Nanosuspensions: a promising drug delivery strategy

Needle-Free Jet Injectors and Nanosuspensions: Exploring the Potential of an Unexpected Pair

Needle-free liquid jet injectors are medical devices used to administer pharmaceutical solutions through the skin. Jet injectors generate a high-speed stream of liquid medication that can puncture the skin and deliver the drug to the underlying tissues. In this work, we investigated the feasibility of using liquid jet injectors to administer nanosuspensions, assessing the impact of the jet injection on their pharmaceutical and physicochemical properties. For this purpose, the model drug diclofenac was used to prepare a set of nanosuspensions, stabilized by poloxamer 188, and equilibrated at different pHs. The hydrodynamic diameter and morphology of the nanocrystals were analyzed before and after the jet injection across porcine skin in vitro, together with the solubility and release kinetics of diclofenac in a simulated subcutaneous environment. The efficacy of the jet injection (i.e., the amount of drug delivered across the skin) was evaluated for the nanosuspension and for a solution, which was used as a control. Finally, the nanosuspension was administered to rats by jet injector, and the plasma profile of diclofenac was evaluated and compared to the one obtained by jet injecting a solution with an equal concentration. The nanosuspension features were maintained after the jet injection in vitro, suggesting that no structural changes occur upon high-speed impact with the skin. Accordingly, in vivo studies demonstrated the feasibility of jet injecting a nanosuspension, reaching relevant plasma concentration of the drug. Overall, needle-free jet injectors proved to be a suitable alternative to conventional syringes for the administration of nanosuspensions.

In situ gelling nanosuspension as an advanced platform for fluticasone propionate nasal delivery

In this work we present the development of in situ gelling nanosuspension as advanced form for fluticasone propionate nasal delivery. Drug nanocrystals were prepared by wet milling technique. Incorporation of drug nanocrystals into polymeric in situ gelling system with pectin and sodium hyaluronate as constitutive polymers was fine-tuned attaining appropriate formulation surface tension, viscosity and gelling ability. Drug nanonisation improved the release profile and enhanced formulation mucoadhesive properties. QbD approach combining formulation and administration parameters resulted in optimised nasal deposition profile, with 51.8% of the dose deposited in the middle meatus, the critical region in the treatment of rhinosinusitis and nasal polyposis. Results obtained in biocompatibility and physico-chemical stability studies confirmed the leading formulation potential for safe and efficient nasal corticosteroid delivery.

Preparation, Characterization, and Evaluation of Breviscapine Nanosuspension and Its Freeze-Dried Powder

As a biopharmaceutics classification system (BCS) class IV drug, breviscapine (Bre) has low solubility in water, poor chemical stability, a short biological half-life and rapid removal from plasma. This paper prepared a Bre nanosuspension (Bre-NS) by an ultrasound-assisted anti-solvent precipitation method. Characterization of Bre-NS was studied using a Box–Behnken design concerning drug concentration in DMSO, an anti-solvent-to-solvent ratio, and sonication time. Under the optimized conditions of 170 mg/mL for the drug concentration, a 1:60 solvent-to-anti-solvent ratio, and a 9 min sonication time, the particle size of Bre-NS was 303.7 ± 7.3 nm, the polydispersity index was 0.178 ± 0.015, and the zeta potential was −31.10 ± 0.26 mV. Combined with the results from differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier transform-infrared spectroscopy (FT-IR), the findings indicated that the crystal form and chemical structure of Bre-NS did not change during the entire process. The optimized formulation displayed good stability, increased solubility, and better in vitro release. Therefore, the results of this study can be a reference for the delivery system design of insoluble active components and effective parts in traditional Chinese medicine.

Polymeric Nanocapsules Containing Fennel Essential Oil: Their Preparation, Physicochemical Characterization, Stability over Time and in Simulated Gastrointestinal Conditions

Plant essential oils, a source of biologically active compounds, represent a promising segment in the pharmaceutical market. However, their volatility, hydrophobicity, poor stability, and low toxicity limit direct use in pharmaceutical-related applications. Nanoencapsulation is a technique that allows overcoming these obstacles by improving bioaccessibility and bioavailability. Nanocapsules (NCs) based on biodegradable and biocompatible poly(ɛ-caprolactone) containing Foeniculum vulgare Mill. essential oil (FEO), known for its biological activities, were successfully prepared by interfacial deposition of the preformed polymer method. The composition of FEO (trans-anethole chemotype) was determined by gas chromatography analyses. The FEO presence inside the NCs was confirmed by nuclear magnetic resonance experiments. The FEO-NCs showed nanometer size (210 nm), low polydispersity index (0.10), negative zeta potential (-15 mV), non-Newtonian rheological behavior, and high efficiency of encapsulation (93%). Moreover, parameters such as FEO-NC particle size, bioactive compound retention, and FEO composition were monitored for 30 days at storage temperatures of 4 and 40 °C, confirming the robustness of the nanosystem. Finally, FEO-NCs were resistant to the simulated gastric digestion and showed an effective bioaccessibility of 29% in simulated intestinal digestion. Based on the results obtained, this FEO-NC nanosystem could find interesting applications in the nutraceutical and pharmaceutical sectors.

Effectiveness of nanoscale delivery systems on improving the bioavailability of lutein in rodent models: a systematic review

Lutein, a potent antioxidant and the main macular pigment that protects the macula from light-initiated oxidative damage, has low bioavailability. Various nanoscale delivery systems have been developed for improving its bioavailability. This systematic review aims to evaluate the effectiveness of nanoscale delivery systems on improving lutein bioavailability in rodent models. Using EBSCOhost and PubMed, a total of eleven peer-reviewed articles published from 2000 to 2020 were identified. Plasma lutein concentration, pharmacokinetic parameters, including maximum concentration (C_max), area under curve (AUC), and time to reach the maximum concentration (T_max), and lutein accumulation in organs were extracted to evaluate the bioavailability of lutein using nanoscale delivery methods as compared with unencapsulated or raw lutein. Various nanoscale delivery systems, including polymer nanoparticles, emulsions, and lutein nanoparticles, significantly improved the bioavailability of lutein, as evidenced by increased plasma lutein concentrations, C_max, or AUC. Additionally, five out of seven studies observed enhanced accumulation of lutein in the liver and the eyes. Polymer nanoparticles and emulsions improve the dispersibility and stability of lutein, thus lutein might be more accessible in the small intestine. Lutein nanoparticles shortened the T_max. Further studies are warranted to evaluate the effectiveness of nanoscale delivery systems on improving the functionalities of lutein.

Nanocrystals based mucosal delivery system: Research Advances

Nanocrystal technology is a new way to increase the solubility and bioavailability of poorly soluble drugs. As an intermediate preparation technology, nanocrystals are widely used in drug delivery for oral, venous, percutneous and inhalation administration, which exhibits a broad application prospect. By referring to the domestic anforeign literatures, this paper mainly reviews the preparation methods of nanocrystals for poorly soluble natural products and its application in the mucosal delivery for skin, eye, oral cavity and nasal cavity. This can provide the reference for the research and development of nanocrystal technology in natural product preparations.

Cyclodextrin Stabilized Freeze-Dried Silica/Chitosan Nanoparticles for Improved Terconazole Ocular Bioavailability

This research assesses the beneficial effects of loading terconazole, a poorly water-soluble antifungal drug in silica/chitosan nanoparticles (SCNs) for ocular delivery. Nanoparticles were fabricated by the simple mixing of tetraethyl ortho silicate (TEOS) and chitosan HCl as sources of silica and nitrogen, respectively, along with alcoholic drug solution in different concentrations. Freeze-dried nanoparticles were fabricated using cyclodextrins as cryoprotectants. SCNs were assessed for their particle size, PDI, yield, drug loading and in vitro release studies. A 2³.3¹ full factorial experimental design was constructed to optimize the prepared SCNs. DSC, XRD, FTIR, in addition to morphological scanning were performed on the optimized nanoparticles followed by an investigation of their pharmacokinetic parameters after topical ocular application in male Albino rabbits. The results reveal that increasing the water content in the preparations causes an increase in the yield and size of nanoparticles. On the other hand, increasing the TEOS content in the preparations, caused a decrease in the yield and size of nanoparticles. The optimized formulation possessed excellent mucoadhesive properties with potential safety concerning the investigated rabbit eye tissues. The higher C_max and AUC_0–24 values coupled with a longer t_max value compared to the drug suspension in the rabbits’ eyes indicated the potential of SCNs as promising ocular carriers for poorly water-soluble drugs, such as terconazole.

Development of Nanosuspension Formulations Compatible with Inkjet Printing for the Convenient and Precise Dispensing of Poorly Soluble Drugs

The pharmaceutical industry has been challenged by the increasing number of poorly soluble drug candidates, resulting in significant issues with obtaining sufficient absorption and bioavailability, risk of exposure variability, and difficulties in achieving a safe therapeutic index. Additionally, the rapid and precise dispensing of specific drug dosages is an important aspect that can enable personalized medicines for the patient. Herein, we report on the development of inkjet printing as a method for delivering precise quantities of poorly soluble drug molecules using commercially available equipment. Despite challenges due to low solubility making it difficult to prepare liquid solutions, stable suspensions of drug nanoparticles with the appropriate viscosity were successfully printed and dispensed onto a thin film suitable for delivery. The drug nanoparticles remained intact and could be reconstituted after printing, demonstrating that they remained stable and retained their advantageous particle size. This demonstrates that inkjet printing can be a practical and convenient approach for dispensing poorly soluble drug molecules when formulated as nanosuspensions.

Carrier-free nanodrugs with efficient drug delivery and release for cancer therapy: From intrinsic physicochemical properties to external modification

The considerable development of carrier-free nanodrugs has been achieved due to their high drug-loading capability, simple preparation method, and offering "all-in-one" functional platform features. However, the native defects of carrier-free nanodrugs limit their delivery and release behavior throughout the in vivo journey, which significantly compromise the therapeutic efficacy and hinder their further development in cancer treatment. In this review, we summarized and discussed the recent strategies to enhance drug delivery and release of carrier-free nanodrugs for improved cancer therapy, including optimizing the intrinsic physicochemical properties and external modification. Finally, the corresponding challenges that carrier-free nanodrugs faced are discussed and the future perspectives for its application are presented. We hope this review will provide constructive information for the rational design of more effective carrier-free nanodrugs to advance therapeutic treatment.

Progress in Colloid Delivery Systems for Protection and Delivery of Phenolic Bioactive Compounds: Two Study Cases-Hydroxytyrosol and Curcumin

Insufficient intake of beneficial food components into the human body is a major issue for many people. Among the strategies proposed to overcome this complication, colloid systems have been proven to offer successful solutions in many cases. The scientific community agrees that the production of colloid delivery systems is a good way to adequately protect and deliver nutritional components. In this review, we present the recent advances on bioactive phenolic compounds delivery mediated by colloid systems. As we are aware that this field is constantly evolving, we have focused our attention on the progress made in recent years in this specific field. To achieve this goal, structural and dynamic aspects of different colloid delivery systems, and the various interactions with two bioactive constituents, are presented and discussed. The choice of the appropriate delivery system for a given molecule depends on whether the drug is incorporated in an aqueous or hydrophobic environment. With this in mind, the aim of this evaluation was focused on two case studies, one representative of hydrophobic phenolic compounds and the other of hydrophilic ones. In particular, hydroxytyrosol was selected as a bioactive phenol with a hydrophilic character, while curcumin was selected as typical representative hydrophobic molecules.

A revised analysis of current and emerging Nano suspension technological approaches for cardiovascular medicine

Background

This is an objective critique to give an in-depth description of Nano suspensions. This article is attempting to address the issue of whether or not Nano science is realistic with respect to price, with regards to item costs being added to the endeavor and Lipotropic drugs have proven to be rewarding and Lipo-immunotherapy has proven to be beneficial. In modern times, drug marketing and promotion have become crucial to efficient commercializing of successful molecules, pharmaceutical companies often work to increase the chances of promoting successful drugs, these included cardiovascular drugs because of their widespread usage.

Main body

Nano suspension is a Nano metric Colloidal Suspension system i.e., Nano suspensions, in the solid form reaches the bloodstream and Nanoparticle colloids readily available to the target cells. All research on Nanostructures is focused on the four primary dimensions, composition, homogeneity, heterogeneity, elasticity, and agglomeration. Researchers are devising ways to deliver medication and other substances to a damaged cell and diseased region, as well as diagnose the body to pinpoint disease and defects, by way of Nanotechnology.

Short conclusions

The vital analysis of Nano science experiment on Nano suspension is working to achieve the goal of reducing product cost by using Nanotechnology in product development, as it wants to examine the probability of development by utilizing Nanotechnology. The usage of the top-limited technology allows the development of cardiovascular drugs classified under the biopharmaceutical classification system (Class II and Class IV) to use two approaches namely top-down and bottom-up methods.

The N-terminal tail of the hydrophobin SC16 is not required for rodlet formation

Hydrophobins are small proteins that are secreted by fungi, accumulate at interfaces, modify surface hydrophobicity, and self-assemble into large amyloid-like structures. These unusual properties make hydrophobins an attractive target for commercial applications as green emulsifiers and surface modifying agents. Hydrophobins have diverse sequences and tertiary structures, and depending on the hydrophobin, different regions of their structure have been proposed to be required for self-assembly. To provide insight into the assembly process, we determined the first crystal structure of a class I hydrophobin, SC16. Based on the crystal structure, we identified a putative intermolecular contact that may be important for rodlet assembly and was formed in part by the N-terminal tail of SC16. Surprisingly, removal of the N-terminal tail did not influence the self-assembly kinetics of SC16 or the morphology of its rodlets. These results suggest that other regions of this hydrophobin class are required for rodlet formation and indicate that the N-terminal tail of SC16 is amenable to modification so that functionalized hydrophobin assemblies can be created.

Towards principled design of cancer nanomedicine to accelerate clinical translation

Nanotechnology in medical applications, especially in oncology as drug delivery systems, has recently shown promising results. However, although these advances have been promising in the pre-clinical stages, the clinical translation of this technology is challenging. To create drug delivery systems with increased treatment efficacy for clinical translation, the physicochemical characteristics of nanoparticles such as size, shape, elasticity (flexibility/rigidity), surface chemistry, and surface charge can be specified to optimize efficiency for a given application. Consequently, interdisciplinary researchers have focused on producing biocompatible materials, production technologies, or new formulations for efficient loading, and high stability. The effects of design parameters can be studied in vitro, in vivo, or using computational models, with the goal of understanding how they affect nanoparticle biophysics and their interactions with cells. The present review summarizes the advances and technologies in the production and design of cancer nanomedicines to achieve clinical translation and commercialization. We also highlight existing challenges and opportunities in the field.

Nanobiotic formulations as promising advances for combating MRSA resistance: susceptibilities and post-antibiotic effects of clindamycin, doxycycline, and linezolid

Antimicrobial activity and post-antibiotic effects (PAEs) are both important parameters in determination of the dosage regimen of antimicrobial agents. In the present study, antimicrobial activity and PAEs of clindamycin, doxycycline, linezolid, and their nanobiotic formulations were evaluated against two methicillin resistant Staphylococcus aureus clinical isolates (MRSA) encoded (MRSA-S1 and MRSA-S2). Nanobiotic formulations increased the susceptibility of MRSA isolates by 4-64 folds as compared to their conventional ones. The PAE values were determined after exposure of MRSA isolates for 1 h to 10× the MICs of the tested antibiotics. The duration of PAEs were recorded after bacterial growth in Mueller Hinton broth (MHB) free from antibiotic has been restored. The PAE values for MRSA-S1 were 2.5 h for the conventional antibiotics. However, the PAEs for nanobiotics were 4 h for both clindamycin and linezolid, while 3 h for doxycycline. For MRSA-S2, linezolid and linezolid nanobiotics PAEs were 3 h. PAEs of clindamycin and clindamycin nanobiotics were 3.75 h and 4 h, respectively. Doxycycline and doxycycline nanobiotics revealed the same PAEs patterns of 3.5 h. The findings of the current study may positively influence the pharmacodynamics of the antibiotics and consequently the dosage regimen of nanobiotics as well as on their clinical outcome.

Hybrid membrane-coated nanosuspensions for multi-modal anti-glioma therapy via drug and antigen delivery

BACKGROUND

Glioma is one of the deadliest human cancers. Although many therapeutic strategies for glioma have been explored, these strategies are seldom used in the clinic. The challenges facing the treatment of glioma not only involve the development of chemotherapeutic drugs and immunotherapeutic agents, but also the lack of a powerful platform that could deliver these two moieties to the targeted sites. Herein, we developed chemoimmunotherapy delivery vehicles based on C6 cell membranes and DC membranes to create hybrid membrane-coated DTX nanosuspensions (DNS-[C6&DC]m).

RESULTS

Results demonstrated successful hybrid membrane fusion and nanosuspension functionalization, and DNS-[C6&DC]m could be used for different modes of anti-glioma therapy. For drug delivery, membrane coating could be applied to target the source cancer cells via a homotypic-targeting mechanism of the C6 cell membrane. For cancer immunotherapy, biomimetic nanosuspension enabled an immune response based on the professional antigen-presenting characteristic of the dendritic cell membrane (DCm), which carry the full array of cancer cell membrane antigens and facilitate the uptake of membrane-bound tumor antigens for efficient presentation and downstream immune n.

CONCLUSION

DNS-[C6&DC]m is a multifunctional biomimetic nano-drug delivery system with the potential to treat gliomas through tumor-targeted drug delivery combined with immunotherapy, thereby presenting a promising approach that may be utilized for multiple modes of cancer therapy.

A critical review on the particle generation and other applications of rapid expansion of supercritical solution

The novel particle generation processes of Active Pharmaceutical Ingredient (API)/drug have been extensively explored in recent decades due to their wide-range applications in the pharmaceutical industry. The Rapid Expansion of Supercritical Solutions (RESS) is one of the promising techniques to obtain the fine particles (micro to nano-size) of APIs with narrow particle size distribution (PSD). In RESS, supercritical carbon dioxide (SC CO₂) and API are used as solvent and solute respectively. In this literature survey, the application of RESS in the formation of fine particles is critically reviewed. Solubility of API in SC CO₂ and supersaturation are the key factors in tuning the particle size. The different approaches to model and predict the solubility of API in SC CO₂ are discussed. Then, the effect of process parameters on mean particle size and the particle size distribution are interpreted in the context of solubility and supersaturation. Furthermore, the less-explored applications of RESS in preparation of solid-lipid nanoparticles, liposome, polymorphic conversion, cocrystallization and inclusion complexation are compared with traditional processes. The solubility enhancement of API in SC CO₂ using co-solvent and its applications in particle generation are explored in published literature. The development and modifications in the conventional RESS process to overcome the limitations of RESS are presented. Finally, the perspective on RESS with special attention to its commercial operation is highlighted.

Spray-freeze-dried inhalable composite microparticles containing nanoparticles of combinational drugs for potential treatment of lung infections caused by Pseudomonas aeruginosa

The multi-drug resistance of Pseudomonas aeruginosa is an overwhelming cause of terminal and persistent lung infections in cystic fibrosis (CF) patients. Antimicrobial synergy has been shown for colistin and ivacaftor, and our study designed a relatively high drug-loading dry powder inhaler formulation containing nanoparticles of ivacaftor and colistin. The ivacaftor-colistin nanosuspensions (Iva-Col-NPs) were prepared by the anti-solvent method with different stabilizers. Based on the aggregation data, the formulation 7 (F7) with DSPG-PEG-OMe as the stabilizer was selected for further studies. The F7 consisted of ivacaftor, colistin and DSPG-PEG-OMe with a mass ratio of 1:1:1. The F7 powder formulation was developed using the ultrasonic spray-freeze-drying method and exhibited a rough surface with relatively high fine particle fraction values of 61.4 ± 3.4% for ivacaftor and 63.3 ± 3.3% for colistin, as well as superior emitted dose of 97.8 ± 0.3% for ivacaftor and 97.6 ± 0.5% for colistin. The F7 showed very significant dissolution improvement for poorly water soluble ivacaftor than the physical mixture. Incorporating two drugs in a single microparticle with synchronized dissolution and superior aerosol performance will maximize the synergy and bioactivity of those two drugs. Minimal cytotoxicity in Calu-3 human lung epithelial cells and enhanced antimicrobial activity against colistin-resistant P. aeruginosa suggested that our formulation has potential to improve the treatment of CF patients with lung infections.

Novel extraction, rapid assessment and bioavailability improvement of quercetin: A review

Quercetin (QUR) have got the attention of scientific society frequently due to their wide range of potential applications. QUR has been the focal point for research in various fields, especially in food development. But, the QUR is highly unstable and can be interrupted by using conventional assessment methods. Therefore, researchers are focusing on novel extraction and non-invasive tools for the non-destructive assessment of QUR. The current review elaborates the different novel extraction (ultrasound-assisted extraction, microwave-assisted extraction, supercritical fluid extraction, and enzyme-assisted extraction) and non-destructive assessment techniques (fluorescence spectroscopy, terahertz spectroscopy, near-infrared spectroscopy, hyperspectral imaging, Raman spectroscopy, and surface-enhanced Raman spectroscopy) for the extraction and identification of QUR in agricultural products. The novel extraction approaches facilitate shorter extraction time, involve less organic solvent, and are environmentally friendly. While the non-destructive techniques are non-interruptive, label-free, reliable, accurate, and environmental friendly. The non-invasive spectroscopic and imaging methods are suitable for the sensitive detection of bioactive compounds than conventional techniques. QUR has potential therapeutic properties such as anti-obesity, anti-diabetes, antiallergic, antineoplastic agent, neuroprotector, antimicrobial, and antioxidant activities. Besides, due to the low bioavailability of QUR innovative drug delivery strategies (QUR loaded gel, QUR polymeric micelle, QUR nanoparticles, glucan-QUR conjugate, and QUR loaded mucoadhesive nanoemulsions) have been proposed to improve its bioavailability and providing novel therapeutic approaches.

Recent progress on Pickering emulsions stabilized by polysaccharides-based micro/nanoparticles

Pickering emulsions stabilized by micro/nanoparticles have attracted considerable attention owing to their great potential in various applications ranging from cosmetic and food industries to catalysis, tissue engineering and drug delivery. There is a growing demand to design "green" micro/nanoparticles for constructing stable Pickering emulsions. Micro/nanoparticles derived from the naturally occurring polysaccharides including cellulose, chitin, chitosan and starch are capable of assembling at oil/water interfaces and are promising green candidates because of their excellent biodegradability and renewability. The physicochemical properties of the micro/nanoparticles, which are determined by the fabricating approaches and/or post-modification methods, have a significant effect on the characteristics of the final Pickering emulsions and their applications. Herein, recent advances on Pickering emulsions stabilized by polysaccharides-based micro/nanoparticles and the construction of functional materials including porous foams, microcapsules and latex particles from these emulsions as templates, are reviewed. In particular, the effects of micro/nanoparticles properties on the characteristics of the Pickering emulsions and their applications are discussed. Furthermore, the obstacles that hinder the practical applications of polysaccharides-based micro/nanoparticles and Pickering emulsions as well as the prospects for the future development, are discussed.

Preparation and Pharmacokinetic Characterization of an Anti-Virulence Compound Nanosuspensions

Antibiotic resistance has become a worldwide public health threat due to the rapid evolution and spread of antibiotic-resistant bacteria. CCG-211790 is a novel anti-virulence compound that does not kill bacteria but could ameliorate human diseases by inhibiting expression of virulence factors, thereby applying less selection pressure for antibiotic resistance. However, its potential clinical use is restricted because of its poor aqueous solubility, resulting in formulation challenges. Nanosuspension technology is an effective way to circumvent this problem. Nanosuspensions of CCG-211790 with two different particle sizes, NanoA (315 ± 6 nm) and NanoB (915 ± 24 nm), were prepared using an antisolvent precipitation-ultrasonication method with Tween 80 as the stabilizer. Particle and pharmacokinetics (PK) of CCG-211790 nanosuspensions were characterized. Both NanoA and NanoB demonstrated remarkable increases in dissolution rate compared with the bulk compound. The PK parameters of NanoA were comparable to those of CCG-211790 solution formulation in intravenous or oral administration, suggesting that CCG-211790 nanosuspensions with smaller particle size improved oral bioavailability and drug exposure compared to traditional formulations of drug candidates.

Polysaccharide-Based Micro- and Nanosized Drug Delivery Systems for Potential Application in the Pediatric Dentistry

The intensive development of micro- and nanotechnologies in recent years has offered a wide horizon of new possibilities for drug delivery in dentistry. The use of polymeric drug carriers turned out to be a very successful technique for formulating micro- and nanoparticles with controlled or targeted drug release in the oral cavity. Such innovative strategies have the potential to provide an improved therapeutic approach to prevention and treatment of various oral diseases not only for adults, but also in the pediatric dental practice. Due to their biocompatibility, biotolerance and biodegradability, naturally occurring polysaccharides like chitosan, alginate, pectin, dextran, starch, etc., are among the most preferred materials for preparation of micro- and nano-devices for drug delivery, offering simple particle-forming characteristics and easily tunable properties of the formulated structures. Their low immunogenicity and low toxicity provide an advantage over most synthetic polymers for the development of pediatric formulations. This review is focused on micro- and nanoscale polysaccharide biomaterials as dental drug carriers, with an emphasis on their potential application in pediatric dentistry.

Pulmonary Delivery of Curcumin and Beclomethasone Dipropionate in a Multicomponent Nanosuspension for the Treatment of Bronchial Asthma

Curcumin has shown a potential extraordinary activity as an add-on ingredient in asthma treatment, due to its immunomodulatory and anti-inflammatory mechanism of action. However, its low water solubility and bioavailability lead to a poor therapeutic effect, which can be overcome by its formulation as nanocrystals. The aim of this study was to prepare a multicomponent formulation for the delivery of curcumin (CUR) and beclomethasone dipropionate (BDP) into the lungs as water-based nanosuspensions (NS). Single component formulations (CUR-NS, BDP-NS) and a multicomponent formulation (CUR+BDP-NS) were prepared through a wet ball media milling technique, using P188 as a non-toxic stabilizer. Characterization was carried out in terms of size, size distribution, zeta potential, nanocrystals morphology, and solid-state properties. Moreover, the inhalation delivery efficiency was studied with Next Generation Impactor (NGI, Apparatus E Ph. Eu). CUR-NS was optimized and showed a long-term stability and improved nanocrystals apparent solubility. The three formulations exhibited a nanocrystal mean diameter in the range of 200-240 nm and a homogenous particle size distribution. Aggregation or sedimentation phenomena were not observed in the multicomponent formulation on 90 days storage at room temperature. Finally, the nebulization tests of the three samples showed optimal aerodynamic parameters and MMAD < 5 µm.

Application of Nanomaterials in the Treatment and Diagnosis of Ophthalmology Diseases

Eye diseases often lead to impaired vision and seriously affect the daily life of patients. Local administration of ophthalmic drugs is one of the most important approaches for the treatment of ophthalmic diseases. However, due to the special biochemical environment of the ocular tissue and the existence of many barriers, the bioavailability of conventional ophthalmic preparations in the eye is very low. Nanomaterials can be utilized as carriers of drugs, which can improve the absorption, distribution, metabolism and bioavailability of drugs in eyes. Nanomaterials have also the advantages of small size, simple preparation, good degradability, strong targeting, and little stimulation to biological tissues, providing an innovative and practical method for the drug delivery of ophthalmic diseases. In addition, nanomaterials can be used as an auxiliary means for early diagnosis of ophthalmic diseases by improving the specificity and accuracy of detection methods. Nanomaterials help clinicians and researchers delve deeper into the physiology and pathology of the eye at the nanoscale. We summarize the application of nanomaterials in the diagnosis and treatment of ophthalmic diseases in this review.

Exploring micellar-based polymeric systems for effective nose-to-brain drug delivery as potential neurotherapeutics

Non-invasive nose-to-brain delivery presents a competitive strategy for effective drug targeting. This strategy can potentially evade the blood-brain barrier (BBB) depending on the pathway the drug and/or drug/micelle composite travels, thereby allowing direct drug delivery to the brain. This delivery strategy was employed for lurasidone, a clinically USFDA-approved neurotherapeutic molecule in bipolar disorders and schizophrenia treatments. The aim of this study was to develop mixed polymeric micelles of lurasidone HCl (LH) for targeted brain delivery via intranasal route. Lurasidone HCl-loaded mixed micelles (LHMM) were prepared by solvent evaporation method and optimized by 3² factorial design to quantify the effects of excipients on micelle size and entrapment efficiency. Fourier transform infrared spectroscopy helped in scrutinizing drug-excipient interactions whereas transmission electron microscopy images showed particle size and shape. Further, LHMM and LHMM hydrogel were evaluated for in vitro diffusion, histopathology, ex vivo permeation, in vivo pharmacokinetics and stability studies. Optimized LHMM exhibited 175 nm particle size and 97.8% entrapment efficiency with improved in vitro drug diffusion (81%). LHMM hydrogel showed 79% ex vivo drug permeation without any significant signs of nasociliary toxicity to sheep nasal mucosa. Single dose in vivo pharmacokinetic studies showed improved therapeutic concentration of drug in the brain post intranasal administration with 9.5 ± 0.21 μg/mL C_max and T_1/2 of 19.1 ± 0.08 h as compared to pure drug. LHMM, when administered by intranasal route, demonstrated significant increase in the drug targeting efficiency as well as potential (%DTE and %DTP) of drug as compared to pure lurasidone. Thus, nanosized mixed micelles were useful in effective brain delivery of lurasidone HCl via intranasal route. Graphical abstract.

Essential Oil-Loaded NLC for Potential Intranasal Administration

Complementary and alternative medicines represent an interesting field of research on which worldwide academics are focusing many efforts. In particular, the possibility to exploit pharmaceutical technology strategies, such as the nanoencapsulation, for the delivery of essential oils is emerging as a promising strategy not only in Italy but also all over the world. The aim of this work was the development of nanostructured lipid carriers (NLC) for the delivery of essential oils (Lavandula, Mentha, and Rosmarinus) by intranasal administration, an interesting topic in which Italian contributions have recently increased. Essential oil-loaded NLC, projected as a possible add-on strategy in the treatment of neurodegenerative diseases, were characterized in comparison to control formulations prepared with Tegosoft CT and Neem oil. Homogeneous (polydispersity index, PDI < 0.2) nanoparticles with a small size (<200 nm) and good stability were obtained. Morphological and physical-chemical studies showed the formation of different structures depending on the nature of the liquid oil component. In particular, NLC prepared with Lavandula or Rosmarinus showed the formation of a more ordered structure with higher cytocompatibility on two cell lines, murine and human fibroblasts. Taken together, our preliminary results show that optimized positively charged NLC containing Lavandula or Rosmarinus can be proposed as a potential add-on strategy in the treatment of neurodegenerative diseases through intranasal administration, due to the well-known beneficial effects of essential oils and the mucoadhesive properties of NLC.

Terpenoids' anti-cancer effects: focus on autophagy

Terpenoids are the largest class of natural products, most of which are derived from plants. Amongst their numerous biological properties, their anti-tumor effects are of interest for they are extremely diverse which include anti-proliferative, apoptotic, anti-angiogenic, and anti-metastatic activities. Recently, several in vitro and in vivo studies have been dedicated to understanding the 'terpenoid induced autophagy' phenomenon in cancer cells. Light has already been shed on the intricacy of apoptosis and autophagy relationship. This latter crosstalk is driven by the delicate balance between activating or silencing of certain proteins whereby the outcome is expressed via interrelated signaling pathways. In this review, we focus on nine of the most studied terpenoids and on their cell death and autophagic activity. These terpenoids are grouped in three classes: sesquiterpenoid (artemisinin, parthenolide), diterpenoids (oridonin, triptolide), and triterpenoids (alisol, betulinic acid, oleanolic acid, platycodin D, and ursolic acid). We have selected these nine terpenoids among others as they belong to the different major classes of terpenoids and our extensive search of the literature indicated that they were the most studied in terms of autophagy in cancer. These terpenoids alone demonstrate the complexity by which these secondary metabolites induce autophagy via complex signaling pathways such as MAPK/ERK/JNK, PI3K/AKT/mTOR, AMPK, NF-kB, and reactive oxygen species. Moreover, induction of autophagy can be either destructive or protective in tumor cells. Nevertheless, should this phenomenon be well understood, we ought to be able to exploit it to create novel therapies and design more effective regimens in the management and treatment of cancer.

Pharmaceutical nanocrystals: A promising approach for improved topical drug delivery

The barrier function of skin and non-optimal physicochemical properties of drug present a challenge to skin penetration of many drugs, thus motivating the development of novel drug delivery systems. Recently, nanocrystal-based formulations have been investigated for topical drug delivery and demonstrated improved skin penetration. This review highlights barriers in skin penetration, current techniques to improve topical delivery and application of nanocrystals in conquering obstacles for topical delivery. Nanocrystals can improve delivery through the skin by mechanisms like higher concentration gradient across skin resulting in increased passive diffusion, hair follicle targeting, diffusional corona and adhesion to skin. This would be of interest for formulation scientists for product development of molecules that are 'difficult-to-deliver' topically.

Oregano and Thyme Essential Oils Encapsulated in Chitosan Nanoparticles as Effective Antimicrobial Agents against Foodborne Pathogens

The use of natural compounds with biocidal activity to fight the growth of bacteria responsible for foodborne illness is one of the main research challenges in the food sector. This study reports the preparation and physicochemical characterization of chitosan nanoparticles loaded with Thymus capitatus (Th-CNPs) and Origanum vulgare (Or-CNPs) essential oils. The nanosystems were obtained by ionotropic gelation technique with high encapsulation efficiency (80-83%) and loading capacity (26-27%). Nanoparticles showed a spherical shape, bimodal particle size distribution, and good stability (zeta potential values > 40 mV). The treatment of the nanosuspensions at different temperatures (4 and 40 °C) and storage times (7, 15, 21, and 30 days) did not affect their physicochemical parameters and highlights their reservoir ability for essential oils also under stressful conditions. Both Or-CNPs and Th-CNPs exhibited an enhanced bactericidal activity against foodborne pathogens (S. aureus, E. coli, L. monocytogenes) than pure essential oils. These ecofriendly nanosystems could represent a valid alternative to synthetic preservatives and be of interest for health and food safety.

Zoxamide accumulation and retention evaluation after nanosuspension technology application in tomato plant

BACKGROUND

Low water solubility of pesticide requires formulations with high levels of stabilizers and organic solvents. Moreover, only 0.1% of the applied pesticides formulation reaches the target, while 99.9% spreads in the surrounding environment. Therefore, there is the need for more efficient and environmentally sustainable alternatives.

RESULTS

Zoxamide (ZO) nanosuspension was prepared through a media milling technique by using the stabilizer polysorbate 80. The thin and acicular crystals obtained, showed particle size of 227 nm, polydispersion index of 0.247 and zeta potential of -28 mV. Dimensional data and morphology of ZO nanocrystals alone, on tomato leaves and berries, were confirmed by scanning electron microscopy. The reduction in size for ZO crystals obtained after the milling process increased pesticide water solubility till 39.6 mg L^-1 , about 1.6 the solubility obtained with a conventional commercial formulation. Field and dip contamination trials performed on tomato plants showed the nanosuspension's ability to increase ZO deposition and accumulation versus a coarse ZO suspension and commercial formulation, respectively.

CONCLUSIONS

The nanoformulation proposed, resulted in low cost and was easy to make. Moreover, the organic solvent-free composition together with a low surfactant addition assured a minor environmental impact. Finally, the increased retention and deposition of the fungicide can reduce the amounts of ZO formulation applied to tomatoes. © 2021 Society of Chemical Industry.

Crystallization Risk Assessment of Amorphous Solid Dispersions by Physical Shelf-Life Modeling: A Practical Approach

Amorphous solid dispersions (ASDs) of a poorly water-soluble active pharmaceutical ingredient (API) in a polymer matrix can enhance the water solubility and therefore generally improve the bioavailability of the API. Although examples of long-term stability are emerging in the literature, many ASD products are kinetically stabilized, and inhibition of crystallization of a drug substance within and beyond shelf life is still a matter of debate, since, in some cases, the formation of crystals may impact bioavailability. In this study, a risk assessment of API crystallization in packaged ASD drug products and a mitigation strategy are outlined. The risk of shelf-life crystallization and the respective mitigation steps are assigned for different drug product development scenarios and the scientific principles of each step are discussed. Ultimately, the physical stability of ASD drug products during shelf-life storage is modeled. The methodology is based on the quantification of crystal growth kinetics by transmission Raman spectroscopy (TRS), modeling the impact of water sorption on the glass-transition temperature of the ASD, and the prediction of moisture uptake by the packaged ASD drug product during storage. This approach is applied to an ASD of fenofibrate that features both fast API crystallization under accelerated storage conditions and long-term stability in a suitable protective packaging under conventional storage conditions.

Production and isolation of pharmaceutical drug nanoparticles

Nanosizing of pharmaceutical drug particles is one of the most important drug delivery platforms approaches for the commercial development of poorly water-soluble drug molecules. Though nanosizing of drug particles has been proven to greatly enhance drugs dissolution rate and apparent solubility, nanosized materials have presented significant challenges for their formulation as solid dosage forms (e.g. tablets, capsules). This is due to the strong Van der Waals attraction forces between dry nanoparticles leading to aggregation, cohesion, and consequently poor flowability. In this review, the broad area of nanomedicines is overviewed with the primary focus on drug nanocrystals and the top-down and bottom-up methods used in their fabrication. The review also looks at how nanosuspensions of pharmaceutical drugs are generated and stabilised, followed by subsequent strategies for isolation of the nanoparticles. A perspective on the future outlook for drug nanocrystals is also presented.

Etravirine-loaded dissolving microneedle arrays for long-acting delivery

A key challenge of HIV treatment with multiple antiretroviral drugs is patient adherence. Thus, there is an urgent need for long-acting depot systems for delivering drugs over an extended duration. Although the parenteral route is preferred for depot systems, it is associated with obvious drawbacks, such as painful injections, potentially-contaminated sharps waste, and the necessity of trained healthcare personnel for administration. Amongst a small number of alternatives in development microneedles are versatile delivery systems enabling systemic drug delivery and potentially improving patient adherence due to their capacity for self-administration. We have developed dissolving microneedle (DMNs) embedded with etravirine nanosuspension (ETR NS) as a long-acting HIV therapy to improve patient adherence. The ETR NS prepared by sonoprecipitation yielded particle sizes of 764 ± 96.2 nm, polydispersity indices of of 0.23 ± 0.02, and zeta potentials of -19.75 ± 0.55 mV. The DMNs loaded with ETR NS demonstrated 12.84 ± 1.33% ETR deposition in ex-vivo neonatal porcine skin after 6 h application. In in vivo rat pharmacokinetic studies, the Cmax exhibited by DMNs loaded with ETR powder and ETR NS were 158 ± 10 ng/mL and 177 ± 30 ng/mL, respectively. DMN groups revealed a higher t_1/2, Tmax, and mean residence time compared to intravenous ETR solutions, suggesting the long-acting potential of etravirine delivered intradermally using DMNs.

In Vitro Caco-2 Cell Permeability Studies of Ziprasidone Hydrochloride Monohydrate Nanocrystals

Objectives

The current study focused on the evaluation of the cytotoxic effect and permeability of ziprasidone hydrochloride monohydrate (ZHM) nanocrystals on Caco-2 cells.

Materials and Methods

ZHM nanocrystals were prepared by the microfluidization method in the presence of polyvinylpyrrolidone as a stabilizer. Particle size (PS), particle size distribution (PDI), and zeta potential (ZP) values were measured in characterization studies. In vitro cytotoxic effects of ZHM nanocrystals were investigated using the 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. Caco-2 transport studies were conducted with formulations of ZHM coarse powder and nanocrystals.

Results

Nanocrystals were obtained with 400-600 nm PS, 0.1-0.4 PDI, and >20 mV ZP values. The cell viability remained 100% for all sample groups. The permeability value of ZHM nanocrystals through Caco-2 cells increased 2.3-fold in comparison with ZHM coarse powder. Cumulative drug transport also increased at the end of the sampling period.

Conclusion

Nanocrystal technology helps to increase the permeability of drug particles by increasing the saturation solubility.

Nanosuspension coated multiparticulates for controlled delivery of albendazole

OBJECTIVE

Improving solubility and bioavailability of albendazole (ALB).

SIGNIFICANCE

ALB is a broad-spectrum anthelminthic BCS class II drug with aqueous solubility of solubility of 4.1 mg/l at 25 °C and oral bioavailability of <5%.

METHODS

ALB nanosuspensions (NSs) were prepared by evaporative antisolvent precipitation using tocopherol polyethylene glycol succinate (TPGS) and polyvinyl pyrrolidone (PVP) as stabilizers and characterized for particle size, polydispersity index, and zeta potential. 3² factorial design was used to investigate effect of stabilizer concentration and speed of stirring on particle size. Concentration of TPGS was varied from 0.03 to 0.05% w/v and PVP K-30 was constant at 0.04% w/v. Stirring speed range was 1000-3000 rpm. Optimized NS was loaded on Espheres and coated with Eudragit S10& L100 and studied for friability, surface morphology and release kinetics.

RESULTS

Factorial experiments revealed pronounced effect of TPGS on particle size. Optimized batch had particle size of 251 ± 7.2 nm and zeta potential -16.2 ± 2.68 mV. Saturation solubility showed increase of 16-fold in water whereas in phosphate buffer increase was fourfold. ALB-NS secondary coated Espheres released 94.3% drug in 10 h whereas ALB-MS (microsuspension) coated Espheres showed 58% release. A 1.3-fold increase in AUC_0-10h was evident. Permeation from ALB-NS coated Espheres was 32% in 60 min while for ALB-MS coated Espheres it was 20%. Permeation increase occurred due to presence of TPGS which acts as a permeation enhancer.

Generation of Ophthalmic Nanosuspension of Prednisolone Acetate Using a Novel Technology

PURPOSE

Prednisolone Acetate (PAC) is currently marketed as micronized ophthalmic suspension. The microsuspension has poor dose accuracy and efficacy due to aggregation, slow dissolution rate and limited corneal residence. The ophthalmic nanosuspension of PAC shall show enhanced solubility, dissolution rate and corneal adhesion due to small particle size and increased surface area.

METHODS

In the current work, we prepared ophthalmic formulation of PAC using a novel, spray drying based technology. Firstly, PAC nanocrystalline solid dispersions (NCSD) were prepared using Mannitol (MAN) as the crystallization inducing excipient and two separate stabilizers, Polyvinyl Alcohol (PAC_MAN_PVA) and Vitamin E Tocopheryl Polyethylene Glycol Sulphosuccinate (PAC_MAN_TPGS). The NCSD was dispersed in an aqueous vehicle to obtain an ophthalmic nanosuspension.

RESULTS

The composition, PAC_MAN_PVA (0.3:0.67:0.03%), was pursued due to absence of crystal growth on storage at 40°C/75%RH for 3 months. The resulting nanosuspension showed crystal size, osmolality and viscosity of 590 ± 165 nm, 297 ± 6 mOsm/L and 11 ± 8cP respectively. In 1%w/v SLS media, the nanosuspension showed rapid and complete dissolution of PAC in 120 s. Ex-vivo goat corneal permeation and adhesion study revealed that in comparison to microsuspension, a higher fraction (6.2 times) of nanosuspension adhered to the cornea. Safety studies performed using corneal histopathology and Hen Egg Test- Chorio Allantoic Membrane (HET-CAM) assay showed no physical change in cornea or capillary damage, respectively.

CONCLUSIONS

The NCSD can be explored for generation of ophthalmically acceptable nanosuspensions of poorly soluble drugs.

Characterization and Applications of Colloidal Systems as Versatile Drug Delivery Carriers for Parenteral Formulations

Preparing a suitable formulation for parenteral administration is already a difficult task; this, coupled with poor water-soluble new chemical entity (NCE), complicates this situation even further. There are several methodologies available to enhance water solubility, but this alone does not entail successful formulation. Making a micro/nano emulsion with a suitable surfactant not only increases the drug solubility but also the cell membrane permeability. Thus, not only biopharmaceutic classification system (BCS)-II (low solubility compounds) but also BCS-III (low permeability) and BCS-IV drugs (low solubility and low permeability) can be further exploited. Those drug candidates otherwise will not move further in NCE evaluation or clinical trials. This succinct review article delves into various aspects of biphasic micro/nano emulsion systems for parenteral drug delivery including the structure of the biphasic colloidal systems, characterization parameters, stability issues, regulatory considerations, and applications in life sciences.

A study of hydrophobins-modified menaquinone-7 on osteoblastic cells differentiation

Menaquinone-7 is involved in bone metabolism and can be used to prevent and treat osteoporosis. However, as a fat-soluble vitamin, menaquinone-7 has poor water solubility. As a surfactant, hydrophobins can change the affinity/hydrophobicity of the covered interface. In this study, menaquinone-7 was modified by hydrophobins, and the different addition ratios were explored. Moreover, Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and water contact angle (WCA) measurements indicated that hydrophobins effectively bind to menaquinone-7 and greatly increase the hydrophilicity of the surface of menaquinone-7. Studies on the metabolism of MC3T3-E1 cells showed that compared with native menaquinone-7, HGFI-modified menaquinone-7 can significantly promote osteoblast differentiation but inhibit osteoclast differentiation. Besides, the Mito-Tracker Green experiments show that HGFI-modified menaquinone-7 can significantly promote the activity of mitochondria in cells. These findings indicate that hydrophobins can be used as an effective biomaterial to modify menaquinone-7, promote the formation of osteoblasts, and better to bone balance.

Delivery of beclomethasone dipropionate nanosuspensions with an electronic cigarette

The aim of this work was to ascertain the ability of electronic nicotine delivery systems (ENDS) to deliver drug nanocrystals through the produced aerosol. A nanocrystal nanosuspension of beclomethasone dipropionate, a synthetic chlorinated corticosteroid diester commonly used by inhalation in the treatment of asthma and chronic obstructive pulmonary disease, was prepared with a wet media milling technique using Poloxamer 188 as stabilizer. The obtained nanosuspension was thoroughly characterized by different techniques: transmission electron microscopy, photon correlation spectroscopy, X-ray powder diffractometry and Fourier transform infrared spectroscopy. The nanosuspension was then loaded in the cartomizer of the electronic cigarette and the produced aerosol was collected and analysed, confirming the presence of drug nanocrystals. The results of this study suggested the possible alternative use of ENDS as medical device for the delivery of poorly soluble drugs.

Emerging Nano-Formulations and Nanomedicines Applications for Ocular Drug Delivery

Ocular diseases can deteriorate vision to the point of blindness and thus can have a major impact on the daily life of an individual. Conventional therapies are unable to provide absolute therapy for all ocular diseases due to the several limitations during drug delivery across the blood-retinal barrier, making it a major clinical challenge. With recent developments, the vast number of publications undergird the need for nanotechnology-based drug delivery systems in treating ocular diseases. The tool of nanotechnology provides several essential advantages, including sustained drug release and specific tissue targeting. Additionally, comprehensive in vitro and in vivo studies have suggested a better uptake of nanoparticles across ocular barriers. Nanoparticles can overcome the blood-retinal barrier and consequently increase ocular penetration and improve the bioavailability of the drug. In this review, we aim to summarize the development of organic and inorganic nanoparticles for ophthalmic applications. We highlight the potential nanoformulations in clinical trials as well as the products that have become a commercial reality.

Linking In Vitro Intrinsic Dissolution Rate and Thermodynamic Solubility with Pharmacokinetic Profiles of Bedaquiline Long-Acting Aqueous Microsuspensions in Rats

Pharmacokinetic (PK) profiles of a range of bedaquiline (BDQ) long-acting injectable (LAI) microsuspensions in rats after parenteral (i.e., intramuscular and subcutaneous) administration were correlated with the in vitro intrinsic dissolution rate (IDR) and thermodynamic solubility of BDQ in media varying in surfactant type and concentration to better understand the impact of different nonionic surfactants on the in vivo performance of BDQ LAI microsuspensions. All LAI formulations had a similar particle size distribution. The investigated surfactants were d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), poloxamer 338, and poloxamer 188. Furthermore, the relevance of medium complexity by using a biorelevant setup to perform in vitro measurements was assessed by comparing IDR and thermodynamic solubility results obtained in biorelevant media and formulation vehicle containing different surfactants in varying concentrations. In the presence of a surfactant, both media could be applied to obtain in vivo representative dissolution and solubility data because the difference between the biorelevant medium and formulation vehicle was predominantly nonsignificant. Therefore, a more simplistic medium in the presence of a surfactant was preferred to obtain in vitro measurements to predict the in vivo PK performance of LAI aqueous suspensions. The type of surfactant influenced the PK profiles of BDQ microsuspensions in rats, which could be the result of a surfactant effect on the IDR and/or thermodynamic solubility of BDQ. Overall, two surfactant groups could be differentiated: TPGS and poloxamers. Most differences between the PK profiles (i.e., maximum concentration observed, time of maximum concentration observed, and area under the curve) were observed during the first 21 days postdose, the time period during which particles in the aqueous suspension are expected to dissolve.

Recent Advances in Oral Nano-Antibiotics for Bacterial Infection Therapy

Bacterial infections are the main infectious diseases and cause of death worldwide. Antibiotics are used to treat various infections ranging from minor to life-threatening ones. The dominant route to administer antibiotics is through oral delivery and subsequent gastrointestinal tract (GIT) absorption. However, the delivery efficiency is limited by many factors such as low drug solubility and/or permeability, gastrointestinal instability, and low antibacterial activity. Nanotechnology has emerged as a novel and efficient tool for targeting drug delivery, and a number of promising nanotherapeutic strategies have been widely explored to overcome these obstacles. In this review, we explore published studies to provide a comprehensive understanding of the recent progress in the area of orally deliverable nano-antibiotic formulations. The first part of this article discusses the functions and underlying mechanisms by which nanomedicines increase the oral absorption of antibiotics. The second part focuses on the classification of oral nano-antibiotics and summarizes the advantages, disadvantages and applications of nanoformulations including lipid, polymer, nanosuspension, carbon nanotubes and mesoporous silica nanoparticles in oral delivery of antibiotics. Lastly, the challenges and future perspective of oral nano-antibiotics for infection disease therapy are discussed. Overall, nanomedicines designed for oral drug delivery system have demonstrated the potential for the improvement and optimization of currently available antibiotic therapies.

Nanosuspensions and Microneedles Roller as a Combined Approach to Enhance Diclofenac Topical Bioavailability

Topical application of the anti-inflammatory drug diclofenac (DCF) reduces the severity of systemic unwanted effects compared to its oral administration. A number of transdermal formulations are available on the market and routinely used in clinical and home-care settings. However, the amount of DCF delivered across the skin remains limited and often insufficient, thus making the oral route still necessary for achieving sufficient drug concentration at the inflamed site. In attempting to improve the transdermal penetration, we explored the combined use of DCF nanosuspensions with a microneedle roller. Firstly, DCF nanosuspensions were prepared by a top-down media milling method and characterized by spectroscopic, thermal and electron microscopy analyses. Secondly, the pore-forming action of microneedle rollers on skin specimens (ex vivo) was described by imaging at different scales. Finally, DCF nanosuspensions were applied on newborn pig skin (in vitro) in combination with microneedles roller treatment, assessing the DCF penetration and distribution in the different skin layers. The relative contribution of microneedle length, nanosuspension stabilizer and application sequence could be identified by systemically varying these parameters.

Cell-tailored calcium carbonate particles with different crystal forms from nanoparticle to nano/microsphere

Inspired by biomineralization, the first synthesis of size-tunable calcium carbonates from nanoparticles (YC-CaCO3 NPs) to nano/microspheres (YC-CaCO3 N/MSs) with a porous structure was accomplished using a facile method under the mediation of the secretion from yeast cells (YCs). The biomolecules derived from the secretion of YCs were used as conditioning and stabilizing agents to control the biosynthesis of the YC-CaCO3 materials. The morphology and crystal forms of YC-CaCO3 materials can be affected by the biomolecules from the secretion of YCs. With increasing concentrations of biomolecules, the morphologies of the obtained CaCO3 materials changed from nanoparticles to nano/microspheres with a porous structure, while the crystal forms transformed from amorphous to calcite. Functional investigations showed that YC-CaCO3 NSs with a porous structure effectively acted as anticancer drug carriers with accurate and selective drug release in tumor tissue, which suggests that they have great potential to function as a therapeutic delivery system. These application features are mainly attributed to the satisfactory biocompatibility and biodegradability, high drug-loading capacity, and pH-dependent sustained drug release performance of the porous YC-CaCO3 NSs. The biomimetic synthesis strategy of YC-CaCO3 materials mediated by YC secretion not only helps to shed light on the biomineralization mechanism in organisms, but may also lead to a new means of biosynthesizing organic-inorganic nanocomposites.