Research paperCapreomycin supergenerics for pulmonary tuberculosis treatment: Preparation, in vitro, and in vivo characterization
Graphical abstract
Introduction
Tuberculosis (TB) is an infectious bacterial disease of which Mycobacterium tuberculosis is recognized as the etiological agent. Even though the etiology was elucidated more than a century ago, TB is still one of the most serious diseases caused by a single pathogen [1], [2]. In fact, the World Health Organization (WHO) reported, in 2010, 1.4 million deaths, 8.8 million new and relapse cases, and 5.7 million new and recurrent TB patients treated [3].
The failure of the disease control is surely due to TB epidemiology. In fact, even though all countries are affected by TB, most cases (∼85%) are registered in Africa (∼30%) and in Asia (∼55%), where social and health conditions are not optimal, and the access to medicines is limited or completely lacking. In addition, TB chemotherapy features can be also considered responsible for the lack of disease control. At the moment, the recommended therapies, known as DOTS (directly observed treatment, short-course) and DOTS-Plus, consist of four co-administered drugs (6-month therapy), with the addition of second line antitubercular drugs (therapy duration up to 24 months) in the case of multi-drug-resistant (MDR) strains [3]. These long-term multi-drug therapies are characterized by low patient compliance and high rates of discontinuation responsible for the insurgence of resistant strains, known as MDR and extensive drug-resistant (XDR) strains [4].
In this scenario, the scientific community is attempting to solve this complex problem adopting different strategies, such as the development of new and more effective antitubercular drugs [5], [6] and vaccines [7], [8], the use of new drug cocktails [9], and the reformulation of currently used drugs in more effective and less toxic forms [10], [11].
The latter strategy is focused mainly on the production of drug inhalable powders and/or on antitubercular embedding in micrometric and/or nanometric particulate systems, able to target the site of infection. Considering that the site of primary infection is the lungs, and about 75% of the TB cases are referred to pulmonary tuberculosis; a reliable improvement of the therapy could be achieved by using inhalation as route of administration [12]. The combination of inhalation therapy, with the use of adequate (insoluble) particulate systems, provides the possibility to target alveolar macrophages [13], the M. tuberculosis host cells [14], [15].
Second line antitubercular drugs are the most interesting compounds to formulate in novel drug delivery systems due to their high toxicity and low incidence of resistance. In this respect, capreomycin sulfate, a nonapeptide included in the injectable second line antitubercular drugs [3], has been extensively evaluated for inhalation therapy both in the form of respirable powder [16], [17], [18] or encapsulated in particulate carriers [19], [20]. Capreomycin sulfate respirable powder has been evaluated in a phase I clinical trial with promising results [21].
The aim of this study was to develop a simple and scalable production methodology for capreomycin hydrophobic ion-pairs (HIP), in order to obtain low-soluble inhalable powders to use as supergenerics. To reduce capreomycin systemic absorption and maximize intracellular drug concentration, efforts were made to decrease as much as possible the non-ion-paired capreomycin content in the formulations. The rational of using fatty acid capreomycin salts as supergenerics is twofolds. Fatty acid counterions, by conferring lipophilicity to the salts, allow the production of insoluble particles able to be taken up by infected macrophages. Once released in the lysosomal acidic environment, fatty acids can reactivate or sensibilize dormant bacteria. In fact, different lipids have been found involved in the formation and reactivation of Mycobacterium smegmatis “nonculturable” cells and oleic acid, in concentration between 0.05 and 3 μg/mL, showed the most efficient reactivating effect [22]. It is speculated that capreomycin HIPs, in particular CO, could be used to improve TB therapy outcomes using a “shock and kill” strategy. This novel approach has been recently proposed and successfully tested in vitro for HIV-1 eradication [23], [24]. In the specific case of TB, dormant bacteria are considered responsible for TB reactivation, and this strategy could turn out to be very interesting by considering the difficulties encountered in eradicating dormant mycobacteria [9]. The antimicrobial activity of the different HIPs was assessed in vitro on M. tuberculosis, while in vivo acute toxicity has been evaluated using chick embryo chorioallantoic membrane (CAM) assay.
Section snippets
Materials
Capreomycin sulfate (CS), sodium oleate (SO), and sodium linoleate (SL) were purchased from Sigma-Aldrich Chemical (Milan, Italy), while sodium linolenate (SLn) was obtained from Nu-Chek, Inc. (Elysian, MN, USA). All other chemicals and reagents were of the highest purity grade commercially available.
Hydrophobic ion-pair preparation
Capreomycin oleate (CO) and linoleate (CL) were prepared using ethanol–water mixtures as solvent, while capreomycin linolenate (CLn) was prepared in a mixture of acetone and water. Briefly, CS and
HIP powder preparation and characterization
In a previous paper, CO was prepared from aqueous solutions and successively processed by high pressure homogenization to reduce particle dimensions [34]. In this work, the preparation method was improved, and two additional HIP powders were prepared. Instead of water, a mixture of ethanol and water was used to prepare CO and CL, while acetone and water were used to obtain CLn. The ratio between the two solvents has been adjusted to allow single component complete dissolution and guarantying
Conclusion
Three different hydrophobic capreomycin salts were successfully produced using mini spray-dryer, while CO was also efficiently obtained using nano spray-dryer. CO, characterized by particle dimensions potentially suitable for inhalation, high ion-paired capreomycin content, and antimycobacterial activity comparable to CS, was the most promising to produce a supergeneric. Comparing the toxicity profile of capreomycin oleate and sulfate salts on chicken embryo chorioallantoic membrane, oleate
References (46)
- et al.
Systems biology approaches to new vaccine development
Curr. Opin. Immunol.
(2011) - et al.
Inhaled drug therapy for treatment of tuberculosis
Tuberculosis
(2011) - et al.
Insulin-loaded PLGA/cyclodextrin large porous particles with improved aerosolization properties: in vivo deposition and hypoglycaemic activity after delivery to rat lungs
J. Control. Release
(2009) - et al.
Preparation of large porous biodegradable microspheres by using a simple double-emulsion method for capreomycin sulfate pulmonary delivery
Int. J. Pharm.
(2007) - et al.
Simple and scalable method for peptide inhalable powder production
Eur. J. Pharm. Sci.
(2010) - et al.
Nanoparticles by spray drying using innovative new technology: the Büchi Nano Spray Dryer B-90
J. Control. Release
(2010) - et al.
Mechanistic models facilitate efficient development of leucine containing microparticles for pulmonary drug delivery
Int. J. Pharm.
(2011) - et al.
UV spectroscopy and reverse-phase HPLC as novel methods to determine capreomycin of liposomal formulations
J. Pharm. Biomed. Anal.
(2004) - et al.
The chick embryo and its chorioallantoic membrane (CAM) for the in vivo evaluation of drug delivery systems
Adv. Drug Deliv. Rev.
(2007) - et al.
Development of liposomal capreomycin sulfate formulations: effects of formulation variables on peptide encapsulation
Int. J. Pharm.
(2006)
New insights into respirable protein powder preparation using a nano spray dryer
Int. J. Pharm.
Effects of pulmonary surfactant system on rifampicin release from rifampicin loaded PLGA microspheres
Colloids Surf. B: Biointerfaces
The aetiology of tuberculosis, Dr. Robert Koch
Am. Rev. Tuberc.
125 years after Robert Koch’s discovery of the tubercle bacillus: the new XDR-TB threat. Is “science’’ enough to tackle the epidemic?
Eur. Respir. J.
Management of multidrug-resistant tuberculosis: update
Respirology
New drugs and new regimens for the treatment of tuberculosis: review of the drug development pipeline and implications for national programmes
Curr. Opin. Pulm. Med.
Current status and research strategies in tuberculosis drug development
J. Med. Chem.
Immunization by a bacterial aerosol
Proc. Natl. Acad. Sci. USA
Activity of drug combinations against dormant Mycobacterium tuberculosis
Antimicrob. Agents Chemother.
Fighting tuberculosis: old drugs, new formulations
Expert Opin. Drug Deliv.
Partial biodistribution and pharmacokinetics of isoniazid and rifabutin following pulmonary delivery of inhalable microparticles to rhesus macaques
Mol. Pharmaceut.
Large porous particles for pulmonary drug delivery
Science
Cited by (45)
Antibiotics modified by hydrophobic ion-pairing – A solution world's problems with resistant bacteria?
2023, Sustainable Materials and TechnologiesMoringa oleifera gum capped MgO nanoparticles: Synthesis, characterization, cyto- and ecotoxicity assessment
2023, International Journal of Biological MacromoleculesNanosystems of plant-based pigments and its relationship with oxidative stress
2020, Food and Chemical ToxicologyCitation Excerpt :Finally, in order to produce nanoscale particles whit this technology, some experimental considerations are necessary. For example 1) the influences of process parameters (e.g. the spray mesh size, the spray rate intensity, the drying gas inlet temperature, and the drying gas flow rate); 2) the solid concentration (which influences the feed rate, particle size, and outlet temperature); 3) the selection of the solvent and mixing ratio (which must be based on the solubilization of the bioactive compound and the encapsulating wall materials); and 4) the selection of suitable wall material (based on mechanical strength, high encapsulation efficiency, and final viscosity) (Arpagaus et al., 2017; Gharsallaoui et al., 2007; Schoubben et al., 2013). Extrusion: The nanoextrusion technique is based on the immobilization of the active core material into in a polysaccharide gel, which is then put in contact with a multivalent ion (Teixeira da Silva et al., 2014).
Production of food bioactive-loaded nanoparticles by nano spray drying
2019, Nanoencapsulation of Food Ingredients by Specialized Equipment: Volume 3 in the Nanoencapsulation in the Food Industry seriesNano spray drying for encapsulation of pharmaceuticals
2018, International Journal of PharmaceuticsCitation Excerpt :Chitosan offers several advantages for mucosal delivery, such as low toxicity and good biodegradability as well as antibacterial activity (Cerchiara et al., 2015; Dimer et al., 2015a; Merchant et al., 2014; Ngan et al., 2014; Nguyen et al., 2017; Rampino et al., 2013). Leucine is a very popular dispersion enhancer to increase the flowability of nano spray dried particles, as shown in various pulmonary drug delivery studies (Aquino et al., 2014; Behara et al., 2014a, 2014b, 2014c; Dimer et al., 2015a; Feng et al., 2011; Guo and Li, 2013; Kaewjan and Srichana, 2016; Merchant et al., 2014; Schoubben et al., 2014, 2013a, 2013b, 2015; Son et al., 2013a; Yang et al., 2015). The ideal aerodynamic particle diameter for efficient delivery into the deep lung is about 1–5 µm, which allows penetration and deposition in the alveolar regions.
Reshaping antibiotics through hydrophobic drug-bile acid ionic complexation enhances activity against Staphylococcus aureus biofilms
2017, International Journal of PharmaceuticsCitation Excerpt :This implies shorter time to market and a series of advantages linked to ease of preparation and storage. In fact, these complexes can form spontaneously in water by choosing proper ligands and metals, as shown in our previous works (Giovagnoli et al., 2013; Schoubben et al., 2013). Such complexes can have variable physicochemical properties according to the kind of ligand chosen.