Relationship between particle size and lung retention time of intact solid lipid nanoparticle suspensions after pulmonary delivery

The relationship between the particle size and lung retention time of inhaled nanocarriers was unclear, and this uncertainty hampered the design of nanocarriers for pulmonary delivery. The debate resulted from a lack of knowledge regarding the integrity of the involved nanocarriers. A distinguishable bioimaging probe which could differentiate between integrated and disintegrated nanocarriers by emitting different signals was introduced to address this problem. The aza-BODIPY structured aggregation-caused quenching (ACQ) probes were promising candidates, because they showed intense fluorescence signals in intact nanocarriers while quenched after the decomposition of nanocarriers. This attribute was called an on-off switch. In this paper, ACQ probes were encapsulated into a solid lipid nanoparticle suspension (SLNS) with different particle sizes (120-480 nm), and the relationship between particle size and lung retention time after pulmonary delivery was investigated in BALB/c mice. The results showed that a larger particle size led to a longer lung retention time. By comparing with the results of a non-water-quenching probe, the SLNS systems were found to be mostly intact in the pulmonary region. These findings will serve as a firm basis for the design and development of nanocarriers for pulmonary delivery.

Anhydrous reverse micelle nanoparticles: new strategy to overcome sedimentation instability of peptide-containing pressurized metered-dose inhalers

The objective of this study was to develop a novel anhydrous reverse micelle nanoparticles (ARM-NPs) system to overcome the sedimentation instability of peptide-containing pressurized metered-dose inhalers (pMDIs). A bottom-up method was utilized to fabricate ARM-NPs. Tertiary butyl alcohol (TBA)/water system, freeze-drying and lipid inversion method were successively used to produce the ARM-NPs for pMDI. Various characteristics of ARM-NPs were investigated including particle size, morphology, secondary structure of the peptide drug, aerosolization properties and storage stability. As revealed by the results, ARM-NPs with spherical shape possessed 147.7 ± 2.0 nm of particle size with 0.152 ± 0.021 PdI. The ARM-NPs for pMDI had satisfactory fine particle fraction (FPF) value of 46.99 ± 1.33%, while the secondary structure of the peptide drug was unchanged. Stability tests showed no pronounced sedimentation instability for over 12 weeks at 4-6 °C. Furthermore, a hypothesis was raised to explain the formation mechanism of ARM-NPs, which was verified by the differential scanning calorimetry analysis. The lecithin employed in the reverse micelle vesicles could serve as a steric barrier between peptide drugs and bulk propellant, which prevented the instability of peptide drugs in hydrophobic environment. Homogenous particle size could avoid Ostwald ripening phenomenon of particles in pMDIs. It was concluded that the ARM-NPs for pMDI could successfully overcome sedimentation instability by the steric barrier effect and homogeneous particle size.

Dry powder inhaler formulations of poorly water-soluble itraconazole: A balance between in-vitro dissolution and in-vivo distribution is necessary

Formulating poorly water-soluble drug, itraconazole (ITZ), as dry powder inhaler (DPI) may be more effective for the treatment of invasive pulmonary Aspergillosis than intravenous injection and oral administration. It is necessary to improve the dissolution of ITZ because the alveolar lining fluid is limited and thus the dissolution of ITZ in the lung may be slow and incomplete. However, too fast dissolution may result in over-absorption into the circulation and thus insufficient distribution in the lung. The purpose of this study is to understand the relationship between in-vitro dissolution and in-vivo distribution of ITZ from DPI formulations. Two DPI formulations (F1 and F2) with identical compositions and similar aerodynamic behaviors were fabricated by hot melt extrusion and thus jet-milling. ITZ was formulated with mannitol as fine solid crystal suspension system to effectively improve its dissolution. In-vitro dissolution tests and in-vivo pharmacokinetic studies indicated that F1 released faster than F2 under both sink and non-sink conditions, but exhibited a lower lung retention and higher plasma absorption than F2. These results suggested that although dissolution enhancement of poorly water-soluble drugs in pulmonary delivery may be necessary to overcome problems such as local irritation and quick elimination by macrophages, it may have an impact on the distribution of the drug between the lung and the plasma. A balance between airway dissolution and systemic absorption should be taken into consideration when developing DPI formulations of poorly water-soluble ITZ.

Endotracheal Aerosolization Device for Laboratory Investigation of Pulmonary Delivery of Nanoparticle Suspensions: In Vitro and in Vivo Validation

The objective of this study was to perform the in vitro and in vivo validation of an endotracheal aerosolization (ETA) device (HRH MAG-4, HM). Solid lipid nanoparticle suspension (SLNS) formulations with particle sizes of approximately 120, 240, 360, and 480 nm were selected as model nanoparticle suspensions for the validation. The emission rate (ER) of the in vitro aerosolization and the influence of aerosolization on the physicochemical properties were investigated. A high ER of up to 90% was obtained, and no significant alterations in physicochemical properties were observed after the aerosolization. The pulmonary deposition of model drug budesonide in Sprague-Dawley rats was determined to be approximately 80%, which was satisfactory for pulmonary delivery. Additionally, a fluorescent probe with aggregation-caused quenching property was encapsulated in SLNS formulations for in vivo bioimaging, after excluding the effect of aerosolization on its fluorescence spectrum. It was verified that SLNS formulations were deposited in the lung region. The results demonstrated the feasibility and reliability of the HM device for ETA in laboratory investigation.

Formation Mechanism and In Vitro Evaluation of Risperidone-Containing PLGA Microspheres Fabricated by Ultrafine Particle Processing System

Ultrafine particle processing system (UPPS) was developed previously by our group to provide a new solution to microsphere fabrication. The UPPS was supposed to possess many featured advantages, but the microsphere formation mechanism during UPPS processing was still unknown. The objective of this study was to perform the formation mechanism investigation and in vitro evaluation on risperidone-containing poly(d, l-lactic-co-glycolic acid) microspheres (RIS-PLGA MS) fabricated by UPPS. Evaporation profile and viscosity of the PLGA-containing solutions were considered as the critical factors for the microsphere formation mechanism and were determined in present study. The formation mechanism of RIS-PLGA MS was put forward by semiquantitative analysis on the basis of the evaporation profile, viscosity, and scanning electron microscopy results. It was established that the evaporation profile and viscosity would have an impact on the evaporation velocity and PLGA molecular diffusion velocity during solidification process, resulting in different appearance of the microspheres. Furthermore, comprehensive in vitro evaluations of RIS-PLGA MS were conducted, including particle size distribution, micromeritics, morphology, drug loading, encapsulation efficiency, residual organic solvent, syringeability, and in vitro release behavior. The results revealed that RIS-PLGA MS was a promising candidate for intramuscular administration, and meanwhile UPPS was a qualified technology for microsphere production.

Major difference in particle size, minor difference in release profile: a case study of solid lipid nanoparticles

Solid lipid nanoparticles (SLN) have been widely used in a variety of drug delivery routes, which have the outstanding advantage of controlled drug release. The release of SLN is dominated by many factors, among which the particle size of SLN is a critical one. The aim of this project was to explore the relationship between drug release profile and particle size of SLN. SLN were synthesized via the hot high-pressure homogenization (HPH) method, budesonide (BUD) was used as the model drug, and BUD-SLN1-BUD-SLN4 with increasing particle size was obtained, i.e. 120, 240, 360, and 480 nm. The prepared SLN has good encapsulation efficiency, drug loading capacity, and stability. In vitro release behavior studies showed that the cumulative release of BUD-SLN in Tris-Maleate (Tris-M) media was negligible, while that in Tris-M plus pancreatin media or Tris-M-ethanol media obeyed Ritger-Peppas model or first-order kinetic model, respectively. Noticeably, the release behavior of SLN was to some extent related to the average particle size of SLN, but the correlation was insignificant when the intersection degree of particle size distribution was great. This study provides a new idea for the understanding of in vitro release of SLN and has a certain referencing value for the research and development of novel nanomedicines.

Unraveling the publication trends in inhalable nano-systems

Nano-systems (size range: 1 ~ 1000 nm) have been widely investigated as pulmonary drug delivery carriers, and the safety of inhaled nano-systems has aroused general interests. In this work, bibliometric analysis was performed to describe the current situation of related literature, figure out the revolutionary trends, and eventually forecast the possible future directions. The relevant articles and reviews from 2001 to 2020 were retrieved from the Web of Science Core Collection. The documents were processed by Clarivate Analytic associated with Web of Science database, Statistical Analysis Toolkit for Informetric, bibliometric online platform and VOSviewer, and the data were visualized. The bibliometric overview of the literature was described, citation analysis was performed, and research hotspots were showcased. The bibliometric analysis of 3362 documents of interest indicated that most of the relevant source titles were in the fields of toxicology, pharmacy, and materials science. The three research hotspots were the biological process of inhalable nano-systems in vivo, the manufacture of inhalable nano-systems, and the impact of nano-systems on human health in the environment. Toxicity and safety have always been the keywords. The USA was the major contributing country, and international collaboration and co-authorship were common phenomena. The general situation and development trend of literature of inhalable nano-systems were summarized. It was anticipated that bibliometrics analysis could provide new ideas for the future research of inhalable nano-systems.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11051-021-05384-1.

Bibliometric landscape of the researches on protein corona of nanoparticles

Unclear biological fate hampers the clinical translation of nanoparticles for biomedical uses. In recent years, it is documented that the formation of protein corona upon nanoparticles is a critical factor leading to the ambiguous biological fate. Efforts have been made to explore the protein corona forming behaviors on nanoparticles, and rearrangement of the relevant studies will help to understand the current trend of such a topic. In this work, the publications about protein corona of nanoparticles in Science Citation Index Expanded database of Web of Science from 2007 to 2020 (1417 in total) were analyzed in detail, and the bibliometrics landscape of them was showcased. The basic bibliometrics characteristics were summarized to provide an overall understanding. Citation analysis was performed to scrutinize the peer interests of these papers. The research hotspots in the field were evaluated, based on which some feasible topics for future studies were proposed. In general, the results demonstrated that protein corona of nanoparticles was a prospective research area, and had attracted global research interests. It was believed that this work could comprehensively highlight the bibliometrics landscape, inspire further exploitation on protein corona of nanoparticles, and ultimately promote the clinical translation of nanoparticles.

Progress on Pharmaceutical Sciences/Pharmacy Postgraduate Education: a Bibliometric Perspective

OBJECTIVE

The study quantitatively investigated the related research progress in pharmaceutical sciences/pharmacy education from a bibliometric angle and provided feasible suggestions to facilitate the development of pharmaceutical sciences/pharmacy postgraduate education.

METHODS

Bibliometric analysis was conducted using the database of Web of Science Core Collection. The literature published in 1985-2021 was screened and selected. The overall profile description, citation analysis, and research hotspot mining were performed using the citation report of Clarivate Analytics, bibliometrics online platform, and VOSviewer software. The bibliometric results and profiles were plotted and illustrated.

RESULTS

The bibliometric analysis of 485 papers of interest showed that the research frontier was continuously expanding; especially the institutions from the USA were the main contributors. The numbers of citing papers have been ascending, and a considerable part of citations were from the areas other than the education research. Mining results showed that the in-school and residency education of pharmacy postgraduates was a research hotspot, as well as interprofessional training and new education styles for Coronavirus Disease 2019 (COVID-19) therapy were the emerging trends in the field.

CONCLUSION

Through the analysis of the studies, it was found that encouraging relevant research programs, establishing financial supports, and launching specified publication sources could be helpful to boost the development of pharmaceutical sciences/pharmacy postgraduate education. Besides, the results suggested that this was a less discussed topic and was worthy for the investigators to pay more attention to such an issue.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12247-021-09611-z.

Low Drug Loading Hampers the Clinical Translation of Peptide Drugs-Containing Metered-Dose Inhalers

Peptide-based drugs have attracted extensive attention from the medical and pharmaceutical industry because of their relatively high safety and efficacy. However, most of the peptide drugs approved are administrated by injection, which can easily cause poor patient compliance. In this circumstance, pulmonary administration as an alternative to injection administration can not only avoid the above issue but also accelerate the absorption rate of peptide drugs and improve bioavailability. Among the pulmonary delivery systems available on the market, metered-dose inhalers (MDIs) have emerged as appealing candidates for pulmonary delivery systems with clinical translational value, owing to their many merits, including portable, easy-to-operate, and cost-effective properties. Nevertheless, the industrialization of peptide drugs-containing MDIs encounters a bottleneck of low drug loading, owing to the incompatibility between the propellant and the peptide drugs, which cannot be effectively overcome by the current carrier particle encapsulation strategy. Herein, we put forward the following strategies: (1) To screen amphiphilic materials with high surface activity and strong interaction with peptide drugs; (2) To construct a chemical connection between peptide drugs and amphiphilic substances; (3) To optimize the cosolvent for dispersing peptide drugs. We suppose these strategies have the potential to defeat the bottleneck problem and provide a new idea for the industrialization of peptide drugs-containing MDIs.

Explicating the publication paradigm by bibliometric approaches: A case of interplay between nanoscience and ferroptosis

BACKGROUND

Ferroptosis has been widely investigated as an emerging drug target, while its combination with nanoscience provides bourgeoning application prospects. The development of ferroptosis regulating nanomedicines have attracted worldwide attentions in recent years. It would be meaningful to describe the relevant publication paradigm.

METHODS

Herein, a bibliometric analysis was performed using the database of Web of Science Core Collection to clarify the publication paradigm. The development of related publications in the last 6 years was described, and the revolutionary trends were figured out. Ultimately, the possible future exploration directions were proposed.

RESULTS

The bibliometric analysis of 327 documents of interest indicated that the main research focus was in multiple fields including Materials science, Science & technology, Chemistry, and Pharmacology & pharmacy. With widely cooperation and strong funding, the researchers from Chinese organizations contributed most of publications, followed with United States and Australia. Cocitation analysis revealed that several original papers reported the key molecular mechanisms of ferroptosis were considered as the foundation for subsequent studies, and some nanomedicines-related documents were taken as examples and discussed. Mining results showed that the mechanism evaluation of ferroptosis regulation therapy for cancer treatment was the hotspot. Then, several possible future explorations of ferroptosis-related nanoscience were presented and discussed.

CONCLUSIONS

The bibliometric profile of nanoscience-ferroptosis research was analyzed in detail. We believe that the bibliometric analysis could act as a robust method for explicating the publication paradigm as a certain field.

Research on nanosciences involvement in pharmaceutical education should be reinforced

Inclusion of nanoscience in pharmaceutical education should be reinforced, in order to match the demand of current pharmaceutical talent cultivation.