Surface Modification of Titanate Nanotubes with a Carboxylic Arm for Further Functionalization Intended to Pharmaceutical Applications.

Nanotechnology is playing a significant role in modern life with tremendous potential and promising results in almost every domain, especially the pharmaceutical one. The impressive performance of nanomaterials is shaping the future of science and revolutionizing the traditional concepts of industry and research. Titanate nanotubes (TNTs) are one of these novel entities that became an appropriate choice to apply in several platforms due to their remarkable properties such as preparation simplicity, high stability, good biocompatibility, affordability and low toxicity. Surface modification of these nanotubes is also promoting their superior characters and contributing more to the enhancement of their performance. In this research work, an attempt was made to functionalize the surface of titanate nanotubes with carboxylic groups to increase their surface reactivity and widen the possibility of bonding different molecules that could not be bonded directly. Three carboxylic acids were investigated (trichloroacetic acid, citric acid and acrylic acid), and the prepared composites were examined using FT-IR and Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS). The toxicity of these functionalized TNTs was also investigated using adherent cancer cell lines and fibroblasts to determine their safety profile and to draw the basic lines for their intended future application. Based on the experimental results, acrylic acid could be the suitable choice for permanent surface modification with multiple carboxylic groups due to its possibility to be polymerized, thus presenting the opportunity to link additional molecules of interest such as polyethylene glycol (PEG) and/or other molecules at the same time.

Quality by Design-Guided Systematic Development and Optimization of Mucoadhesive Buccal Films.

Mucoadhesive buccal films have found increased popularity in pharmaceutical drug delivery due to the several advantages that they possess. The present study strives to develop and optimize chitosan-based mucoadhesive buccal films by relying on quality-by-design (QbD) principles. Previous knowledge and experience were employed to firstly identify the critical quality attributes (CQAs), followed by a thorough risk assessment, which led to the selection of seven critical material attributes and process parameters, namely, the polymer grade and concentration, the plasticizer type and concentration, the citric acid (CA) concentration, the amount of the casted solution, and the drying condition. Their effects on the breaking hardness and mucoadhesivity, selected as CQAs, were investigated in three steps by three designs of the experiment (DoE). The medium molecular weight of chitosan (CH) was the preferred choice in the optimized formulation, and its concentration was the most important factor affecting the CQAs, thickness, and moisture content of the films. It was found that 0.364 g/cm2 was the suitable amount of the casting solution, and its optimum drying conditions were presented in the form of a design space. Glycerol (Gly) was the best choice as a plasticizer, and a design space representing several combinations of CH and CA concentrations that produce films with the required quality was constructed at a fixed concentration of 35% Gly. A formula from this design space was selected and employed to load with two model drugs to test its drug-carrying properties for drugs with different physicochemical characteristics. Uniform drug distribution with an immediate release profile was achieved in both drugs, although one of the CQAs was outside of the specifications in the case of lidocaine-containing film. To summarize, the obtention of the optimum mucoadhesive buccal film based on CH was efficiently facilitated by the rational application of QbD principles and the DoE approach.

Formulation and characterization of pramipexole containing buccal films for using in Parkinson's disease.

Parkinson's disease (PD) is neurodegenerative chronic illness which affects primarily the elderly over 45 years of age. The symptoms can be various, both non-motor and motor symptoms can appear. The biggest problem in the treatment of the disease is the difficulty in swallowing for the patients. However, buccal patches can solve this problem because the patients do not have to swallow the dosage form, and during application, the API can absorb from the area of the buccal mucosa quickly without causing a foreign body sensation. In our present study, we focused on the development of buccal polymer films with pramipexole dihydrochloride (PR). Films with different compositions were formulated and their mechanical properties and chemical interactions were investigated. The biocompatibility of the film compositions was examined on the TR146 buccal cell line. The permeation of PR was also monitored across the TR146 human cell line. It can be stated that the plasticizer can enhance the thickness and the breaking hardness of the films, while not decreasing their mucoadhesivity significantly. All formulations proved to have cell viability higher than 87%. Finally, we found the best composition (3% SA+1% GLY-PR-Sample1) which can be applied on the buccal mucosa in the treatment of PD.

Quality by Design-Based Development of Solid Self-Emulsifying Drug Delivery System (SEDDS) as a Potential Carrier for Oral Delivery of Lysozyme.

For many years, researchers have been making efforts to find a manufacturing technique, as well as a drug delivery system, that will allow for oral delivery of biopharmaceuticals to their target site of action without impairing their biological activity. Due to the positive in vivo outcomes of this formulation strategy, self-emulsifying drug delivery systems (SEDDSs) have been intensively studied in the last few years as a way of overcoming the different challenges associated with the oral delivery of macromolecules. The purpose of the present study was to examine the possibility of developing solid SEDDSs as potential carriers for the oral delivery of lysozyme (LYS) using the Quality by Design (QbD) concept. LYS was successfully ion paired with anionic surfactant, sodium dodecyl sulphate (SDS), and this complex was incorporated into a previously developed and optimized liquid SEDDS formulation comprising medium-chain triglycerides, polysorbate 80, and PEG 400. The final formulation of a liquid SEDDS carrying the LYS:SDS complex showed satisfactory in vitro characteristics as well as self-emulsifying properties (droplet size: 13.02 nm, PDI: 0.245, and zeta potential: -4.85 mV). The obtained nanoemulsions were robust to dilution in the different media and highly stable after 7 days, with a minor increase in droplet size (13.84 nm) and constant negative zeta potential (-0.49 mV). An optimized liquid SEDDS loaded with the LYS:SDS complex was further solidified into powders by adsorption onto a chosen solid carrier, followed by direct compression into self-emulsifying tablets. Solid SEDDS formulations also exhibited acceptable in vitro characteristics, while LYS preserved its therapeutic activity in all phases of the development process. On the basis of the results gathered, loading the hydrophobic ion pairs of therapeutic proteins and peptides to solid SEDDS may serve as a potential method for delivering biopharmaceuticals orally.

Development and evaluation of bioadhesive buccal films based on sodium alginate for allergy therapy.

Buccal drug administration is a less explored area, therefore researchers and companies focus on its research because of its innovative potential and opportunities. Buccal polymer films (patches) are considered to be an innovative form and have a great number of advantageous properties. Firstly, patients who suffer from swallowing problems and children can also apply them. The active pharmaceutical ingredient enters the systemic circulation directly without degradation and transformation. The aim of this study was to formulate buccal films with sodium alginate (SA) because it is a rarely used, innovative polymer for the formulation of buccal films. The mechanical, chemical properties and dosage forms of the prepared films were investigated with different methods. To formulate the films, cetirizine dihydrochloride (CTZ) was used as model drug, and glycerol (GLY) was added to make the films more elastic. The samples were prepared and stored at room temperature. As a result, it can be seen that the mechanical properties of all film compositions show good results, especially breaking hardness. The films with high SA concentration containing CTZ had appropriate mucoadhesion forces, so these samples are suitable for application on the buccal mucosa. The results of dissolution confirmed this finding. Finally, it can be said we formulated fast dissolving films and it can be concluded that the films prepared with 3% SA concentration containing 1% and 3% GLY can be recommended for buccal application.

Stability, Permeability and Cytotoxicity of Buccal Films in Allergy Treatment.

Oral mucoadhesive systems, such as polymer films, are among innovative pharmaceutical products. These systems can be applied in swallowing problems and can also be used in geriatrics and paediatrics. In our earlier work, we successfully formulated buccal mucoadhesive polymer films, which contained cetirizine-hydrochloride (CTZ) as the API. The present study focused on investigating the stability and permeability of the prepared films. The stability of the films was studied with an accelerated stability test. During the stability test, thickness, breaking hardness and in vitro mucoadhesivity were analysed. Furthermore, the interactions were studied with FT-IR spectroscopy, and the changes in the amount of the API were also monitored. Cytotoxicity and cell line permeability studies were carried out on TR 146 buccal cells. Compositions that can preserve more than 85% of the API after 6 months were found. Most of the compositions had a high cell viability of more than 50%. Citric acid (CA) decreased the stability and reduced every physical parameter of the films. However, cell line studies showed that the permeability of the films was enhanced. In our work, we successfully formulated CTZ-containing buccal films with adequate stability, high cell viability and appropriate absorption properties.

Investigation of the Drug Carrier Properties of Insoluble Cyclodextrin Polymer Microspheres.

The investigation of the usability of solid insoluble ß-cyclodextrin polymers (ßCDP) in micro-sized, controlled drug delivery systems has only recently attracted interest. Our aim was to form complexes with poorly soluble active pharmaceutical ingredients (APIs) with two types of ßCDP for drug delivery applications. Solid insoluble cyclodextrin polymer of irregular shape (ßCDPIS) and cyclodextrin microbeads (ßCDPB) were used in the experiments. Morphology, surface area, size distribution and swelling capacity of carriers were investigated. We created complexes with two APIs, curcumin and estradiol, and applied powder X-ray diffraction, FTIR and thermal analysis (TGA/DSC) to prove the complexation. Finally, the dissolution, biocompatibility and permeation of APIs on Caco-2 cells were investigated. The size of the beads was larger than 100 µm, their shape was spherical and surfaces were smooth; while the ßCDPIS particles were around 4 µm with irregular shape and surface. None of the polymers showed any cytotoxic effect on Caco-2 cells. Both carriers were able to extract curcumin and estradiol from aqueous solutions, and the dissolution test showed prolonged estradiol release. Caco-2 permeability tests were in accordance with the complexation abilities and dissolution of the complexes. This study offers useful data for further pharmaceutical applications of insoluble cyclodextrin polymers.

Predicting Drug Release Rate of Implantable Matrices and Better Understanding of the Underlying Mechanisms through Experimental Design and Artificial Neural Network-Based Modelling.

There is a growing interest in implantable drug delivery systems (DDS) in pharmaceutical science. The aim of the present study is to investigate whether it is possible to customize drug release from implantable DDSs through drug-carrier interactions. Therefore, a series of chemically similar active ingredients (APIs) was mixed with different matrix-forming materials and was then compressed directly. Compression and dissolution interactions were examined by FT-IR spectroscopy. Regarding the effect of the interactions on drug release kinetics, a custom-made dissolution device designed for implantable systems was used. The data obtained were used to construct models based on artificial neural networks (ANNs) to predict drug dissolution. FT-IR studies confirmed the presence of H-bond-based solid-state interactions that intensified during dissolution. These results confirmed our hypothesis that interactions could significantly affect both the release rate and the amount of the released drug. The efficiencies of the kinetic parameter-based and point-to-point ANN models were also compared, where the results showed that the point-to-point models better handled predictive inaccuracies and provided better overall predictive efficiency.

Investigation of Surface Properties and Free Volumes of Chitosan-Based Buccal Mucoadhesive Drug Delivery Films Containing Ascorbic Acid.

Nowadays, the buccal administration of mucoadhesive films is very promising. Our aim was to prepare ascorbic acid-containing chitosan films to study the properties and structures important for applicability and optimize the composition. During the formulation of mucoadhesive films, chitosan as the polymer basis of the film was used. Ascorbic acid, which provided the acidic pH, was used in different concentrations (2-5%). The films were formulated by the solvent casting method. The properties of films important for applicability were investigated, such as physical parameters, mucoadhesive force, surface free energy, and breaking strength. The fine structure of the films was analyzed by atomic force microscopy, and the free volume was analyzed by PALS, which can be important for drug release kinetics and the location of the drug in the film. The applicability of the optimized composition was also tested with two different types of active ingredients. The structure of the films was also analyzed by XRPD and FTIR. Ascorbic acid can be used well in chitosan films, where it can function as a permeation enhancer when reacting to chitosan, it is biodegradable, and can be applied in 2% of our studies.

Manufacturing and Examination of Vaginal Drug Delivery System by FDM 3D Printing.

Vaginal drug delivery systems can provide a long-term and constant liberation of the active pharmaceutical ingredient even for months. For our experiment, FDM 3D printing was used to manufacture the vaginal ring samples from thermoplastic polyurethane filament, which enables fast manufacturing of complex, personalized medications. 3D printing can be an excellent alternative instead of industrial manufacturing, which is complicated and time-consuming. In our work, the 3D printed vaginal rings were filled manually with jellified metronidazole or chloramphenicol for the treatment of bacterial vaginosis. The need for manual filling was certified by the thermogravimetric and heatflow assay results. The manufactured samples were analyzed by an Erweka USP type II Dissolution Apparatus, and the dissolution profile can be distinguished based on the applied jellifying agents and the API's. All samples were considered non-similar based on the pairwise comparison. The biocompatibility properties were determined by prolonged MTT assay on HeLa cells, and the polymer could be considered non-toxic. Based on the microbiological assay on E. coli metronidazole and chitosan containing samples had bactericidal effects while just metronidazole or just chitosan containing samples bacteriostatic effect. None of these samples showed a fungistatic or fungicide effect against C. albicans. Based on our results, we successfully manufactured 3D printed vaginal rings filled with jellified metronidazole.

Anti-counterfeiting protection, personalized medicines - Development of 2D identification methods using laser technology.

Counterfeiting of the products for healing is as old as trading, and it is difficult to quantify the magnitude of the problem. It is known that substandard and/or falsified (SF) medicines are a growing global threat to health, and they cause serious social and economic damage. The EU has a strong legal framework for medicines, it is mandatory to meet the requirements of Directive 2011/62/EU. Serialisation prevents SF medicinal products from entering the legal distribution chain. The present study is an extension of the original idea and aims to develop a laser technology-based method to mark an individual traceable code on the surface of the tablet, which technology can also be used for marking personalized medicines. The method is based on the ablation of the upper layer of a double-layer, differently coloured coating. The 2D code should be formed without harming the functional layer, and anyone with a smartphone integrated with a camera should be able to authenticate these drugs with a suitable application. The present findings confirmed that KrF excimer laser and Ti:sapphire femtosecond laser are efficient and reliable for marking. These should be promising candidates for pharmaceutical companies that would like to have additional protection against drug counterfeiters.

Formulation and Optimization of Sodium Alginate Polymer Film as a Buccal Mucoadhesive Drug Delivery System Containing Cetirizine Dihydrochloride.

Currently, pharmaceutical companies are working on innovative methods, processes and products. Oral mucoadhesive systems, such as tablets, gels, and polymer films, are among these possible products. Oral mucoadhesive systems possess many advantages, including the possibility to be applied in swallowing problems. The present study focused on formulating buccal mucoadhesive polymer films and investigating the physical and physical-chemical properties of films. Sodium alginate (SA) and hydroxypropyl methylcellulose (HPMC) were used as film-forming agents, glycerol (GLY) was added as a plasticizer, and cetirizine dihydrochloride (CTZ) was used as an active pharmaceutical ingredient (API). The polymer films were prepared at room temperature with the solvent casting method by mixed two-level and three-level factorial designs. The thickness, tensile strength (hardness), mucoadhesivity, surface free energy (SFE), FTIR, and Raman spectra, as well as the dissolution of the prepared films, were investigated. The investigations showed that GLY can reduce the mucoadhesivity of films, and CTZ can increase the tensile strength of films. The distribution of CTZ proved to be homogeneous in the films. The API could dissolve completely from all the films. We can conclude that polymer films with 1% and 3% GLY concentrations are appropriate to be formulated for application on the buccal mucosa as a drug delivery system.

PLGA based film forming systems for superficial fungal infections treatment.

As proven in clinical trials, superficial fungal infections can be effectively treated by single topical application of terbinafine hydrochloride (Ter-HCl) in a film forming system (FFS). Poly(lactic-co-glycolic acid) (PLGA) derivatives, originally synthesized with intention to get carriers with optimized properties for drug delivery, and multifunctional plasticizers - ethyl pyruvate, methyl salicylate, or triacetin - were used for formulation of Ter-HCl loaded FFSs. After spraying, a biodegradable, transparent, adhesive, and occlusive thin layer is formed on the skin, representing drug depot. In situ formed films were characterized by thermal, structural, viscoelastic, and antifungal properties as well as drug release and skin penetration. DSC and SEM showed fully amorphous films with Ter-HCl dissolved in PLGA in high concentration (up to 15%). FFSs are viscoelastic fluids with viscosity which can be easily adjusted by the type of plasticizer used and its concentration. The formulations showed excellent bioadhesion properties, thus ensuring persistence on the skin. In situ film based on branched PLGA/A plasticized with 10% of ethyl pyruvate allowed prolonged release of Ter-HCl by linear kinetics for the first 6 days with a total time of almost 14 days. During ex vivo human skin penetration experiment, Ter-HCl was found to be located only in its target layer, the epidermis. According to our results, plasticized branched PLGA derivatives loaded by Ter-HCl are suitable for the development of FFSs for superficial fungal infections treatment.

In Vitro Tests of FDM 3D-Printed Diclofenac Sodium-Containing Implants.

One of the most promising emerging innovations in personalized medication is based on 3D printing technology. For use as authorized medications, 3D-printed products require different in vitro tests, including dissolution and biocompatibility investigations. Our objective was to manufacture implantable drug delivery systems using fused deposition modeling, and in vitro tests were performed for the assessment of these products. Polylactic acid, antibacterial polylactic acid, polyethylene terephthalate glycol, and poly(methyl methacrylate) filaments were selected, and samples with 16, 19, or 22 mm diameters and 0%, 5%, 10%, or 15% infill percentages were produced. The dissolution test was performed by a USP dissolution apparatus 1. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide dye (MTT)-based prolonged cytotoxicity test was performed on Caco-2 cells to certify the cytocompatibility properties. The implantable drug delivery systems were characterized by thermogravimetric and heatflow assay, contact angle measurement, scanning electron microscopy, microcomputed tomography, and Raman spectroscopy. Based on our results, it can be stated that the samples are considered nontoxic. The dissolution profiles are influenced by the material properties of the polymers, the diameter, and the infill percentage. Our results confirm the potential of fused deposition modeling (FDM) 3D printing for the manufacturing of different implantable drug delivery systems in personalized medicine and may be applied during surgical interventions.

Effects of Sucrose Palmitate on the Physico-Chemical and Mucoadhesive Properties of Buccal Films.

In our current research, sucrose palmitate (SP) was applied as a possible permeation enhancer for buccal use. This route of administration is a novelty as there is no literature on the use of SP in buccal mucoadhesive films. Films containing SP were prepared at different temperatures, with different concentrations of SP and different lengths of hydroxypropyl methylcellulose (HPMC) chains. The mechanical, structural, and in vitro mucoadhesive properties of films containing SP were investigated. Tensile strength and mucoadhesive force were measured with a device and software developed in our Institute. Positron annihilation lifetime spectroscopy (PALS) and X-ray powder diffractometry (XRPD) were applied for the structure analysis of the films. Mucoadhesive work was calculated in two ways: from the measured contact angle and compared with direct mucoadhesive work, which measured mucoadhesive force, which is direct mucoadhesion work. These results correlate linearly with a correlation coefficient of 0.98. It is also novel because it is a new method for the determination of mucoadhesive work.

Design and characterization of chitosan/citrate films as carrier for oral macromolecule delivery.

The oral delivery of biopharmaceuticals requires the including of absorption enhancer, protease inhibitor and a suitable carrier system. The aim of the present work was to formulate and characterize chitosan solutions/films incorporating citric acid (CA) as potential excipient in comparison to the well-known acetic acid (AA)-based films as a reference. Films were made by the solvent casting method with/without glycerol (G), propylene glycol (PG) and polyethylene glycol (PEG-400) as plasticizers. The minimum film forming temperature (MFFT) of the prepared solutions, film thickness, hardness/deformation, mucoadhesivity, moisture content, FT-IR spectra and surface free energy (SFE) were investigated. Chitosan has been reported as a safe and effective paracellular absorption enhancer for hydrophilic macromolecules, therefore there would be more rationale for incorporating CA as a solubility enhancer, a permeation enhancer and an enzyme inhibitor. CA shows good cross-linking, an ideal plasticizing property and increases both tensile strength and mucoadhesivity, thus its incorporation simplifies the formulation while improving effectiveness. We concluded that CA (3.5, 4 and 5 w/v %)-based chitosan solution could be used as a novel coating/subcoating polymer for oral macromolecule delivery, or as oral mucoadhesive films.

Review of recently used techniques and materials to improve the efficiency of orally administered proteins/peptides.

OBJECTIVES: The main objective of present review is to explore and evaluate the effectiveness of recently developed methods to improve the bioavailability of orally administered biopharmaceutical drugs. METHODS: A systematic search of sciencedirect, tandfonline and Google Scholar databases based on various sets of keywords was performed. All results were evaluated based on their abstracts, and irrelevant studies were neglected during further evaluation. RESULTS: At present, biopharmaceuticals are used as injectable therapies as they are not absorbed adequately from the different routes of drug administration, particularly the oral one. Their insufficient absorption is attributed to their high molecular weight, degradation by proteolytic enzymes, high hydrophilicity and rigidity of the absorptive tissues. From industrial aspect incorporation of enzyme inhibitors (EIs) and permeation enhancers (PEs) and mucoadhesive polymers into conventional dosage forms may be the easiest way of formulation of orally administered macromolecular drugs, but the effectiveness of protection and absorption enhancement here is the most questionable. Conjugation may be problematic from regulatory aspect. Encapsulation into lipid-based vesicles sufficiently protects the incorporated macromolecule and improves intestinal uptake but have considerable stability issues. In contrast, polymeric nanocarriers may provide good stability but provides lower internalization efficacy in comparison with the lipid-based carriers. CONCLUSION: It can be concluded that the combination of the advantages of mucoadhesive polymeric and lid-based carriers in hybrid lipid/polymer nanoparticles may result in improved absorption and might represent a potential means for the oral administration of therapeutic proteins in the near future. Graphical abstract Delivery systems for oral protein daministration.

Optimization of the Production Process and Product Quality of Titanate Nanotube-Drug Composites.

Recently, there has been an increasing interest in the application of nanotubular structures for drug delivery. There are several promising results with carbon nanotubes; however, in light of some toxicity issues, the search for alternative materials has come into focus. The objective of the present study was to investigate the influence of the applied solvent on the composite formation of titanate nanotubes (TNTs) with various drugs in order to improve their pharmacokinetics, such as solubility, stability, and bioavailability. Composites were formed by the dissolution of atenolol (ATN) and hydrochlorothiazide (HCT) in ethanol, methanol, 0.01 M hydrochloric acid or in ethanol, 1M sodium hydroxide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), respectively, and then they were mixed with a suspension of TNTs under sonication for 30 min and vacuum-dried for 24 h. The structural properties of composites were characterized by SEM, TEM, FT-IR, differential scanning calorimetry (DSC), thermogravimetric (TG) analysis, and optical contact angle (OCA) measurements. Drug release was determined from the fast disintegrating tablets using a dissolution tester coupled with a UV-Vis spectrometer. The results revealed that not only the good solubility of the drug in the applied solvent, but also the high volatility of the solvent, is necessary for an optimal composite-formation process.

Comparison of conventionally and naturally coloured coatings marked by laser technology for unique 2D coding of pharmaceuticals.

Substandard and/or falsified medicines are a growing global threat for health and they cause serious social and economic damage. In low- and middle-income countries the failure rate of these medical products is approximately 10.5%. 50% of medicines purchased over the Internet may be fake. According to Directive 2011/62/EU as regards the prevention of falsified medicines from entering into the legal supply chain, a unique identification should be put on each box of drugs in the EU from 9th February 2019. The current project is focusing on the development of a laser technology to mark an individual traceable code on the surface of the tablet. Usually, coatings contain titanium dioxide for sufficient coverage, which makes precision laser coding more difficult. New naturally coloured films do not include those excipients. In this research, we would like to compare the physical-chemical properties of conventionally and naturally coloured coatings after the laser marking procedure by using two types of lasers. This unique identification technology can be used for marking personalized medicine with the doses tailored for each patient, too. To sum up, the present findings may contribute to efficient and reliable laser marking solutions in the unique identification procedure. Based on our measurement results, it can be stated that excimer UV lasers are promising candidates as marking instruments for the polymer film in both conventionally and naturally coloured coatings.