Oral route maintains its predominance among the ones used for drug delivery, especially when medicines are self-administered. If the dosage form is solid, therapy gains in dose precision and drug stability. Yet, some active pharmaceutical substances do not present the required solubility, permeability or release profile for incorporation into traditional matrices. The combination of nanostructured drugs (NP) with these matrices is a new and little-explored alternative, which could bring several benefits. Therefore, this review focused on combined delivery systems based on nanostructures to administer drugs by the oral cavity, intended for buccal, sublingual, gastric or intestinal absorption. We analyzed published NP-in-matrix systems and compared main formulation characteristics, pharmacokinetics, release profiles and physicochemical stability improvements. The reported formulations are mainly semisolid or solid polymers, with polymeric or lipid nanoparticles and one active pharmaceutical ingredient. Regarding drug specifics, most of them are poorly permeable or greatly metabolized. The few studies with pharmacokinetics showed increased drug bioavailability and, sometimes, a controlled release rate. From our knowledge, the gathered data make up the first focused review of these trendy systems, which we believe will help to gain scientific deepness and future advancements in the field.

Chloroquine diphosphate (CQ) is a hydrophilic drug with low entrapment efficiency in hydrophobic nanoparticles (NP). Herpes simplex virus type 1 (HSV-1) is an enveloped double-stranded DNA virus worldwide known as a common human pathogen. This study aims to develop chloroquine-loaded poly(lactic acid) (PLA) nanoparticles (CQ-NP) to improve the chloroquine anti- HSV-1 efficacy. CQ-NP were successfully prepared using a modified emulsification-solvent evaporation method. Physicochemical properties of the NP were monitored using dynamic light scattering, atomic force microscopy, drug loading efficiency, and drug release studies. Spherical nanoparticles were produced with modal diameter of <300 nm, zeta potential of −20 mv and encapsulation efficiency of 64.1%. In vitro assays of CQ-NP performed in Vero E6 cells, using the MTT-assay, revealed different cytotoxicity levels. Blank nanoparticles (B-NP) were biocompatible. Finally, the antiviral activity tested by the plaque reduction assay revealed greater efficacy for CQ-NP compared to CQ at concentrations equal to or lower than 20 µg mL⁻¹ (p < 0.001). On the other hand, the B-NP had no antiviral activity. The CQ-NP has shown feasible properties and great potential to improve the antiviral activity of drugs.

Doxycycline (DX) is a well-established and broad-spectrum antimicrobial drug. However, DX has drawbacks, such as physicochemical instability in aqueous media and bacterial resistance. The inclusion of drugs in cyclodextrin complexes and their loading into nanocarriers can overcome these limitations. Thus, we studied the DX/sulfobutylether-β-CD (SBE-β-CD) inclusion complex for the first time and used it to reticulate chitosan. The resulting particles were evaluated by their physicochemical characteristics and antibacterial activity. DX/SBE-β-CD complexes were characterized by nuclear magnetic resonance, infrared spectroscopy, thermal analysis, X-ray diffraction, and scanning electron microscopy (SEM), whereas DX-loaded nanoparticles were characterized by dynamic light scattering, SEM, and drug content. The partial inclusion of the DX molecule in CD happened in a 1:1 proportion and brought increased stability to solid DX upon thermal degradation. Chitosan-complex nanoparticles measured approximately 200 nm, with a narrow polydispersity and particles with sufficient drug encapsulation for microbiological studies. Both formulations preserved the antimicrobial activity of DX against Staphylococcus aureus, whereas DX/SBE-β-CD inclusion complexes were also active against Klebsiella pneumoniae, indicating the potential use of these formulations as drug delivery systems to treat local infections.

Snakebite envenoming represents a worldwide public health issue. Suitable technologies have been investigated for encapsulated recombinant or native proteins capable of inducing an effective and long-lasting adaptive immune response. Nanoparticles are colloidal dispersions that have been used as drug delivery systems for bioactive biological compounds. Venom-loaded nanoparticles modulate the protein release and activate the immune response to produce specific antibodies. In this study, biocompatible cationic nanoparticles with Bothrops jararaca venom were prepared to be used as a novel immunoadjuvant that shows a similar or improved immune response in antibody production when compared to a conventional immunoadjuvant (aluminum hydroxide). We prepared stable, small-sized and spherical particles with high Bothrops jararaca venom protein association efficiency. The high protein loading efficiency, electrophoresis, and zeta potential results demonstrated that Bothrops jararaca venom is adsorbed on the particle surface, which remained as a stable colloidal dispersion over 6 weeks. The slow protein release occurred and followed parabolic diffusion release kinetics. The in vivo studies demonstrated that venom-loaded nanoparticles were able to produce an immune response similar to that of aluminum hydroxide. The cationic nanoparticles (CNp) as carriers of bioactive molecules, were successfully developed and demonstrated to be a promising immunoadjuvant.

In recent years, bacterial infections have become a major global concern, causing significant morbidity and mortality. Unfortunately, the development and commercialization of new antibacterial drugs have been slow, while pathogens continue to rapidly adapt and evolve. To address this challenge, nanotechnology offers a promising strategy by protecting, targeting, and releasing active compounds to fight against these emerging strains. The aim of this study was to explore the antibacterial potential of nanoemulsions (NEs), as reported in the scientific literature. A literature review was carried out utilizing the keywords “nanoemulsion”, “antibiotic activity”, “antibacterial activity”, and “antimicrobial activity”. All of the scientific articles that were related to the area of health and published in the last 5 years were included. All of the studies indicated that oil-based NEs with inherent antibacterial activity, even without the presence of drugs, had superior action against strains compared to non-emulsified oil, as well as other systems incorporating drugs or actives. Although the results are promising, further investigations and testing of formulations against resistant bacterial strains are necessary. This review aims to provide valuable insights for researchers and contribute to future advancements in this field.

Doxycycline (DX) is a well-established and broad-spectrum antimicrobial drug. However, DX has drawbacks, such as physicochemical instability in aqueous media and bacterial resistance. It is known that the inclusion of drugs in cyclodextrin complexes and their loading in nanocarriers can overcome these limitations. Thus, we developed DX/sulfobutylether-β-CD (SBE-β-CD) inclusion complexes and DX-loaded nanoparticles, evaluating their physicochemical characteristics and antibacterial activity. DX/SBE-β-CD complexes were characterized by nuclear magnetic resonance, infrared spectroscopy, thermal analysis, X-ray diffraction and scanning electron microscopy (SEM), whereas DX-loaded nanoparticles were characterized by dynamic light scattering, SEM and drug content. Complexes and chitosan nanoparticles presented approximately 200 nm size, narrow polydispersity and particles with sufficient drug encapsulation (25%) for microbiological studies. Both formulations showed antimicrobial activity against Staphylococcus aureus, whereas DX/SBE-β-CD inclusion complexes were also active against Klebsiella pneumoniae , indicating the potential use of these formulations as drug delivery systems to treat local infections.