Lipid Nanoparticles: An Effective Tool to Improve the Bioavailability of Nutraceuticals.

Nano-range bioactive colloidal carrier systems are envisaged to overcome the challenges associated with treatments of numerous diseases. Lipid nanoparticles (LNPs), one of the extensively investigated drug delivery systems, not only improve pharmacokinetic parameters, transportation, and chemical stability of encapsulated compounds but also provide efficient targeting and reduce the risk of toxicity. Over the last decades, nature-derived polyphenols, vitamins, antioxidants, dietary supplements, and herbs have received more attention due to their remarkable biological and pharmacological health and medical benefits. However, their poor aqueous solubility, compromised stability, insufficient absorption, and accelerated elimination impede research in the nutraceutical sector. Owing to the possibilities offered by various LNPs, their ability to accommodate both hydrophilic and hydrophobic molecules and the availability of various preparation methods suitable for sensitive molecules, loading natural fragile molecules into LNPs offers a promising solution. The primary objective of this work is to explore the synergy between nature and nanotechnology, encompassing a wide range of research aimed at encapsulating natural therapeutic molecules within LNPs.

Novel aspects of Raman spectroscopy in skin research.

The analytical technology of Raman spectroscopy has an almost 100-year history. During this period, many modifications and developments happened in the method like discovery of laser, improvements in optical elements and sensitivity of spectrometer and also more advanced light detection systems. Many types of the innovative techniques appeared (e.g. Transmittance Raman spectroscopy, Coherent Raman Scattering microscopy, Surface-Enhanced Raman scattering and Confocal Raman spectroscopy/microscopy). This review article gives a short description about these different Raman techniques and their possible applications. Then, a short statistical part is coming about the appearance of Raman spectroscopy in the scientific literature from the beginnings to these days. The third part of the paper shows the main application options of the technique (especially confocal Raman spectroscopy) in skin research, including skin composition analysis, drug penetration monitoring and analysis, diagnostic utilizations in dermatology and cosmeto-scientific applications. At the end, the possible role of artificial intelligence in Raman data analysis and the regulatory aspect of these techniques in dermatology are briefly summarized. For the future of Raman Spectroscopy, increasing clinical relevance and in vivo applications can be predicted with spreading of non-destructive methods and appearance with the most advanced instruments with rapid analysis time.

Rheological effects of hypertonic saline and sodium bicarbonate solutions on cystic fibrosis sputum in vitro.

BACKGROUND: Cystic fibrosis (CF) is a life-threatening multiorgan genetic disease, particularly affecting the lungs, where recurrent infections are the main cause of reduced life expectancy. In CF, mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein impair transepithelial electrolyte and water transport, resulting in airway dehydration, and a thickening of the mucus associated with abnormal viscoelastic properties. Our aim was to develop a rheological method to assess the effects of hypertonic saline (NaCl) and NaHCO3 on CF sputum viscoelasticity in vitro, and to identify the critical steps in sample preparation and in the rheological measurements. METHODS: Sputum samples were mixed with hypertonic salt solutions in vitro in a ratio of either 10:4 or 10:1. Distilled water was applied as a reference treatment. The rheological properties of sputum from CF patients, and the effects of these in vitro treatments, were studied with a rheometer at constant frequency and strain, followed by frequency sweep tests, where storage modulus (G'), loss modulus (G″) and loss factor were determined. RESULTS: We identified three distinct categories of sputum: (i) highly elastic (G' > 100,000 Pa), (ii) elastic (100,000 Pa > G' > 1000 Pa), and (iii) viscoelastic (G' < 1000). At the higher additive ratio (10:4), all of the added solutions were found to significantly reduce the gel strength of the sputum, but the most pronounced changes were observed with NaHCO3 (p < 0.001). Samples with high elasticity exhibited the greatest changes while, for less elastic samples, a weakening of the gel structure was observed when they were treated with water or NaHCO3, but not with NaCl. For the viscoelastic samples, the additives did not cause significant changes in the parameters. When the lower additive ratio (10:1) was used, the mean values of the rheological parameters usually decreased, but the changes were not statistically significant. CONCLUSION: Based on the rheological properties of the initial sputum samples, we can predict with some confidence the treatment efficacy of each of the alternative additives. The marked differences between the three categories suggest that it is advisable to evaluate each sample individually using a rheological approach such as that described here.

In vitro testing of thiolated poly(aspartic acid) from ophthalmic formulation aspects.

Ocular drug delivery formulations must meet anatomical, biopharmaceutical, patient-driven and regulatory requirements. Mucoadhesive polymers can serve as a better alternative to currently available ophthalmic formulations by providing improved bioavailability. If all requirements are addressed, a polymeric formulation resembling the tear film of the eye might be the best solution. The optimum formulation must not have high osmotic activity, should provide appropriate surface tension, pH and refractive index, must be non-toxic and should be transparent and mucoadhesive. We would like to highlight the importance of in vitro polymer testing from a pharmaceutical aspect. We, therefore, carried out physical-chemical investigations to verify the suitability of certain systems for ophthalmic formulations. In this work, in situ gelling, mucoadhesive thiolated poly(aspartic acid)s were tested from ophthalmic formulation aspects. The results of preformulation measurements indicate that these polymers can be used as potential carriers in ophthalmic drug delivery.

The Effect of Electroporation of a Lyotroic Liquid Crystal Genistein-Based Formulation in the Recovery of Murine Melanoma Lesions.

A lamellar lyotropic liquid crystal genistein-based formulation (LLC-Gen) was prepared in order to increase the aqueous solubility of the lipophilic phytocompound genistein. The formulation was applied locally, in a murine model of melanoma, with or without electroporation. The results demonstrated that, when the formulation was applied by electroporation, the tumors appeared later. During the 21 days of the experiment, the LLC-Gen formulation decreased the tumor volume, the amount of melanin and the degree of erythema, but when electroporation was applied, all these parameters indicated a better prognosis even (lower tumor volume, amount of melanin and degree of erythema). Although hematoxylin-eosin (HE) staining confirmed the above events, application of the LLC-Gen formulation by electroporation did not lead to a significant effect in terms of the serum concentrations of the protein S100B and serum neuron specific enolase (NSE), or the tissue expression of the platelet-derived growth factor receptor ß (PDGFRß) antibody.

[Use of a novel polymer, the in-situ gelling mucoadhesive thiolated poly(aspartic acid) in ophthalmic drug delivery]. / Egy új típusú polimer, az in situ gélesedo tiolált poliaszparaginsav alkalmazása szemészeti gyógyszerhordozóként.

The bioavailability of drugs used on mucosal surfaces can be increased by the use of mucoadhesive polymers. A new type of mucoadhesive polymers is the group of thiolated polymers with thiol group containing side chains. These polymers are able to form covalent bonds (disulphide linkages) with the mucin glycoproteins. For the formulation of an ocular drug delivery system (DDS) thiolated poly(aspartic acid) polymer (ThioPASP) was used. Our aim was to determine their biocompatibility, mucoadhesion and drug release property. According to the results it can be established that the thiolated poly(aspartic acid) polymers can be a potential vehicle of an ocular drug delivery system due to their biocompatibility, good mucoadhesive property and drug release profile. Thanks to their properties controlled drug delivery can be achieved and bioavailability of the ophthalmic formulation can be increased, while the usage frequency can be decreased.

An Analytical Target Profile for the Development of an In Vitro Release Test Method and Apparatus Selection in the Case of Semisolid Topical Formulations.

This study focuses on how to define an Analytical Target Profile (ATP) which is intended for use in practice and on facilitating the selection of in vitro release test (IVRT) technology for diclofenac sodium topical hydrogel and cream. The implementation involves incorporating the new draft guidelines of the International Council for Harmonisation (ICH Q14) and USP (United States Pharmacopeia) Chapter 1220. Four IVRT apparatuses were compared (USP Apparatus II with immersion cell, USP Apparatus IV with semisolid adapter, static vertical diffusion cell, and a new, in-house-developed flow-through diffusion cell) with the help of the ATP. Performance characteristics such as accuracy, precision, cumulative amount released at the end of the IVRT experiment, and robustness were investigated. We found that the best apparatus for developing IVRT quality control (QC) tests in both cases was USP II with an immersion cell. All four different IVRT apparatuses were compared with each other and with the data found in the literature.

Foams Set a New Pace for the Release of Diclofenac Sodium.

Medicated foams have emerged as promising alternatives to traditional carrier systems in pharmaceutical research. Their rapid and convenient application allows for effective treatment of extensive or hirsute areas, as well as sensitive or inflamed skin surfaces. Foams possess excellent spreading capabilities on the skin, ensuring immediate drug absorption without the need for intense rubbing. Our research focuses on the comparison of physicochemical and biopharmaceutical properties of three drug delivery systems: foam, the foam bulk liquid, and a conventional hydrogel. During the development of the composition, widely used diclofenac sodium was employed. The safety of the formulae was confirmed through an in vitro cytotoxicity assay. Subsequently, the closed Franz diffusion cell was used to determine drug release and permeation in vitro. Ex vivo Raman spectroscopy was employed to investigate the presence of diclofenac sodium in various skin layers. The obtained results of the foam were compared to the bulk liquid and to a conventional hydrogel. In terms of drug release, the foam showed a rapid release, with 80% of diclofenac released within 30 min. In summary, the investigated foam holds promising potential as an alternative to traditional dermal carrier systems, offering faster drug release and permeation.

Formulation and investigation of hydrogels containing an increased level of diclofenac sodium using risk assessment tools.

Transdermal delivery of active ingredients is a challenge for pharmaceutical technology due to their inadequate penetration properties and the barrier function of the skin. The necessity of painless, effective, topical therapy for the aging population is growing, and a variety of diclofenac sodium-containing semi-solid preparations are available to alleviate the symptoms of these ailments. Our purpose was to formulate a novel composition with higher drug content to enhance drug release and permeation, thereby providing more effective therapy. Another goal was to maintain the concentration of the organic solvent mixture below 30%, to protect the skin barrier. Firstly, literature and market research were conducted, based on which the appropriate excipients for the target formulation were selected. Solubility tests were conducted with binary and ternary mixtures. As a result, the optimal ternary mixture was chosen. Hydrogels containing 1, 5, and 7% of diclofenac sodium were prepared and the stability of the formulations were studied by microscopic measurements and cytotoxicity test were carried out of the components also. The release and permeation of diclofenac sodium were investigated in different concentrations. It can be concluded that we have succeeded in preparing a topically applicable stable diclofenac sodium hydrogel with higher concentration, drug release, and improved skin permeation than the formulations available on the market.

Improvement of lidocaine skin permeation by using passive and active enhancer methods.

Lidocaine is generally recognized and preferred for local anaesthesia, but in addition, studies have described additional benefits of lidocaine in cancer therapy, inflammation reduction, and wound healing. These properties contribute to its increasing importance in dermatological applications, and not only in pain relief but also in other potential therapeutic outcomes. Therefore, the purpose of our study was to enhance lidocaine delivery through the skin. A stable nanostructured lipid carrier (NLC), as a passive permeation enhancer, was developed using a 23 full factorial design. The nanosystems were characterized by crystallinity behaviour, particle size, zeta potential, encapsulation efficiency measurements, and one of them was selected for further investigation. Then, NLC gel was formulated for dermal application and compared to a traditional dermal ointment in terms of physicochemical (rheological behaviour) and biopharmaceutical (qualitative Franz diffusion and quantitative Raman investigations) properties. The study also examined the use of 3D printed solid microneedles as active permeation enhancers for these systems, offering a minimally invasive approach to enhance transdermal drug delivery. By actively facilitating drug permeation through the skin, microneedles can complement the passive transport achieved by NLCs, thereby providing an innovative and synergistic approach to improving lidocaine delivery.

Factorial design of in situ gelling two-compartment systems containing chlorhexidine for the treatment of periodontitis.

Periodontitis is one of the most widespread bacterial infectious oral diseases that affects a significant percentage of the population worldwide. Different bacterial strains are responsible for the chronic inflammation and subgingival plaque that could be effectively treated with prolonged exposure to therapeutic levels of antibiotics and antiseptics in the periodontal pockets. Medicated in situ gels of chlorhexidine (CHX), for extended drug release and long-lasting antiseptic effect in the targeted cavities, were prepared in a two-compartment system. One compartment was loaded with sodium alginate solution while other was filled with CHX and calcium solution. The mixing of the solutions during the application resulted in gelation. Two 33 full factorial designs were applied in this study in order to optimize the gel formulation. Initially, the effects of concentration of gelling agent, crosslinker, and pH of the system on the dependent variables such as gel formation and structure characteristics were investigated. Then, the concentration of the crosslinker was optimized. Afterwards, the effect of gelling agent, loading of the drug, and pH of the gel system were correlated with the gel characteristics through another factorial design. Optimized formulations were tested for mucoadhesion, in vitro drug release, and microbiological investigation. Based on the results of the factorial design, mucoadhesiveness, antimicrobial investigation, and drug release, a 4 % alginate composition can be considered optimal. Overall, the optimized in situ periodontal gel was found to be effective with prolonged retention time and desirable outcomes.

Combined Nanofibrous Face Mask: Co-Formulation of Lipases and Antibiotic Agent by Electrospinning Technique.

The application of enzyme-based therapies has received significant attention in modern drug development. Lipases are one of the most versatile enzymes that can be used as therapeutic agents in basic skin care and medical treatment related to excessive sebum production, acne, and inflammation. The traditional formulations available for skin treatment, such as creams, ointments or gels, are widely applied; however, their use is not always accompanied by good drug penetration properties, stability, or patient adherence. Nanoformulated drugs offer the possibility of combining enzymatic and small molecule formulations, making them a new and exciting alternative in this field. In this study polymeric nanofibrous matrices made of polyvinylpyrrolidone and polylactic acid were developed, entrapping lipases from Candida rugosa and Rizomucor miehei and antibiotic compound nadifloxacin. The effect of the type of polymers and lipases were investigated, and the nanofiber formation process was optimized to provide a promising alternative in topical treatment. Our experiments have shown that entrapment by electrospinning induced two orders of magnitude increase in the specific enzyme activity of lipases. Permeability investigations indicated that all lipase-loaded nanofibrous masks were capable of delivering nadifloxacin to the human epidermis, confirming the viability of electrospinning as a formulation method for topical skin medications.

A novel murine model for the in vivo study of transdermal drug penetration.

Enhancement of the transdermal penetration of different active agents is an important research goal. Our aim was to establish a novel in vivo experimental model which provides a possibility for exact measurement of the quantity of penetrated drug. The experiments were performed on SKH-1 hairless mice. A skin fold in the dorsal region was fixed with two fenestrated titanium plates. A circular wound was made on one side of the skin fold. A metal cylinder with phosphate buffer was fixed into the window of the titanium plate. The concentration of penetrated drug was measured in the buffer. The skin fold was morphologically intact and had a healthy microcirculation. The drug appeared in the acceptor buffer after 30 min, and its concentration exhibited a continuous increase. The presence of ibuprofen was also detected in the plasma. In conclusion, this model allows an exact in vivo study of drug penetration and absorption.

Ibuprofen penetration enhance by sucrose ester examined by ATR-FTIR in vivo.

The aim of this work was to investigate the skin penetration enhancer effect of a sucrose ester (SE) in an Ibuprofen (IBU) containing hydrogel and to examine its influence on the special lipid bilayer of the stratum corneum (SC). ATR-FTIR spectroscopic measurements were performed combined with tape stripping method on hairless mice in vivo. A SE containing gel was compared to another gel without SE. It was found that the preparations caused only minimal modifications in the lipid and the protein structure, promoting the skin hydration and therefore also the penetration of IBU. Although the degree of moisturization and penetration were more intense in the case of the SE containing gel treatment, it did not cause greater alterations in the SC structure than the gel without SE. It has been proven that SE acts as an effective and non-irritating hydration and penetration enhancer for IBU through skin.

[Modelling of pecutaneous drug permeation and investigation of penetration enhancer effect]. / A borön keresztüli hatóanyag permeáció modellezése és penetrációfokozók hatásának vizsgálata.

Present study provides a short review concerning the applicable membranes for modelling the percutaneous drug permeation and about their importance. The theoretical introduction summarizes the transdermal drug permeation routes and enhancement strategies. Two penetration enhancers are presented, the Transcutol and a sucrose ester, the Sucrose laurate which can offer an interesting possibility. Various recently applied and tested membranes (synthetic membrane, human, animal and artificial skin) are shown, which can be used for modelling dermal drug permeation. Furthermore two investigation methods are demonstrated for examining the drug diffusion, penetration and permeation, the vertical Franz diffusion cell and the ATR-FTIR spectroscopy, which can offer possibility for studying the skin at molecular level, too. Our previous in vitro, ex vivo and in vivo experimental results support, that choosing the appropriate model membrane is of primary importance. Examining the drug permeation through the skin is indispensable to get information about the interactions between the drug, the penetration enhancers and the skin as well, and to study also the drug accumulation in the skin.

Application of Xanthan Gum and Hyaluronic Acid as Dermal Foam Stabilizers.

Foams are increasingly popular in the field of dermatology due to their many advantages such as easy spreading, good skin sensation, and applicability in special skin conditions. One of the critical points of foam formulation is the choice of the appropriate stabilizing ingredients. One of the stability-increasing strategies is retarding the liquid drainage of liquid films from the foam structure. Therefore, our aim was the application of different hydrogel-forming polymers in order to retain the stabilizing liquid film. Dexpanthenol and niacinamide-containing foams were formulated, where xanthan gum and hyaluronic acid were used as foam-stabilizing polymers. Amplitude (LVE range) and frequency sweep (G', G", tanδ, and frequency dependency) were applied as structure- and stability-indicating rheological parameters. The rheological data were compared with the results of the cylinder method, microscopical images, and the spreadability measurements. The application of the gel-forming polymers increased the stability of the dermal foams (increased LVE range, G' values, and decreased frequency dependency). These results were in correlation with the results of the cylinder and spreadability tests. It was concluded that in terms of both foam formation and stability, the combination of xanthan gum and dexpanthenol can be ideal.

The effects of glycols on molecular mobility, structure, and permeability in stratum corneum.

The skin provides an attractive alternative to the conventional drug administration routes. Still, it comes with challenges as the upper layer of the skin, the stratum corneum (SC), provides an efficient barrier against permeation of most compounds. One way to overcome the skin barrier is to apply chemical permeation enhancers, which can modify the SC structure. In this paper, we investigated the molecular effect of three different types of glycols in SC: dipropylene glycol (diPG), propylene glycol (PG), and butylene glycol (BG). The aim is to understand how these molecules influence the molecular mobility and structure of the SC components, and to relate the molecular effects to the efficiency of these molecules as permeation enhancers. We used complementary experimental techniques, including natural abundance 13C NMR spectroscopy and wide-angle X-ray diffraction to characterize the molecular consequences of these compounds at different doses in SC at 97% RH humidity and 32 °C. In addition, we study the permeation enhancing effects of the same glycols in comparable conditions using Raman spectroscopy. Based on the results from NMR, we conclude that all three glycols cause increased mobility in SC lipids, and that the addition of glycols has an effect on the keratin filaments in similar manner as Natural Moisturizing Factor (NMF). The highest mobility of both lipids and amino acids can be reached with BG, which is followed by PG. It is also shown that one reaches an apparent saturation level for all three chemicals in SC, after which increased addition of the compound does not lead to further increase in the mobility of SC lipids or protein components. The examination with Raman mapping show that BG and PG give a significant permeation enhancement as compared to SC without any added glycol at corresponding conditions. Finally, we observe a non-monotonic response in permeation enhancement with respect to the concentration of glycols, where the highest concentration does not give the highest permeation. This is explained by the dehydration effects at highest glycol concentrations. In summary, we find a good correlation between the molecular effects of glycols on the SC lipid and protein mobility, and macroscopic permeation enhances of the same molecules.

Investigation of the effect of polymers on dermal foam properties using the QbD approach.

Dermal foams are promising drug delivery systems due to their many advantages and ease of application. Foams are also considered a novelty in the field of dermatology. In particular, they are beneficial for the treatment of skin conditions where patients have highly inflamed, swollen, infected and sensitive skin, as the application of the foam to the skin surface to be treated minimizes the need for skin contact. In order to formulate foams, it is necessary to know which material and process parameters influence the quality characteristics of foams and which methods can be used to study foams; this part of the research is assisted by the QbD approach. By using the QbD concept, it contributed during the development process to ensure quality-based development. With initial risk assessment, the critical material attributes (CMAs) and the critical process parameters (CPPs) were identified to ensure the required critical quality attributes (CQAs). During the initial risk assessment, five high-risk CQAs, namely foam volume stability, foam expansion, cross point, the initial values of the number and size of bubbles, and three medium-risk CQAs, namely spreadability, relative foam density and viscosity of the liquid system were identified and investigated. In this research, different types of polymers (xanthan gum, hydroxyethylcellulose, different types of hyaluronic acids) were used to improve the properties of foam formulations. The formulations containing xanthan gum and high molecular weight hyaluronic acid had good foam properties and will be appropriate delivery systems for an active pharmaceutical ingredient. Overall, the polymer content had a great effect on the properties of the foams. Different polymers affect the properties of foams in different ways. When used in combination, the methods reinforce each other and help to select a formula for dermal application.

Analytical Quality by Design (AQbD) Approach to the Development of In Vitro Release Test for Topical Hydrogel.

The aim of our study was to adapt the analytical quality by design (AQbD) approach to design an effective in vitro release test method using USP apparatus IV with a semi-solid adapter (SSA) for diclofenac sodium hydrogel. The analytical target profile (ATP) of the in vitro release test and ultra-high-performance liquid chromatography were defined; the critical method attributes (CMAs) (min. 70% of the drug should be released during the test, six time points should be obtained in the linear portion of the drug release profile, and the relative standard deviation of the released drug should not be over 10%) were selected. An initial risk assessment was carried out, in which the CMAs (ionic strength, the pH of the media, membrane type, the rate of flow, the volume of the SSA (sample amount), the individual flow rate of cells, drug concentration %, and the composition of the product) were identified. With the results, it was possible to determine the high-risk parameters of the in vitro drug release studies performed with the USP apparatus IV with SSA, which were the pH of the medium and the sample weight of the product. Focusing on these parameters, we developed a test protocol for our hydrogel system.

Development of Capsaicin-Containing Analgesic Silicone-Based Transdermal Patches.

Transdermal therapeutic systems (TTSs) enable convenient dosing in drug therapy. Modified silicone-polymer-based patches are well-controlled and cost-effective matrix diffusion systems. In the present study, we investigated the substance release properties, skin penetration, and analgesic effect of this type of TTS loaded with low-dose capsaicin. Release properties were measured in Franz diffusion cell and continuous flow-through cell approaches. Capsaicin was detected with HPLC-UV and UV spectrophotometry. Raman spectroscopy was conducted on human skin samples exposed to the TTS. A surgical incision or carrageenan injection was performed on one hind paw of male Wistar rats. TTSs were applied to the epilated dorsal skin. Patches were kept on the animals for 6 h. The thermal hyperalgesia and mechanical pain threshold of the hind paws were detected. Patches exhibited controlled, zero-order kinetic capsaicin release. According to the Raman mapping, capsaicin penetrated into the epidermis and dermis of human skin, where the target receptors are expressed. The thermal pain threshold drop of the operated rat paws was reversed by capsaicin treatment compared to that of animals treated with control patches. It was concluded that our modified silicone-polymer-based capsaicin-containing TTS is suitable for the relief of traumatic and inflammatory pain.