on a gut inflammation model made of Caco-2 cells and lipopolysaccharide stimulated THP-1 derived macrophages reducing 65 % and 55 % TNF-α and IL-8 release, respectively and 60 % reactive oxygen species production. NAC-Dex also reversed the morphological changes induced by inflammation and increased the transepithelial electrical resistance, partly reconstituting the barrier function. Activity of BR and Dex in NAC-Dex was partially protected after simulated gastrointestinal digestion, improving the chances of BR-Dex joint activity. Results suggest that oral NAC-Dex deserve further exploration as intestinal barrier repairing agent.

Pharmacokinetic Aspects of Nanoparticle-in-Matrix Drug Delivery Systems for Oral/Buccal Delivery.

Oral route maintains its predominance among the ones used for drug delivery, especially when medicines are self-administered. If the dosage form is solid, therapy gains in dose precision and drug stability. Yet, some active pharmaceutical substances do not present the required solubility, permeability, or release profile for incorporation into traditional matrices. The combination of nanostructured drugs (nanoparticle [NP]) with these matrices is a new and little-explored alternative, which could bring several benefits. Therefore, this review focused on combined delivery systems based on nanostructures to administer drugs by the oral cavity, intended for buccal, sublingual, gastric, or intestinal absorption. We analyzed published NP-in-matrix systems and compared main formulation characteristics, pharmacokinetics, release profiles, and physicochemical stability improvements. The reported formulations are mainly semisolid or solid polymers, with polymeric or lipid NPs and one active pharmaceutical ingredient. Regarding drug specifics, most of them are poorly permeable or greatly metabolized. The few studies with pharmacokinetics showed increased drug bioavailability and, sometimes, a controlled release rate. From our knowledge, the gathered data make up the first focused review of these trendy systems, which we believe will help to gain scientific deepness and future advancements in the field.

Solvent-free synthesis of acetylated cashew gum for oral delivery system of insulin.

Cashew gum (CG) is a biopolymer that presents a favorable chemical environment for structural modifications, which leads to more stable and resistant colloidal systems. The gum was subjected to an acetylation reaction using a fast, simple, solvent-free and low cost methodology. The derivative was characterized by infrared and NMR spectroscopy, elemental analysis, coefficient of solubility and zeta potential. The modified biopolymer was used as a platform for drug delivery systems using insulin as a model drug. Nanoparticles were developed through the technique of polyelectrolytic complexation and were characterized by size, surface charge, entrapment efficiency and gastrointestinal release profile. The nanoparticles presented size of 460 nm with a 52.5% efficiency of entrapment of insulin and the electrostatic stabilization was suggested by the zeta potential of + 30.6 mV. Sustained release of insulin was observed for up to 24 h. The results showed that acetylated cashew gum (ACG) presented potential as a vehicle for sustained oral insulin release.

Nanoemulsion-Enabled Oral Delivery of Novel Anticancer ω-3 Fatty Acid Derivatives.

Lipid-based drugs are emerging as an interesting class of novel anticancer drugs with the potential to target specific cancer cell metabolic pathways linked to their proliferation and invasiveness. In particular, ω-3 polyunsaturated fatty acids (PUFA) derivatives such as epoxides and their bioisosteres have demonstrated the potential to suppress growth and promote apoptosis in triple-negative human breast cancer cells MDA-MB-231. In this study, 16-(4'-chloro-3'-trifluorophenyl)carbamoylamino]hexadecanoic acid (ClFPh-CHA), an anticancer lipid derived from ω-3,17,18-epoxyeicosanoic acid, was formulated as a stable nanoemulsion with size around 150 nm and narrow droplet size distribution (PDI < 0.200) through phase-inversion emulsification process followed by high pressure homogenization in view of an oral administration. The ClFPh-CHA-loaded nanoemulsions were able to significantly decrease the relative tumor volume in mice bearing an intramammary tumor xenograft at all doses tested (2.5, 10 and 40 mg/kg) after 32 days of daily oral administration. Furthermore, absolute tumor weight was decreased to 50% of untreated control at 10 and 40 mg/kg, while intraperitoneal administration could achieve a significant reduction only at the highest dose of 40 mg/kg. Results suggest that oral administration of ClFPh-CHA formulated as a nanoemulsion has a sufficient bioavailability to provide an anticancer effect in mice and that the activity is at least equal if not superior to that obtained by a conventional parenteral administration of equivalent doses of the same drug.

Development of self-nanoemulsifying tablet (SNET) for bioavailability enhancement of sertraline

The purpose of the study was to combine the advantages of self-nanoemulsifying drug delivery systems and tablets as a conventional dosage form. Self-nanoemulsifying drug delivery system (SNEDDS) was prepared to enhance the solubility and thus oral bioavailability of sertraline. Aqueous titration method was used to prepare the liquid SNEDDS; ternary phase diagrams were constructed and based on smaller droplet size (24.8 nm), minimum viscosity (153.63 cP) and polydispersity index (0.182), higher percentage transmittance (95%) and in vitro drug release (97%), an optimum system was designated. Liquid SNEDDS was transformed into free-flowing powder by solid adsorption technique followed by compression into tablets. In vitro release of sertraline from liquid and solid SNEDDS was found to be highly significant compared to plain sertraline (p<0.01). Pharmacokinetic studies after oral administration of liquid and solid SNEDDS in rats showed about 6-and 5-fold increased absorption of sertraline compared to the aqueous suspension of sertraline. These studies demonstrate that the solid SNEDDS are promising strategies for successful delivery of poorly water-soluble drug like sertraline

Ultra-small solid archaeolipid nanoparticles for active targeting to macrophages of the inflamed mucosa.

AIM: Develop nanoparticulate agents for oral targeted delivery of dexamethasone (Dex) to macrophages of inflamed mucosa. MATERIALS & METHODS: Solid archaeolipid nanoparticles (SAN-Dex) (compritol/Halorubrum tebenquichense polar archaeolipids/soybean phosphatidylcholine/Tween-80 4; 0.9; 0.3; 3% w/w) loaded with Dex were prepared. Their mucopenetration, stability under digestion and in vitro anti-inflammatory activity, were determined. RESULTS: Ultra-small SAN-Dex strongly reduced the levels of TNF-α, IL-6 and IL-12 on J774A1 cells stimulated with lipopolysaccharides as compared with free Dex or loaded in ordinary solid lipid nanoparticles-Dex. After in vitro digestion, the anti-inflammatory activity of SAN-Dex was retained, while that of solid lipid nanoparticles-Dex was lost. CONCLUSION: Because of their structural and pharmacodynamic features, SAN-Dex may be suitable for oral targeted delivery to inflamed mucosa.

Engineering Oral and Parenteral Amorphous Amphotericin B Formulations against Experimental Trypanosoma cruzi Infections.

Chagas disease (CD) is a parasitic zoonosis endemic in most mainland countries of Central and South America affecting nearly 10 million people, with 100 million people at high risk of contracting the disease. Treatment is only effective if received at the early stages of the disease. Only two drugs (benznidazole and nifurtimox) have so far been marketed, and both share various limitations such as variable efficacy, many side effects, and long duration of treatment, thus reducing compliance. The in vitro and in vivo efficacy of poly-aggregated amphotericin B (AmB), encapsulated poly-aggregated AmB in albumin microspheres (AmB-AME), and dimeric AmB-sodium deoxycholate micelles (AmB-NaDC) was evaluated. Dimeric AmB-NaDC exhibited a promising selectivity index (SI = 3164) against amastigotes, which was much higher than those obtained for licensed drugs (benznidazole and nifurtimox). AmB-AME, but not AmB-NaDC, significantly reduced the parasitemia levels (3.6-fold) in comparison to the control group after parenteral administration at day 7 postinfection. However, the oral administration of AmB-NaDC (10-15 mg/kg/day for 10 days) resulted in a 75% reduction of parasitemia levels and prolonged the survival rate in 100% of the tested animals. Thus, the results presented here illustrate for the first time the oral efficacy of AmB in the treatment of trypanosomiasis. AmB-NaDC is an easily scalable, affordable formulation prepared from GRAS excipients, enabling treatment access worldwide, and therefore it can be regarded as a promising therapy for trypanosomiasis.

Effect of the oral administration of nanoencapsulated quercetin on a mouse model of Alzheimer's disease.

Quercetin has been identified as a promising compound with a neuroprotective potential against age-related neurodegenerative diseases such as Alzheimer's disease (AD). Nevertheless, the clinical application of quercetin is hampered by its low oral bioavailability. The aim of this work was to evaluate the capability of nanoencapsulated quercetin in zein nanoparticles (NPQ), that significantly improves the oral absorption and bioavailability of the flavonoid, as potential oral treatment for AD. For this purpose, SAMP8 mice were orally treated for two months with either NPQ (25mg/kg every 48h) or a solution of quercetin (Q; 25mg/kg daily). NPQ displayed a size of 260nm and a payload of about 70µg/mg. For Q, no significant effects were observed in animals. On the contrary, the oral administration of NPQ improved the cognition and memory impairments characteristics of SAMP8 mice. These observations appeared to be related with a decreased expression of the hippocampal astrocyte marker GFAP. Furthermore, significant levels of quercetin were quantified in the brain of mice treated with nanoparticles. These findings highlight the potential of zein nanoparticles to promote the oral absorption of quercetin as well as the therapeutic potential of this flavonoid in AD pathogenesis.

A novel "in-feed" delivery platform applied for oral DNA vaccination against IPNV enables high protection in Atlantic salmon (Salmon salar).

BACKGROUND: DNA vaccination has emerged as a promising tool against infectious diseases of farmed fish. Oral delivery allows stress-free administration that is ideal for mass immunization and of paramount importance for infectious pancreatic necrosis (IPN) and other viral disease that affect young salmonids and cause economic losses in aquaculture worldwide. METHODS: We describe the development and in vivo assessment of an "in-feed" formulation strategy for oral immunization with liposomal DNA vaccines, by delivering a vaccine construct coding for an immunogenic region of the VP2 capsid protein. A challenge against IPNV was carried out to determine the vaccine efficacy, by comparing the mortality of pre-smolt Atlantic salmons immunized and non-immunized with the oral vaccine. The antibody response (ELISA) and hematological parameters after immunization were examined, as well as the vaccine effect on the growth and internal structures of fry salmons (histological analysis). The vaccine distribution in the experimental tank after oral administration was investigated by HPLC and PCR amplification. RESULTS: The oral vaccine induced detectable levels of VP2-specific antibodies and conferred significant protection following IPNV challenge, with relative percent survivals (RPS) of 58.2%, for single dose (1mgpDNA/kgfish⋅d), and 66% for double dose (2mgpDNA/kgfish⋅d). We further provide evidence in favour of the vaccine safety to fish and demonstrated absence of pDNA in the tank water, but presence of vaccine residues in faeces and unconsumed feed sediments (solid wastes). CONCLUSION: The delivery platform for liposomal DNA vaccination via feed was successfully proved against IPNV in Atlantic salmon, showing the oral vaccine to be immunogenic and safe for fish, and providing significant protection after oral administration. The "in-feed" technology for oral DNA vaccination holds potential to be applied against IPNV and other pathogens that currently threaten the aquaculture worldwide.

Development and characterization of pullulan-polymethacrylate free films as potential material for enteric drug release

ABSTRACT Free films of pullulan-polymethacrylate associations were produced by casting process to develop a novel target-specific material. For characterization, tests of water vapor permeability, swelling index, infrared absorption spectroscopy, thermogravimetric analysis, scanning electron microscopy and mechanical analysis were performed. The polysaccharide concentration directly influenced vapor permeability and swelling, increasing the values of the latter up to five times when added in a proportion of 20% (per weight). The individual properties of each polymer were maintained, and chemical interactions were not detected. The films were found to be thermally stable and they had unaltered mechanical properties with the addition of the polysaccharide. The microscopic analysis revealed rugosity that was proportional to pullulan and disorganization of the polymer network at pH 6.8. These results suggest that this novel material has potential for enteric drug release because of synergism between pH and enzyme dependence.

In vivo mucoadhesive strength appraisal of gum Manilkara zapota

The mucilage (MMZ) extracted from the seeds of Manilkara zapota(Linn.) P. Royen syn. using maceration techniques was evaluated for mucoadhesive strength by various in vitro and in vivo methods. The result showed that mucoadhesive strength of seeds mucilage have comparable property toward natural and synthetic polymers such as Guar Gum and hydroxyl propyl methyl cellulose (HPMC E5LV) under the experimental conditions used in this study. Briefly, it could be concluded that the seed mucilage of Manilkara zapota can be used as a pharmaceutical excipient in oral mucoadhesive drug delivery systems. Further, it may be appropriate to study the changes in these properties after chemical modifications.

Mucilagem (MMZ) extraída das sementes de Manilkara zapota(Linn.) P. Royen syn utilizando técnicas de maceração foi avaliada por sua força mucoadesiva por vários métodos in vitro e in vivo. O resultado mostrou que a força mucoadesiva das sementes mucilaginosas tem propriedade comparável aos polímeros naturais e sintéticos, tais como goma Guar e hidroxipropilmetil celulose (HPMC E5LV) nas condições experimentais utilizadas neste estudo. Brevemente, se pode concluir que a mucilagem de semente de Manilkara zapota pode ser usada como um excipiente farmacêutico em sistemas de liberação de fármacos mucoadesivos por via oral. Pode ser apropriado o estudo posterior de mudanças nessas propriedades após modificações químicas.

Novel Pullulan-Eudragit® S100 blend microparticles for oral delivery of risedronate: formulation, in vitro evaluation and tableting of blend microparticles.

Polymer blends have been considered a promising strategy to tailor drug release. In order to achieve gastroresistance and controlled release, Pullulan, a polysaccharide, and Eudragit® S100, an enteric polymer were selected to prepare microparticles for oral delivery of risedronate, an antiresorptive drug associated with GI tract injuries. Blend microparticles were prepared by spray-drying technique at 3 Pullulan and Eudragit® S100 ratios (MP2:1, MP1:1 and MP1:2) and were characterized in terms of yield, particle size, encapsulation efficiency, morphology, moisture content, flowability and in vitro drug release profiles. Microparticles presented yields between 31 and 42%, encapsulation efficiencies close to 100%, moisture contents lower than 11%, particle size ranging from 2.9 to 4.8 µm and narrow distribution. In the gastric medium, MP1:2 showed the best gastroresistance profile. In the intestinal fluid, all samples were able to prolong drug release. MP1:2 was compressed into tablets with or without polyvinylpyrrolidone. Both tableted microparticles could be obtained with acceptable average weights, drug content close to 100%, sufficient hardness and low friability. In vitro studies showed that tablets maintained the gastroresistance observed for microparticles and were also able to prolong risedronate release. In conclusion, Pullulan/Eudragit® S100 microparticles are promising alternatives for the oral delivery of risedronate in the future.

In vitro fluoride release and tensile bond Strength of a polymeric intra-buccal bioadhesive / Liberación in vitro de flúor y fuerza de tracción de un bioadhesivo polimérico intra-bucal

The intra-buccal polymeric bioadhesive systems that can stay adhered to the oral soft tissues for drug programmed release, with the preventive and/or therapeutic purpose has been employed for large clinical situations. A system based on hydroxypropyl methyl cellulose/Carbopol 934'/magnesium stearate (HPMC/Cp/StMg) was developed having the sodium fluoride as active principle. This kind of system was evaluated according to its resistance to the removal by means of physical test of tensile strength. Swine buccal mucosa extracted immediately after animals' sacrifice was employed as substrate for the physical trials, to obtain 16 test bodies. Artificial saliva with or without mucin was used to involve the substrate/bioadhesive system sets during the trials. Artificial salivas viscosity was determined by means of Brookfield viscometer, showing the artificial saliva with mucin 10.0 cP, and the artificial saliva without mucin 7.5 cP. The tensile strength assays showed the following averages: for the group "artificial saliva with mucin" - 12.89 Pa, and for the group "without mucin" - 12.35 Pa. Statistical analysis showed no significant difference between the assays for both artificial salivas, and it was possible to conclude that the variable mucin did not interfered with the bioadhesion process for the polymeric devices. The device was able to release fluoride in a safe, efficient and constant way up to 8 hours.

Los sistemas bioadhesivos poliméricos intra-bucales pueden permanecer adheridos a los tejidos blandos orales para una liberación programada de fármacos, con finalidad preventiva y/o propósito terapéutico han sido empleados en diversas situaciones clínicas. Un sistema basado en Hidroxipropilmetilcelulosa/Carbopol934Ô/ estearato de magnesio (HPMC/Cp/StMg) fue desarrollado con fluorato de sodio como principio activo. Este tipo de sistema fue evaluado de acuerdo a su resistencia a la eliminación física por medio de pruebas de resistencia a la tracción. Mucosas bucales de cerdos fueron tomadas inmediatamente después del sacrificio de los animales y se utilizaron como sustrato para las pruebas físicas, obteniendo 16 cuerpos de prueba. Saliva artificial con o sin mucina fue utilizada para participar como parte del sistema sustrato/bioadesivo durante los ensayos. La viscosidad de la saliva artificial, se determinó mediante un viscosímetro Brookfield, mostrando la saliva artificial con mucina 10,0 cP y saliva artificial sin mucina 7,5 cP. Las pruebas de resistencia a la tracción mostraron los siguientes promedios: para la "saliva artificial con mucina" - 12,89 Pa, y para el grupo "sin mucina" - 12,35 Pa. El análisis estadístico no mostró diferencias significativas entre las pruebas de saliva artificial, y es posible concluir que la variable de mucina no interfiere con el proceso de bioadhesión del dispositivo polimérico. El dispositivo fue capaz de liberar fluor de forma segura, eficiente y constante durante un máximo de hasta 8 horas.