Cellular delivery and enhanced anticancer activity of berberine complexed with a cationic derivative of γ-cyclodextrin.

A cationic derivative of γ-cyclodextrin (GCD) modified with propylenediamine (PDA) was synthesized. It was shown that the derivative (GCD-PDA) is mucoadhesive and resistant to the digestion with ∝-amylase indicating that it may constitute an efficient oral delivery vehicle. GCD-PDA formed an inclusion complex with berberine (BBR), an alkaloid displaying a multitude of beneficial physiological effects. The complexed BBR penetrates a lipid membrane easier than the free one. Both uncomplexed BBR and that complexed with GCD-PDA was delivered to normal (NMuMG) and cancerous (4T1) murine mammary gland cells. In the normal cells both free and complexed BBR was homogeneously dispersed in the cytoplasm and was nontoxic up to 131 µM. In the cancerous cells uncomplexed BBR was also homogeneously dispersed but it was toxic to about 25% of cells at 131 µM, while the GCD-PDA/BBR complex was preferably localized in lysosomes and its toxicity doubled at this concentration compared to that of free BBR. Moreover, free BBR and GCD-PDA/BBR showed even more efficient inhibitory effect against murine melanoma (B16-F10) cells than against 4T1 cells.

Investigation of dissolved cellulose in development of buccal discs for oromucosal drug delivery.

Mucoadhesive formulations have a wide scope of application for both systemic and local treatment of various diseases. In the case of recurrent aphthous stomatitis, to ensure effective therapy, the concentration of corticosteroids, and/or anesthetics at the mouth ulcer side should be maintained with minimal systemic absorption. Therefore, the aim of the study was to investigate cellulose-based formulations, in achieving suitable hardness, mucoadhesiveness, and sustained release of the active ingredients directed towards the mucosa for an extended period of time (∼4 h). This was examined by creating polymer reinforced cellulose composites which consisted of porous cellulose discs (CD) and different polymer components namely polyethylene glycol 6000 (PEG6000), polyethylene glycol 400 (PEG400), and ethyl cellulose. Empty CDs were formed by dropping dissolved cellulose into coagulation medium. The empty porous CDs were immersed into different drug loading solutions which were prepared by dissolving three different concentrations of triamcinolone acetonide and lidocaine hydrochloride in five different ratios of PEG 6000:PEG 400:ethanol (w:w:w %) solutions. All formulations were investigated regarding drug content, release, hardness, and mucoadhesive properties. The results indicate that the non-dispersing buccal discs had sufficient hardness, drug content and in vitro release properties, but further studies are needed to achieve proper mucoadhesiveness.

Mucoadhesive plasticized system of branched poly(lactic-co-glycolic acid) with aciclovir.

Commercially available antibacterial semisolid preparations intended for topical application provide only short-term drug release. A sustained kinetics is possible by exploitation of a biodegradable polymer carrier. The purpose of this work is to formulate a mucoadhesive system with aciclovir (ACV) based on a solid molecular dispersion of this drug in poly(lactic-co-glycolic acid) branched on tripenterythritol (PLGA/T). The ACV incorporation into PLGA/T was carried out either by solvent method, or melting method, or plasticization method using various plasticizers. The drug-polymer miscibility, plasticizer efficiency and content of residual solvent were found out employing DSC. Viscosity was measured at the shear rate range from 0.10 to 10.00 s(-1) at three temperatures and data were analyzed by Newtonian model. The mucoadhesive properties were ascertained in the tensile test on a mucin substrate. The amount of ACV released was carried out in a wash-off dissolution test. The DSC results indicate a transformation of crystalline form of ACV into an amorphous dissolved in branched polyester carrier, and absence of methyl formate residuals in formulation. All the tested plasticizers are efficient at Tg depression and viscosity decrease. The non-conventional ethyl pyruvate possessing supportive anti-inflammatory activity was evaluated as the most suitable plasticizer. The ACV release was strongly dependent on the ethyl pyruvate concentration and lasted from 1 to 10 days. The formulated PLGA/T system with ACV exhibits increased adhesion to mucosal hydrophilic surfaces and prolonged ACV release controllable by degradation process and viscosity parameters.

A novel cationic ß-cyclodextrin decorated with a choline-like pendant exhibits Iodophor, Mucoadhesive and bactericidal properties.

Iodine is a vital microelement and a powerful antiseptic with a rapid and broad spectrum of action. The development of iodophor compounds to improve the solubility and stability of iodine is still challenging. Here, we report the synthesis of a novel cationic ß-cyclodextrin bearing a choline-like pendant (ß-CD-Chol) designed to complex and deliver iodine to bacterial cells. The characterization of ß-CD-Chol and the investigation of the inclusion complex with iodine were performed by NMR spectroscopy, mass spectrometry, UV-vis spectrophotometry, isothermal titration calorimetry, and dynamic light scattering. The functionalization with the positively charged unit conferred improved water-solubility, mucoadhesivity, and iodine complexation efficiency to the ß-CD scaffold. The water-soluble ß-CD-Chol/iodine complex efficiently formed both in solution and by solid-vapor reaction. The solid complex exhibited a significant stability for months. Iodine release from the inclusion complex was satisfactory and the bactericidal activity was proved against a Staphylococcus epidermidis strain. The absence of cytotoxicity tested on human keratinocytes and the improved mucoadhesivity make ß-CD-Chol a promising drug delivery system and an appealing iodophor candidate for iodine-based antisepsis including mucosa disinfection.

Synergism of polysaccharide polymers in antihistamine eye drops: Influence on physicochemical properties and in vivo efficacy.

The incorporation of polymers into drug delivery vehicles has been shown to be a useful approach to prolong the residence time of drugs in the precorneal tear film and to improve penetration into biological membranes. The main objective of this research was to formulate novel viscous eye drops with ketotifen as the active ingredient, containing the polysaccharides: chitosan (MCH), hydroxypropyl guar gum (HPG) and hyaluronic acid (SH) alone and in combination as functional polymers. DSC and FT-IR techniques showed the compatibility between ketotifen and polymers. Physicochemical and rheological analysis at ambient and simulated physiological conditions, as well as the evaluation of mucoadhesive properties showed that vehicles containing combinations of polymers have suitable physicochemical and functional properties with demonstrated synergism between combined polymers (MCH and HPG i.e. SH and HPG). The drug permeability was successfully estimated in vitro using HCE-T cell-based models. MTT cytotoxicity assay demonstrates that the tested formulations were non-toxic and well tolerated. In vivo preclinical study on mice revealed that both vehicles containing mixed polymers enhanced and prolonged the antipruritic/analgesic-like effect of ophthalmic ketotifen. Based on these results, both combinations of polysaccharide polymers, especially SH-HPG, could be considered as potential new carriers for ketotifen for ophthalmic use.

Eudragit Films as Carriers of Lipoic Acid for Transcorneal Permeability.

Diabetes mellitus (DM) is a highly prevalent disease affecting almost 10% of the world population; it is characterized by acute and chronic conditions. Diabetic patients have twenty-five times higher risk of going blind and developing cataracts early than the general population. Alpha-lipoic acid (LA) is a highly valuable natural antioxidant for the prevention and treatment of ophthalmic complications, such as diabetic keratopathy and retinopathy. However, its applicability is limited due to its low solubility in water; therefore, suitable systems are required for its formulation. In this work we developed an erodible insert based on Eudragit E100 (E PO) and Lipoic Acid (LA) for the delivery of this compound for the preventive treatment of ocular diseases especially in diabetic patients. Film evaluation was carried out by mechanical and thermal properties, mucoadhesivity, drug release, dynamic light scattering and corneal permeability as the concentration of LA increased. It was shown that upon LA release, it forms nanoparticles in combination with E PO that favor corneal permeation and LA retention in the cornea. These E PO-LA films also resulted non-irritable hence they are promising for their application in the treatment of ocular diseases.

Mucosomes: Intrinsically Mucoadhesive Glycosylated Mucin Nanoparticles as Multi-Drug Delivery Platform.

Mucus is a complex barrier for pharmacological treatments and overcoming it is one of the major challenges faced during transmucosal drug delivery. To tackle this issue, a novel class of glycosylated nanoparticles, named "mucosomes," which are based on the most important protein constituting mucus, the mucin, is introduced. Mucosomes are designed to improve drug absorption and residence time on the mucosal tissues. Mucosomes are produced (150-300 nm), functionalized with glycans, and loaded with the desired drug in a single one-pot synthetic process and, with this method, a wide range of small and macro molecules can be loaded with different physicochemical properties. Various in vitro models are used to test the mucoadhesive properties of mucosomes. The presence of functional glycans is indicated by the interaction with lectins. Mucosomes are proven to be storable at 4 °C after lyophilization, and administration through a nasal spray does not modify the morphology of the mucosomes. In vitro and in vivo tests indicate mucosomes do not induce adverse effects under the investigated conditions. This study proposes mucosomes as a ground-breaking nanosystem that can be applied in several pathological contexts, especially in mucus-related disorders.

Covalently crosslinked organophosphorous derivatives-chitosan hydrogel as a drug delivery system for oral administration of camptothecin.

Hydrogels are widely studied as drug delivery system. In this work we propose the employment of tetrakis(hydroxymethyl)phosphonium chloride as crosslinking agent to obtain covalent hydrogels based on chitosan. These hydrogels are obtained by Mannich reaction between the amino groups of chitosan with the hydroxymethyl groups of the crosslinker molecule. They show a pH sensitive second order swelling kinetic, have low toxicity, are biocompatible, mucoadhesive and allow a modified release of the encapsulated drug, camptothecin, for 48 h. This antitumor drug has been studied as a drug of interest to develop oral chemotherapy administration strategies. According to the obtained results, oral administration of camptothecin through hydrogels would provide low concentrations of drug at the absorption site, avoiding carrier saturation and reducing its intestinal toxicity.

Impact of polyethylene glycol polymers on the physicochemical properties and mucoadhesivity of itraconazole nanoparticles.

Itraconazole (ITR) is a broad-spectrum antifungal drug with a very low solubility. In this work, the application of a heat induced evaporative antisolvent nanoprecipitation process yielded disordered nanoparticles (NPs) of ITR. The inclusion of different types of poly(ethylene glycol) (PEG) allowed PEGylation of NPs by adsorption to be achieved. The NP dispersions were composed of monodispersed particles in a nanometric size range (<290 nm) and although PEGylation had no impact on the average particle size, the surface potential was partially neutralised in the modified NPs. The solid state analysis using powder X-ray diffraction and thermal analysis revealed a disordered, liquid crystalline smectic organisation of the non-PEGylated NPs, while some of the PEGylated NPs were more crystalline. The PEGylated NPs exhibited mucoadhesive potential in stationary conditions (dynamic light scattering analysis) but when flow conditions were applied (nanoparticle tracking analysis and quartz crystal microbalance with dissipation) the particles had mucopenetrative properties. The non-PEGylated ITR NPs did not interact with mucin and therefore, this system was considered as having a mucopenetrative character. This study demonstrates that the properties of NPs made of organic drug molecules can be modified by the addition of polymers, which may impact on their interaction with mucin and therefore on their potential systemic absorption.

Buccal Bullfrog (Rana catesbeiana Shaw) Oil Emulsion: A Mucoadhesive System Intended for Treatment of Oral Candidiasis.

Oral candidiasis (OC) is an infectious disease caused by microorganisms of the genus Candida, leading to lesions in the buccal cavity. Its treatment consists of the administration of topical or systemic antifungal agents, which may compromise the patient compliance due to its side effects, highlighting the need for alternative treatments. In this scenario, bullfrog oil, an animal oil composed of a pool of saturated and unsaturated fatty acids, is introduced as a potential antifungal raw material. Thus, the aim of this work was to produce a mucoadhesive emulsified system able to deliver the bullfrog oil in the buccal cavity to treat the OC. The emulsion was produced and characterized by visual inspection, droplet size, polydispersity index (PdI), and zeta potential over the course of 60 days. In addition, its mucoadhesive ability was evaluated using an in vitro mucin model. The antifungal activity, evaluated by the broth microdilution assay and the biocompatibility, performed against human erythrocytes, were also carried out. The emulsion showed a droplet size of 320.79 ± 35.60 nm, a PdI of 0.49 ± 0.08, and a zeta potential of -38.53 ± 6.23 mV, with no significant changes over 60 days. The mucoadhesive properties of the system was improved by the use of pharmaceutical excipients. The antifungal activity showed that the bullfrog oil and the emulsion were able to inhibit the growth of different Candida species. Furthermore, the emulsion showed no significant hemolytic effect. Overall, the system showed suitable physicochemical characteristics and biocompatibility, with substantial in vitro antifungal activity, suggesting that this system can be further investigated for OC treatment.

Poly-ε-caprolactone/Chitosan and Chitosan Particles: Two Recombinant Antigen Delivery Systems for Intranasal Vaccination.

Several evidences converge on the idea that among the mucosal administration routes, the nasal mucosa is the most attractive site for the delivery of vaccines. Mucoadhesive particulate adjuvants should be able to increase the residence time of antigens in nasal cavity in order to increase their probability of being taken up by nasopharynx-associated lymphoid tissue (NALT) cells and subsequently to initiate the innate and adaptive immune response. Focusing on chitosan, a mucoadhesive biopolymer, we describe in this chapter a method to prepare antigen loaded chitosan nanoparticles and a second method to prepare antigen loaded poly-ε-caprolactone/chitosan nanoparticles. Additionally the methodology for the assessment of mucoadhesivity of the delivery system is also described. The two critical procedures in mice intranasal immunization experiments include challenges in the intranasal administration itself due to the small mouse nose, and the other is related with the collection of mucosal secretions to assess the sIgA. The techniques are difficult to perform without advanced training. Therefore, protocols followed in our laboratory, as well as some tips, are described in this chapter.

Study of sodium hyaluronate-based intranasal formulations containing micro- or nanosized meloxicam particles.

This article reports on the micro- and nanonization of meloxicam (MEL) with the aim of developing pre-dispersions as intermediates for the design of intranasal formulations. As a new approach, combined wet milling technology was developed in order to reduce the particle size of the MEL. Different milling times resulted in micro- or nanosized MEL in the pre-dispersions with polyvinyl alcohol as stabilizer agent, which were directly used for preparing intranasal liquid formulations with the addition of sodium hyaluronate as mucoadhesive agent. Reduction of the MEL particle size into the nano range led to increased saturation solubility and dissolution velocities, and increased adhesiveness to surfaces as compared with microsized MEL particles. A linear correlation was demonstrated between the specific surface area of MEL and the AUC. The in vitro and in vivo studies indicated that the longer residence time and the uniform distribution of nano MEL spray throughout an artificial membrane and the nasal mucosa resulted in better diffusion and a higher AUC. Nanosized MEL may be suggested for the development of an innovative dosage form with a different dose of the drug, as a possible administration route for pain management.

Calcium alginate-carboxymethyl cellulose beads for colon-targeted drug delivery.

The present study delineates preparation, characterization and application of calcium alginate (CA)-carboxymethyl cellulose (CMC) beads for colon-specific oral drug delivery. Here, we exploited pH responsive swelling, mucoadhesivity and colonic microflora-catered biodegradability of the formulations for colon-specific drug delivery. The CA-CMC beads were prepared by ionic gelation method and its physicochemical characterization was done by SEM, XRD, EDAX, DSC and texture analyzer. The swelling and mucoadhesivity of the beads was found higher at the simulated colonic environment. Variation was more prominent in compositions with lower CMC concentrations. CA-CMC formulations degraded slowly in simulated colonic fluid, however the degradation rate increased drastically in the presence of colonic microflora. In vitro release study of anticancer drug 5-fluorouracil (5-FU) showed a release (>90%) in the presence of colonic enzymes. A critical analysis of drug release profile along with FRAP (fluorescence recovery after photobleaching) study revealed that the presence of CMC in the formulation retarded the release rate of 5-FU. 5-FU-loaded formulations were tested against colon adenocarcinoma cells (HT-29). Cytotoxicity data, nuclear condensation-fragmentation and apoptosis analysis (by flow cytometry) together confirmed the therapeutic potential of the CA-CMC formulations. In conclusion, CA-CMC beads can be used for colon-specific drug delivery.