Mucoadhesive Alginate/Pectin Films Crosslinked by Calcium Carbonate as Carriers of a Model Antifungal Drug-Posaconazole

The mucosal membrane of the oral cavity, due to its unique structure and availability, constitutes an appropriate site for the delivery of drugs, both with local and systemic effects. Mucoadhesive buccal films are drug dosage forms that due to their convenience of application, flexibility and size, are characterized by patients' compliance. Sodium alginate and pectin are natural polymers from the polysaccharides group, with mucoadhesive properties, that are widely applied to obtain buccal films. However, their hydrophilic nature and poor water resistance limit their application in sustained drug release formulations. Hence, the aim of this investigation was to design alginate/pectin buccal films by a one-step crosslinking technique-with the application of calcium carbonate. This technique was applied to prepare crosslinked alginate and alginate/pectin mucoadhesive films with a model antifungal drug-posaconazole. The obtained formulations were evaluated for the impact of crosslinking and pectin's presence on their pharmaceutical, mucoadhesive, mechanical and physicochemical properties. Additionally, the antifungal activity of the prepared films against Candida spp. was evaluated. It was shown that pectin's presence in the formulations improved flexibility, mucoadhesion and antifungal activity. The crosslinking process reduced mucoadhesiveness and antifungal activity but significantly enhanced the mechanical properties and stability and enabled prolonged drug release.

The Impact of Hypromellose on Pharmaceutical Properties of Alginate Microparticles as Novel Drug Carriers for Posaconazole

Fungal infections are a group of diseases which are challenging to treat because of drug-resistant fungi species, drug toxicity, and often severe patient conditions. Hence, research into new treatments, including new therapeutic substances and novel drug delivery systems, is being performed. Mucoadhesive dosage forms are beneficial to improving drug bioavailability by prolonging the residence time at the site of application. Sodium alginate is a natural polymer with favorable mucoadhesive and gelling properties, although its precipitation in acidic pH significantly disrupts the process of drug release in gastric conditions. Hypromellose is a hydrophilic, semi-synthetic cellulose derivative with mucoadhesive properties, which is widely used as a control release agent in pharmaceutical technology. The aim of this study was to evaluate the impact of hypromellose on alginate microparticles with posaconazole, designed to modify drug release and to improve their mucoadhesive properties for both oral or vaginal application.

The Spray-Dried Alginate/Gelatin Microparticles with Luliconazole as Mucoadhesive Drug Delivery System

Candida species are opportunistic fungi, which are primary causative agents of vulvovaginal candidiasis. The cure of candidiasis is difficult, lengthy, and associated with the fungi resistivity. Therefore, the research for novel active substances and unconventional drug delivery systems providing effective and safe treatment is still an active subject. Microparticles, as multicompartment dosage forms due to larger areas, provide short passage of drug diffusion, which might improve drug therapeutic efficiency. Sodium alginate is a natural polymer from a polysaccharide group, possessing swelling, mucoadhesive, and gelling properties. Gelatin A is a natural high-molecular-weight polypeptide obtained from porcine collagen. The purpose of this study was to prepare microparticles by the spray-drying of alginate/gelatin polyelectrolyte complex mixture, with a novel antifungal drug-luliconazole. In the next stage of research, the effect of gelatin presence on pharmaceutical properties of designed formulations was assessed. Interrelations among polymers were evaluated with thermal analysis and Fourier transform infrared spectroscopy. A valid aspect of this research was the in vitro antifungal activity estimation of designed microparticles using Candida species: C. albicans, C. krusei, and C. parapsilosis. It was shown that the gelatin addition affected the particles size, improved encapsulation efficiency and mucoadhesiveness, and prolonged the drug release. Moreover, gelatin addition to the formulations improved the antifungal effect against Candida species.

Different Types of Gel Carriers as Metronidazole Delivery Systems to the Oral Mucosa

Periodontal diseases are some of the most widespread oral afflictions, and they are labeled as chronic infections caused by the accumulation of bacteria in dental plaque that produces localized inflammation of the periodontium. The use of local drug delivery systems to treat periodontal diseases has received greater attention, because the active substance is targeted directly to the affected area, which minimizes its systemic side effects. Therefore, the purpose of the investigation was to develop and characterize different types of gel formulations-bigel, hydrogel and oleogel-as local delivery systems containing metronidazole (MET), which can be applied to the oral mucosa. The influence of the formulation type on the mechanical, rheological and mucoadhesive properties were examined. Moreover, in vitro release of metronidazole, its ex vivo permeation through buccal porcine mucosa and antimicrobial activity measured by the plate diffusion method were estimated. It was found that the gel formulations obtained were non-Newtonian systems, showing a shear-thinning behavior and thixotropic properties with good textural features such as firmness, compressibility and adhesiveness. Moreover, the preparations designed possessed beneficial mucoadhesive properties. The formulated hydrogels and bigels containing micronized MET were considered as better formulations in terms of drug release and antimicrobial activity compared to commercially available metronidazole ointment. An ex vivo permeation study with the use of porcine buccal mucosa demonstrated that the bigel formulation was characterized by higher initial permeability rate providing a fast therapeutic effect with simultaneous moderate retention in mucosal tissue to decrease the risk of local cytotoxicity.

In vivo anti-inflammatory and anti-allergic activities of cynaroside evaluated by using hydrogel formulations

OBJECTIVES

Cynaroside (CYN) is the predominant derivative of luteolin in aerial parts of Bidens tripartita which has been used in folk medicine as a diaphoretic, diuretic, antiseptic and anti-inflammatory agent. In our study, alginate (ALG), which is an anionic polymer with bioadhesive properties, was used as a CYN carrier, and multiple hydrogel formulations were created. Additionally, the present study evaluated the in vivo anti-inflammatory and anti-allergic activities of all preparations.

METHODS

Novel gel formulations as topical carriers for CYN obtained from B. tripartita were developed and characterized. The bioadhesive properties of the designed preparations were also evaluated in an ex vivo model using the skin of hairless mice. In vitro CYN release from all formulations was examined and analysed by HPLC. Histopathological evaluation of mouse skin sections stained with H&E after carrageenan and oxazolone administration was also carried out. In addition, the influence of CYN on cell proliferation was examined by the PCNA staining method.

RESULTS

The results showed that 10 % CYN inhibited the release of anti-inflammatory mediators, and both tested concentrations, which included 5 % and 10 % (2 mg and 20 mg CYN per site, respectively), reduced oxazolone-induced ear swelling. Histopathological examination of the samples revealed a marked reduction in paw skin and ear tissue inflammation and in inflammatory infiltrates. The influence of CYN on cell proliferation was examined by the PCNA staining method, and the staining and distribution of PCNA-immunoreactive (PCNA-IR) cells were observed. After the application of the 5 % and 10 % hydrogels, the investigated samples showed decreased nuclear immunoreactivity to PCNA, which was similar to that of the control. Moreover, after application of the placebo formulation, fewer PCNA-IR cells were also observed.

CONCLUSION

The obtained data suggest that the topical application of CYN significantly reduces the number of T cells, mast cells and histiocytes in mouse skin with inflammation or atopic dermatitis.

Development, characterisation and nasal deposition of melatonin-loaded pectin/hypromellose microspheres

In this study, we present the development of spray-dried pectin/hypromellose microspheres as efficient melatonin carrier for targeted nasal delivery. Different pectin to hypromellose weight ratios in the spray-dried feed were employed (i.e. 1:0, 3:1, 1:1 and 1:3) in order to optimise microsphere physicochemical properties influencing overall powder behaviour prior, during and upon nasal delivery. All microspheres assured complete melatonin entrapment and increased dissolution rate in relation to pure melatonin powder. Among all combinations tested, combining pectin with hypromellose at 1:3 wt ratio resulted in the microspheres with the highest potential for melatonin nasal delivery as they assured highest swelling ability and most prominent mucoadhesive properties. Studies on deposition profile revealed adequate turbinate and olfactory deposition of microsphere/lactose monohydrate powder blend administered nasally using MIAT® device, complementing findings relevant for their therapeutic potential. In conclusion, developed microspheres bear the potential to ensure prolonged melatonin retention at the nasal mucosa, improved bioavailability and advanced therapeutic outcome.

Possibilities of Fucoidan Utilization in the Development of Pharmaceutical Dosage Forms

Fucoidan is a polysaccharide built from L-fucose molecules. The main source of this polysaccharide is the extracellular matrix of brown seaweed (Phaeophyta), but it can be also isolated from invertebrates such as sea urchins (Echinoidea) and sea cucumbers (Holothuroidea). Interest in fucoidan is related to its broad biological activity, including possible antioxidant, anti-inflammatory, antifungal, antiviral or antithrombotic effects. The potential application of fucoidan in the pharmaceutical technology is also due to its ionic nature. The negative charge of the molecule results from the presence of sulfate residues in the C-2 and C-4 positions, occasionally in C-3, allowing the formation of complexes with other oppositely charged molecules. Fucoidan is non-toxic, biodegradable and biocompatible compound approved by Food and Drug Administration (FDA) as Generally Recognized As Safe (GRAS) category as food ingredient. Fucoidan plays an important role in the pharmaceutical technology, so in this work aspects concerning its pharmaceutical characteristics and designing of various dosage forms (nanoparticles, liposomes, microparticles, and semisolid formulations) with fucoidan itself and with its combinations with other polymers or components that give a positive charge were reviewed. Advantages and limitations of fucoidan utilization in the pharmaceutical technology were also discussed.

Ethylcellulose in Organic Solution or Aqueous Dispersion Form in Designing Taste-Masked Microparticles by the Spray Drying Technique with a Model Bitter Drug: Rupatadine Fumarate

The taste of drugs is an important factor affecting pharmacotherapy effectiveness, and obtaining formulations with acceptable organoleptic properties is still an ongoing issue in pharmaceutical technology. One of the innovative methods of taste masking is preparation of microparticles by the spray drying technique, utilizing polymers with different physicochemical properties. Rupatadine fumarate (RUP) is one of the newest antihistamines, with an innovative and multidirectional mechanism of action, and an extremely bitter taste. The aim of this work was to investigate the feasibility of utilizing organic or aqueous forms of ethylcellulose (EC) for the preparation of microparticles with RUP by the spray drying technique. Spray dried samples at different drug:polymer ratios were prepared using organic solution (Ethocel^®) or aqueous dispersions of EC (Surelease^®, Aquacoat^® ECD). Evaluation of the taste masking efficacy was performed in vivo in human taste panel, in vitro based on dissolution test, and by self-constructed electronic tongue. It was shown that microparticles obtained from aqueous dispersions of EC have superior pharmaceutical properties in terms of both morphology and taste masking efficacy in comparison to those obtained from organic solution.

Nanostructured lipid carriers: A potential use for skin drug delivery systems

Skin application of pharmaceutical products is one of the methods used for drug administration. The problem of limited drug penetration via topical application makes searching for safe drug carriers that will provide an expected therapeutic effect of utmost importance. Research into safe drug carriers began with liposome structures, paving the way for work with nanocarriers, which currently play a large role as drug vehicles. Nanostructured lipid carriers (NLC) consist of blended solid and liquid lipids (oils) dispersed in an aqueous solution containing a surfactant. These carriers have many advantages: good biocompatibility, low cytotoxicity, high drug content; they enhance a drug's stability and have many possibilities of application (oral, intravenous, pulmonary, ocular, dermal). The following article presents properties, methods of preparation and tests to assess the quality and toxicity of NLC. This analysis indicates the possibility of using NLC for dermal and transdermal drug application.

Calcium Chloride Modified Alginate Microparticles Formulated by the Spray Drying Process: A Strategy to Prolong the Release of Freely Soluble Drugs

Alginate (ALG) cross-linking by CaCl₂ is a promising strategy to obtain modified-release drug delivery systems with mucoadhesive properties. However, current technologies to produce CaCl₂ cross-linked alginate microparticles possess major disadvantages, such as a poor encapsulation efficiency of water-soluble drugs and a difficulty in controlling the process. Hence, this study presents a novel method that streamlines microparticle production by spray drying; a rapid, continuous, reproducible, and scalable technique enabling obtainment of a product with low moisture content, high drug loading, and a high production yield. To model a freely water-soluble drug, metformin hydrochloride (MF) was selected. It was observed that MF was successfully encapsulated in alginate microparticles cross-linked by CaCl₂ using a one-step drying process. Modification of ALG provided drug release prolongation-particles obtained from 2% ALG cross-linked by 0.1% CaCl₂ with a prolonged MF rate of dissolution of up to 12 h. Cross-linking of the ALG microparticles structure by CaCl₂ decreased the swelling ratio and improved the mucoadhesive properties which were evaluated using porcine stomach mucosa.

Original research paper. Characterization and taste masking evaluation of microparticles with cetirizine dihydrochloride and methacrylate-based copolymer obtained by spray drying

Taste of a pharmaceutical formulation is an important parameter for the effectiveness of pharmacotherapy. Cetirizine dihydrochloride (CET) is a second-generation antihistamine that is commonly administered in allergy treatment. CET is characterized by extremely bitter taste and it is a great challenge to successfully mask its taste; therefore the goal of this work was to formulate and characterize the microparticles obtained by the spray drying method with CET and poly(butyl methacrylate-co-(2-dimethylaminoethyl) methacrylate-co-methyl methacrylate 1:2:1 copolymer (Eudragit E PO) as a barrier coating. Assessment of taste masking by the electronic tongue has revealed that designed formulations created an effective taste masking barrier. Taste masking effect was also confirmed by the in vivo model and the in vitro release profile of CET. Obtained data have shown that microparticles with a drug/polymer ratio (0.5:1) are promising CET carriers with efficient taste masking potential and might be further used in designing orodispersible dosage forms with CET.

The Influence of Chitosan Cross-linking on the Properties of Alginate Microparticles with Metformin Hydrochloride-In Vitro and In Vivo Evaluation

Sodium alginate is a polymer with unique ability to gel with different cross-linking agents in result of ionic and electrostatic interactions. Chitosan cross-linked alginate provides improvement of swelling and mucoadhesive properties and might be used to design sustained release dosage forms. Therefore, the aim of this research was to develop and evaluate possibility of preparing chitosan cross-linked alginate microparticles containing metformin hydrochloride by the spray-drying method. In addition, influence of cross-linking agent on the properties of microparticles was evaluated. Formulation of microparticles prepared by the spray drying of 2% alginate solution cross-linked by 0.1% chitosan was characterized by good mucoadhesive properties, high drug loading and prolonged metformin hydrochloride release. It was shown that designed microparticles reduced rat glucose blood level, delayed absorption of metformin hydrochloride and provided stable plasma drug concentration. Additionally, histopathological studies of pancreas, liver and kidneys indicated that all prepared microparticles improved degenerative changes in organs of diabetic rats. Moreover, no toxicity effect and no changes in rats behavior after oral administration of chitosan cross-linked alginate microparticles were noted.

PREPARATION AND CHARACTERIZATION OF ORALLY DISINTEGRATING LORATADINE TABLETS MANUFACTURED WITH CO-PROCESSED MIXTURES

The aim of this study was to develop orally disintegrated tablets (ODT) with loratadine using Parteck ODT and Ludiflash--new commercially available tableting excipients based on co-processed mannitol. ODT containing loratadine were prepared with 3% addition of various superdisintegrants (AcDiSol, Kollidon CL-F and Kollidon CL-SF) by direct compression method. Obtained tablets were characterized for friability, pore structure, and wetting and disintegration time measured by four independents methods. In order to identify possible interactions between loratadine and the excipients, differential scanning calorimetry was used. The results showed that all formulated ODT were characterized by appropriate mechanical properties (friability < 1%), the uniform content of the drug substance and pleasant mouth feeling. Disintegration time below 30 s was observed in formulations with crospovidones as disintegrant.

EVALUATION OF ALGINATE MICROSPHERES WITH METRONIDAZOLE OBTAINED BY THE SPRAY DRYING TECHNIQUE

In the present study, nine formulations (F1-F9) of alginate microspheres with metronidazole were prepared by the spray drying technique with using different drug:polymer ratio (1:2, 1:1, 2:1) and different sodium alginate concentration (1, 2, 3%). The obtained microspheres were characterized for size, morphology, drug loading, (potential and swelling degree. Mucoadhesive properties were examined using texture analyzer and three different models of adhesive layers--gelatin discs, mucin gel and porcine vaginal mucosa. In vitro drug release, mathematical release profile and physical state of microspheres were also evaluated. The obtained results indicate that sodium alginate is a suitable polymer for developing mucoadhesive dosage forms of metronidazole. The optimal formulation F3 (drug:polymer ratio 1:2 and 1% alginate solution) was characterized by the highest metronidazole loading and sustained drug release. The results of this study indicate promising potential of ALG microspheres as alternative dosage forms for metronidazole delivery.

Alginate microspheres obtained by the spray drying technique as mucoadhesive carriers of ranitidine

The present study is aimed at formulation of alginate (ALG) microspheres with ranitidine (RNT) by the spray drying method. Obtained microspheres were characterized for particle size, surface morphology, entrapment efficiency, drug loading, in vitro drug release and zeta potential. Mucoadhesive properties were examined by a texture analyser and three types of adhesive layers--gelatine discs, mucin gel and porcine stomach mucosa. Microspheres showed a smooth surface with narrow particle size distribution and RNT loading of up to 70.9%. All formulations possessed mucoadhesive properties and exhibited prolonged drug release according to the first-order kinetics. DSC reports showed that there was no interaction between RNT and ALG. Designed microspheres can be considered potential carriers of ranitidine with prolonged residence time in the stomach.