Special Issue "Nanocrystal Technology & BCS Class II and Class IV Drug Delivery: Experimental Advances and Clinical Applications"

A special issue of Crystals (ISSN 2073-4352). This special issue belongs to the section "Biomolecular Crystals".

Deadline for manuscript submissions: closed (30 June 2023) | Viewed by 2206

Special Issue Editors

Departments of Nanomedicine and Translational Medicine, Fluorotronics-CIC, San Diego, CA 92037, USA
Interests: nanomaterials; nanomedicine; photocatalysis; bioremediation; sustainability; green chemistry; nanotoxicity; environmental engineering; pharmaceutics; nanotheranostics; nanosensing
Special Issues, Collections and Topics in MDPI journals
Vaasudhara College of Pharmacy (Rajiv Gandhi University of Health Sciences), Sante Circle, Chintamani Road, Hoskote 562114 Bangalore, Karnataka, India
Interests: thermal properties; pharmaceutical formulation; formulation development of pharmaceuticals; pharmaceutical research and development; pharmaceutics and pharmaceutical technology; drug formulation; controlled drug delivery; pharmaceutical development; bioavailability; pharmaceutical analysis

Special Issue Information

Dear Colleagues,

Over the last ten years, the number of poorly soluble drugs (biopharmaceutical specification (BCS) class II and class IV) has steadily increased. Progress in high-throughput screening (HTS) methods has revealed an even greater amount of newly discovered drugs that have a poor water solubility, and poor solubility in water correlates with poor bioavailability. If there is no method for improving drug solubility, it cannot be absorbed from the gastrointestinal tract (GIT) into the bloodstream and reach the site of action. The transfer of materials in the nanodimension affects their physical properties, which are used in the development of  new and innovative pharmaceutical formulation principles for poorly soluble drugs. Drug nanocrystals (i.e., nanosized crystal of parent drug with dimension < 1 μm and exempt of a carrier) represent a great example of nanonization for oral and intravenous (IV) bioavailability enhancement. Due to their success and increasing attention, the first NC products are already in the market. Indeed, conventional drug delivery systems (DDS) solubilize certain poorly soluble drugs but are limited to drugs with certain chemical–physical properties (e.g., solubility in certain organic media, molecular size, or conformation). Additionally, the use of surfactants or cosolvents in traditional DDS may increase side effects due to their relative toxicity. An esterification method can be used to simultaneously increase drug solubility and permeability (BCS drugs class IV), but little consideration is given to the biological effect and/or toxicity of the structural modifications; therefore, derivatives are rarely tested for toxicity, potency, tissue distribution, or elimination. Additionally, the micronization of drug powders to sizes between 1 and 10 μm to increase their surface area, and thus the dissolution velocity, is not sufficient for overcoming bioavailability problems of many very poorly soluble drugs of BCS class II.

Nowadays, drug NCs are increasingly studied as a promising approach owing to many reasons including the (i) increasing number of poor-soluble drugs in drug development process, (ii) pharmacoeconomic value, (iii) easy production, (iv) safe composition. Soon, it could be expected that the drug NCs doped with certain surface proteins will be prepared for targeting a particular tissue (e.g., skin) or cell (e.g., tumor cell). This Special Issue aims to highlight the current state-of-the art of advanced nanocrystal drugs with a special emphasis on BCS class II and class IV. Researchers, industrials, biomedical engineers, technologists, chemists, pharmacists, toxicologists, and healthcare professionals who specialize in nanomedicine, nanotechnology, pharmaceutical formulation, and translational medicine are invited to share their knowledge by contributing original basic, applied, and clinical research articles. Review articles are also encouraged. The manuscripts must be of a high-quality and emphasize the impact of advanced nanocrystal drugs. In vitro, ex vivo, and in vivo assays should be performed using advanced techniques and methods. Innovation using tunable functionalized NCs tested in various mammalian cell lines/types, animal models and a clinical setting will particularly be appreciated:


Potential topics may include, but are not limited to, the following:

  • Preparation of NCs (bottom-up approaches, such as precipitation, spray drying, and lyophilization; top-down approaches such as milling methods and high-pressure homogenization; combination approach; stabilization (e.g., with Poloxamer 188);
  • Properties of NCs (solubility and saturation solubility enhancement, dissolution and dissolution velocity, permeation, bioavailability, adhesiveness to surface/cell membrane);
  • Characterization of NCs (PS, ZP, PDI, XRD, DSC, SEM, TEM, drug content analysis, release behavior studies);
  • NCs of BCS class II and BCS class IV;
  • Solid or Suspension NCs;
  • Topical applications of NCs;
  • Tunable functionalization of NCs;
  • NCs products in market;
  • Clinical trials involving NCs (e.g., Paclitaxel, Ciprofloxacin, Rapamycin)

Prof. Dr. Farid Menaa
Dr. Jamal Moideen Muthu Mohamed
Guest Editors

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  • preparation of NCs NCs of BCS class II and BCS class IV
  • properties of NCs
  • NCs of BCS class II and BCS class IV
  • characterizations of NCs
  • solid or suspension NCs
  • topical applications of NCs
  • NCs products in market
  • clinical trials involving NCs

Published Papers (1 paper)

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Preparation of Memantine-Loaded Chitosan Nanocrystals: In Vitro and Ex Vivo Toxicity Analysis
Crystals 2023, 13(1), 21; https://doi.org/10.3390/cryst13010021 - 23 Dec 2022
Cited by 1 | Viewed by 1734
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with unmet medical need, and is the leading cause of age-related dementia affecting millions of people worldwide. This work aims at developing small, high-drug loading capacity (DL) and -entrapment efficiency (EE) memantine hydrochloride (MEM)/chitosan nanocrystals [...] Read more.
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with unmet medical need, and is the leading cause of age-related dementia affecting millions of people worldwide. This work aims at developing small, high-drug loading capacity (DL) and -entrapment efficiency (EE) memantine hydrochloride (MEM)/chitosan nanocrystals (CS-NCs) to treat moderate to severe dementia associated with AD. MEM-loaded chitosan nanocrystals (MEM/CS-NCs, further abbreviated as MEM-NCs) were prepared by the ionic gelation method. Different formulations were prepared by varying the concentrations of CS and sodium tripolyphosphate (STPP). The prepared MEM-NCs formulations (n = 8) were evaluated for their particle size (PS), polydispersibility index (PDI), zeta potential (ZP), DL, EE and characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Furthermore, in vitro (i.e., release behavior, cytotoxicity) and ex vivo studies (i.e., histopathology) studies were carried out. The results show that the DL was over 92% and the EE was higher than 73%, while the particles were relatively small with nanometric PS (152.63 ± 12.95 to 310.23 ± 10.49 nm), uniform with acceptable PDI (0.336 ± 0.05 to 0.534 ± 0.02), and stable with positive ZP (23.8 ± 0.4 mV to 54.0 ± 0.5 mV). The optimal formulation (MEM-NC3) was selected mainly based on the PS (152.63 ± 12.95 nm), DL (98.44 ± 3.31%), and EE (78.7 ± 3.11%). Interestingly, it does not elicit any cytotoxic and tissue damage when examining at goat nasal mucosa. The selected formulation was subjected to surface morphological studies such as transmission electron microscopy (TEM), which revealed that the NCs were spherical in shape and small (100 nm). Interestingly, the selected formulation was able to sustain the drug release for up to 24 h with an initial burst release (86.51 %). We conclude that the prepared MEM-NCs represent a promising drug formulation for further in vivo studies (in animal models and in a clinical setting) to prevent and treat AD. Full article
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