Preparation and characterization of spray-dried gelatin microspheres encapsulating ganciclovir

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.

Construction of Unsaturated Collagen Microsphere System Based on Hydrogen/Coordination Bond and Application

In this paper, unsaturated collagen microspheres (CMA-Cr/ST) were constructed from vinyl collagen (CMA, which is from leather solid waste) and chromium/synthetic tannins (Cr/ST) through hydrogen and coordination bonds and grafted on polyamide nonwoven fiber by thiol-ene click chemistry to improve the moisture absorption and permeability of nonwoven. The results showed that when the quality ratio of CMA to Cr/ST was 1:1, the magnetic stirring time was 20 min with 250 rpm at room temperature, the surface and particle size distribution of the obtained microspheres were smooth and relatively uniform, and the average particle size was 2-3 μm. When the concentrations of the microspheres and the initiators were 6 and 0.006 wt %, the irradiation time was 4 h and the grafting rate of CMA-Cr/ST on the surface of polyamide fibers would reach 31.3%. The moisture absorption and permeability of the obtained microsphere-modified polyamide nonwoven fiber (CMA-Cr/ST-S-PA) were increased. It was found that the collagen microspheres were firmly modified on the polyamide fibers by moisture and heat resistance, wash resistance, and solvent resistance studies.

The Impact of Gelatin on the Pharmaceutical Characteristics of Fucoidan Microspheres with Posaconazole

Fungal infections and invasive mycoses, despite the continuous medicine progress, are an important globally therapeutic problem. Multicompartment dosage formulations (e.g., microparticles) ensure a short drug diffusion way and high surface area of drug release, which as a consequence can provide improvement of therapeutic efficiency compared to the traditional drug dosage forms. As fucoidan is promising component with wide biological activity per se, the aim of this study was to prepare fucospheres (fucoidan microparticles) and fucoidan/gelatin microparticles with posaconazole using the one-step spray-drying technique. Pharmaceutical properties of designed fucospheres and the impact of the gelatin addition on their characteristics were evaluated. An important stage of this research was in vitro evaluation of antifungal activity of developed microparticles using different Candida species. It was observed that gelatin presence in microparticles significantly improved swelling capacity and mucoadhesiveness, and provided a sustained POS release. Furthermore, it was shown that gelatin addition enhanced antifungal activity of microparticles against tested Candida spp. strains. Microparticles formulation GF6, prepared by the spray drying of 20% fucoidan, 5% gelatin and 10% Posaconazole, were characterized by optimal mucoadhesive properties, high drug loading and the most sustained drug release (after 8 h 65.34 ± 4.10% and 33.81 ± 5.58% of posaconazole was dissolved in simulated vaginal fluid pH 4.2 or 0.1 M HCl pH 1.2, respectively).

Osteogenic Effect of a Biodegradable BMP-2 Hydrogel Injected into a Cannulated Mg Screw

Cannulated screws, containing an internal hole for inserting a guide pin, are commonly used in the management of bone fractures. Cannulated Mg screws can be biodegraded easily because their increased surface area including that of the inner hole rapidly reacts with body fluids. To delay biodegradation of cannulated Mg screws and improve bone regeneration, we developed a specific type of screw by injecting it with gelatin hydrogels [10 wt % gelatin_(gel) with 0.09 v/v % glutaraldehyde (cross-linker)] containing different concentrations (5, 10, or 25 μg/mL) of bone morphogenic proteins (BMPs). We analyzed the properties and biocompatibility of the screws with and without BMP-2 and found that the release rate of BMP-2 in the hydrogel changed proportionately with the degradation rate of the cross-linked hydrogel. Loading BMP-2 in the hydrogel resulted in sustained release of BMP-2 for 25 to 40 days or more. The degradation rate of BMP-2 hydrogels was inversely proportional to the concentration of BMP-2. The injection of the hydrogels in the cannulated screw delayed biodegradation inside of the screw by simulated body fluid. It also induced uniform corrosion and the precipitation of bioactive compounds onto the surface of the screw. In addition, osteoblast proliferation was very active near the BMP-2 hydrogels, depending on the BMP-2 concentration. The BMP-2 in the hydrogel improved cell differentiation. The cannulated screw injected with 10 μL/mL BMP-2 hydrogel prevented implant biodegradation and enhanced osteoconduction and osteointegration inside and outside the screw. In addition, the properties of BMP-2-loaded hydrogels can be changed by controlling the amount of the cross-linker and protein, which could be useful for tissue regeneration in other fields.

Therapeutic potential of phenylethanoid glycosides: A systematic review

Phenylethanoid glycosides (PhGs) are generally water-soluble phenolic compounds that occur in many medicinal plants. Until June 2020, more than 572 PhGs have been isolated and identified. PhGs possess antibacterial, anticancer, antidiabetic, anti-inflammatory, antiobesity, antioxidant, antiviral, and neuroprotective properties. Despite these promising benefits, PhGs have failed to fulfill their therapeutic applications due to their poor bioavailability. The attempts to understand their metabolic pathways to improve their bioavailability are investigated. In this review article, we will first summarize the number of PhGs compounds which is not accurate in the literature. The latest information on the biological activities, structure-activity relationships, mechanisms, and especially the clinical applications of PhGs will be reviewed. The bioavailability of PhGs will be summarized and factors leading to the low bioavailability will be analyzed. Recent advances in methods such as bioenhancers and nanotechnology to improve the bioavailability of PhGs are also summarized. The existing scientific gaps of PhGs in knowledge are also discussed, highlighting research directions in the future.

Controlling the Skin Barrier Quality through the Application of Polymeric Films Containing Microspheres with Encapsulated Plant Extract

Human skin has protective functions and it is a barrier that protects the interior of the body from harmful environmental factors and pathogen penetration. An important role of the skin is also to prevent the loss of water from the body and if the skin barrier is damaged, the amount of water emitted from the internal environment is increased. Therefore, it is crucial to recovery and maintenance of epidermal barrier integrity. The aim of the current work was to encapsulate Calendula officinalis flower extract in gelatin microspheres and then incorporation microspheres into thin polymeric films made from sodium alginate or mixture of sodium alginate and starch. Such materials may find applications in the cosmetic field for example in the preparation of masks for skin, according to the Calendula officinalis flower extract wide influence on skin condition. Thus, the release profile of this extract from the materials was tested under conditions corresponding to the skin (pH 5.4, 37 °C). The mechanical properties, surface free energy, and moisture content of obtained films were measured. To determine the barrier quality of the stratum corneum, transepidermal water loss (TEWL) and skin color measurements were performed. The loaded microspheres were successfully incorporated into polymeric films without affecting its useful properties. Although the values of Young’s modulus and the moisture content were decreased after film modification by microspheres addition, the skin parameters were much better after application of films with microspheres. The results confirmed that obtained materials can be potentially used in cosmetics to improve the skin barrier quality.

Comparison of pharmaceutical quality of eight generic ganciclovir injections in China and Cymevene

To assess the pharmaceutical quality of eight commercially available generic products of ganciclovir injection produced in China with original brand product (Cymevene, Roche, Switzerland). Tests were performed according to China Pharmacopoeia 2015 and Import Drug Registration Standard introduced by CFDA. Items including characteristics of the packing and reconstituted solution, pH, visible particles, content of active and related substances, sterility and bacterial endotoxin were all carried out based on the standard laboratory operating rules and requirements. Seven of all tested domestically produced generics of ganciclovir for injection failed to reach the in vitro quality requirements in comparison with the original brand product Cymevene. Three generics failed to meet the standards for pH of an aqueous solution. One out of eight generic products fell outside the specifications for API content. All generics showed impurities, whose levels were generally greater than observed in the brand product. One generic product was identified an endotoxin contamination. In addition, six generic products failed to reach the quality requirements of water content, which should be under 3%. Most tested ganciclovir products failed to meet the pharmaceutical quality standards for original brand product. Important items like pH, endotoxin contamination, content of API and impurities could cause clinical attention, as they directly affect the therapeutic efficacy and patient tolerance.

Recent strategies in spray drying for the enhanced bioavailability of poorly water-soluble drugs

Poorly water-soluble drugs are a significant and ongoing issue for the pharmaceutical industry. An overview of recent developments for the preparation of spray-dried delivery systems is presented. Examples include amorphous solid dispersions, spray dried dispersions, microparticles, nanoparticles, surfactant systems and self-emulsifying drug delivery systems. Several aspects of formulation are considered, such as pre-screening, choosing excipient(s), the effect of polymer structure on performance, formulation optimisation, ternary dispersions, fixed-dose combinations, solvent selection and component miscibility. Process optimisation techniques including nozzle selection are discussed. Comparisons are drawn with other preparation techniques such as hot melt extrusion, freeze drying, milling, electro spinning and film casting. Novel analytical and dissolution techniques for the characterization of amorphous solid dispersions are included. Progress in understanding of amorphous supersaturation or recrystallisation from solution gathered from mechanistic studies is discussed. Aspects of powder flow and compression are considered in a section on downstream processing. Overall, spray drying has a bright future due to its versatility, efficiency and the driving force of poorly soluble drugs.

Biomaterials and Culture Technologies for Regenerative Therapy of Liver Tissue

Regenerative approach has emerged to substitute the current extracorporeal technologies for the treatment of diseased and damaged liver tissue. This is based on the use of biomaterials that modulate the responses of hepatic cells through the unique matrix properties tuned to recapitulate regenerative functions. Cells in liver preserve their phenotype or differentiate through the interactions with extracellular matrix molecules. Therefore, the intrinsic properties of the engineered biomaterials, such as stiffness and surface topography, need to be tailored to induce appropriate cellular functions. The matrix physical stimuli can be combined with biochemical cues, such as immobilized functional groups or the delivered actions of signaling molecules. Furthermore, the external modulation of cells, through cocultures with nonparenchymal cells (e.g., endothelial cells) that can signal bioactive molecules, is another promising avenue to regenerate liver tissue. This review disseminates the recent approaches of regenerating liver tissue, with a focus on the development of biomaterials and the related culture technologies.

Preparation and Characterization of Genipin-Crosslinked Chitosan Microspheres for the Sustained Release of Salidroside

Chitosan microspheres (CsMs) that encapsulate salidroside (Sal) were prepared by the emulsion crosslinking method with naturally occurring genipin (Gp) and then examined for their in vitro release. Sal-loaded CsMs (Sal-CsMs) showed nearly spherical and smooth surfaces with internal voids. The particle size of Sal-CsMs ranged within 0.56–5.01 μm, and their encapsulation efficiency and loading capacity were beyond 77.58% and 23.29%, respectively. The stability of Sal improved after entrapment into the CsMs. The release rate of Sal from CsMs was initially rapid, followed by sustained release. The release behavior depended on the pH of the release medium. The main release mechanisms underlying the release procedure were anomalous behavior and Fickian diffusion. These results indicated that CsMs with a novel crosslinker of Gp was a potential carrier system for producing functional foods containing Sal.