Improved Activity of Rifampicin Against Biofilms of Staphylococcus aureus by Multicomponent Complexation

Influence of degree of substitution on the hydroxypropyl-β-cyclodextrin complexation with rifampicin in water solution: a molecular simulation

CONTEXT

Hydroxypropyl-β-cyclodextrin (HPβCD) is one of the derivatized cyclodextrins most widely used as an excipient in the pharmaceutical industry, for its capacity to improve certain drugs properties. Different configurations of HPβCD are possible depending on the number and location of the 2-hydroxypropyl groups substituted on the glucose rings. Rifampicin has become the most commonly clinically used antibiotic against tuberculosis in recent years, despite its low solubility and variable bioavailability. Different techniques and materials have been proposed to enhance the properties of rifampicin: cyclodextrin complexation is one of them. The van der Waals term was the main contribution to the interaction energy, which then decisively conditioned the complex configurations. The size of rifampicin did not allow the whole molecule to fit into the host. Moreover, interaction energy was much greater when the guest was located near each rim of HPβCD, where rifampicin was partially included in the cavity and formed inclusion complexes. The piperazine tail of rifampicin was included inside the host in minimum energy structures and the guest was situated near the primary rim of HPβCD in most cases, although the complex configurations depended on the degree of substitution.

METHODS

A molecular mechanics simulation based on the GROMOS 53A6 force field was applied in this work to study the inclusion complexes formed by twelve configurations of HPβCD, with different degrees of substitution and rifampicin in water solution. We determined the penetration potential, the complex structures with minimum energies, the possibility of forming inclusion complexes other than those of minimum energies and potential energy surfaces.

Cyclodextrin inclusion complexes improving antibacterial drug profiles: an update systematic review

Aim: The study aimed to review experimental models using cyclodextrins to improve antibacterial drugs' physicochemical characteristics and biological activities. Methods: The following terms and their combinations were used: cyclodextrins and antibacterial agents in title or abstract, and the total study search was conducted over a period up to October 2022. The review was carried out using PubMed, Scopus and Embase databases. A total of 1580 studies were identified, of which 27 articles were selected for discussion in this review. Results: The biological results revealed that the antibacterial effect of the inclusion complexes was extensively improved. Cyclodextrins can enhance the therapeutic effects of antibiotics already existing on the market, natural products and synthetic molecules. Conclusion: Overall, CDs as drug-delivery vehicles have been shown to improve antibiotics solubility, stability, and bioavailability, leading to enhanced antibacterial activity.

Dual antituberculosis drugs-loaded gelatin hydrogel bioimplant for treating spinal tuberculosis

Spinal tuberculosis (TB) represents around 1% of the recorded TB with a high mortality rate due to neurological complications and kyphosis. The current work aimed to develop a bioimplant scaffold to treat spinal TB disease. The scaffold is composed of a biocompatible semi-interpenetrating (semi-IPN) gelatin-based hydrogel incorporating mesoporous silica nanoparticles (MPS-NPs) loaded with rifampicin (RIF) and levofloxacin (LEV) to treat TB. The elastic modulus of the hydrogel was 7.18 ± 0.78 MPa. Minimum inhibitory concentrations (MIC) value against Mycobacterium bovis for LEV-loaded and RIF-loaded MPS-NPs were 6.50 and 1.33 µm/ml, respectively.Sequential release of drugs was observed after 15 days. Loading of the MPS-NPs in the hydrogel matrix governed the amount of released drugs by prolonging the period of release up to 60 days. WST-1 test confirmed the biocompatibility and safety of the developed vertebral hydrogel bioimplant. Histological and immunohistochemistry micrographs showed the progress in healing process with the bioimplant. Besides, loading of LEV and RIF in the implants declined the presence of the giant macrophages clusters as compared to control groups. All the obtained results support the potential use of the developed vertebral hydrogel bioimplant as a scaffold with good mechanical and biocompatible properties along with a good ability to eradicate the TB pathogen.

Development and Characterization of Pharmaceutical Systems Containing Rifampicin

Rifampicin is a potent antimicrobial drug with some suboptimal properties, such as poor stability, low solubility, and variable bioavailability. Therefore, in the current study, a multicomponent complex between rifampicin, γ-cyclodextrin, and arginine was prepared with the aim of improving drug properties. Solubility was evaluated by phase-solubility studies. The mechanism of interaction was established through proton nuclear magnetic resonance spectroscopy and molecular modeling. Physicochemical characterization was investigated using Fourier transform-infrared spectroscopy, powder X-ray diffraction, and scanning electron microscopy. The dissolution properties, antimicrobial activity (antibacterial, antibiofilm, and antileishmanial), and stability of the different samples were studied. The results obtained in this investigation demonstrate that multicomponent complexes can improve the water solubility and dissolution rate of rifampicin, as well as its antibacterial and antileishmanial action, and present suitable stability. In conclusion, rifampicin complexed with γ-cyclodextrin and arginine is an attractive approach for developing pharmaceutical dosage forms of rifampicin with increased antimicrobial activities.

Amino acids and its pharmaceutical applications: A mini review

Amino acids are natural compounds that can be safely used in pharmaceutical applications. Considering the great interest in the amino acids used in the pharmaceutical industry, this article presents an overview of investigations reported in recent years. In this regard, the first sections begin with an introductory description of the properties, classification and safety of amino acids, while in the other sections the most common methods for the preparation of amino acids formulations and their application on solubilization, permeation and stabilization of several active pharmaceutical ingredients are described. Furthermore, available data about the multicomponent systems approach is included. Lastly, the impact of amino acids formulations on therapeutic efficacy is explored. The advantages illustrated suggest that amino acids are capable of improving the biopharmaceutical properties of drugs.

Cyclodextrin Multicomponent Complexes: Pharmaceutical Applications

Cyclodextrins (CDs) are naturally available water-soluble cyclic oligosaccharides widely used as carriers in the pharmaceutical industry for their ability to modulate several properties of drugs through the formation of drug-CD complexes. The addition of an auxiliary substance when forming multicomponent complexes is an adequate strategy to enhance complexation efficiency and to facilitate the therapeutic applicability of different drugs. This review discusses multicomponent complexation using amino acids; organic acids and bases; and water-soluble polymers as auxiliary excipients. Special attention is given to improved properties by including information on the solubility, dissolution, permeation, stability and bioavailability of several relevant drugs. In addition, the use of multicomponent CD complexes to enhance therapeutic drug effects is summarized.

Faster Detection of Staphylococcus aureus in Milk and Milk Powder by Flow Cytometry

A flow cytometry (FCM)-based method was developed for the faster detection of Staphylococcus aureus in milk and milk powder. Viable S. aureus cells were recognized by highly selective, fluorescently labeled antibodies and Propidium Iodide, and then analyzed by FCM. Using a 5-h pre-enrichment period, the method could detect low numbers of S. aureus cells in 6 h, with a limit of detection of 7.50 cells/mL in milk and 8.30 cells/g in milk powder. The established method was compared with the plate-based method using 75 ultra-high-temperature-treated milk samples, 25 pasteurized milk samples, 66 raw milk samples, and 123 milk powder samples. The two methods yielded similar results for the detection of the pathogen in all sample types. The FCM-based method allows effective and faster monitoring of S. aureus contamination and can be applied to the rapid detection of microorganisms in milk and dairy products.