Novel perspectives in the tuberculosis treatment: Administration of isoniazid through the skin

Advanced drug delivery and therapeutic strategies for tuberculosis treatment

Tuberculosis (TB) remains a significant global health challenge, necessitating innovative approaches for effective treatment. Conventional TB therapy encounters several limitations, including extended treatment duration, drug resistance, patient noncompliance, poor bioavailability, and suboptimal targeting. Advanced drug delivery strategies have emerged as a promising approach to address these challenges. They have the potential to enhance therapeutic outcomes and improve TB patient compliance by providing benefits such as multiple drug encapsulation, sustained release, targeted delivery, reduced dosing frequency, and minimal side effects. This review examines the current landscape of drug delivery strategies for effective TB management, specifically highlighting lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, emulsion-based systems, carbon nanotubes, graphene, and hydrogels as promising approaches. Furthermore, emerging therapeutic strategies like targeted therapy, long-acting therapeutics, extrapulmonary therapy, phototherapy, and immunotherapy are emphasized. The review also discusses the future trajectory and challenges of developing drug delivery systems for TB. In conclusion, nanomedicine has made substantial progress in addressing the challenges posed by conventional TB drugs. Moreover, by harnessing the unique targeting abilities, extended duration of action, and specificity of advanced therapeutics, innovative solutions are offered that have the potential to revolutionize TB therapy, thereby enhancing treatment outcomes and patient compliance.

Nanofiber mats functionalized with Mentha piperita essential oil stabilized in a chitosan-based emulsion designed via an electrospinning technique

A nanostructured device based on poly(vinyl alcohol) (PVA) loaded with a cross-linked chitosan (CH) emulsion, soy lecithin, and peppermint essential oil (Mentha piperita) was designed for topical applications using an electrospinning instrument coupled to a rotary drum collector. Different suspensions were obtained by varying the PVA to emulsion ratio (PVA:Em) 87.5:12.5, 82:18, and 75:25, using a PVA solution as a control. ATR-FTIR spectra confirmed the interactions among the components of the system. Scanning electron microscopy (SEM) of the mats evinced that the aligned fiber diameter decreased with higher proportions of emulsion while dynamic mechanical analysis (DMA) revealed a decrease in the storage modulus. The entrapment of the functionalized emulsions not only improved the elongation of the matrices but also provided them with greater structural integrity compared to the single PVA matrix. The most favorable formulation in terms of mechanical properties was found to be the 82:18 ratio. After 1 h of close contact between the 82:18 matrix and a porcine skin explant, the latter was examined by confocal microscopy, which revealed the localization of the essential oil mainly on the surface of the stratum corneum (SC).However, after 7 h of contact, the distribution of the peppermint EO throughout the viable epidermis was observed, which was further supported by ATR-FTIR studies. Tailored electrospun matrices would have potential applications as devices for topical or transdermal treatments due to their vehiculization role that allows the diffusion of peppermint essential oil as a skin penetration enhancer.

An Insight into Advances in Developing Nanotechnology Based Therapeutics, Drug Delivery, Diagnostics and Vaccines: Multidimensional Applications in Tuberculosis Disease Management

Tuberculosis (TB), one of the deadliest contagious diseases, is a major concern worldwide. Long-term treatment, a high pill burden, limited compliance, and strict administration schedules are all variables that contribute to the development of MDR and XDR tuberculosis patients. The rise of multidrug-resistant strains and a scarcity of anti-TB medications pose a threat to TB control in the future. As a result, a strong and effective system is required to overcome technological limitations and improve the efficacy of therapeutic medications, which is still a huge problem for pharmacological technology. Nanotechnology offers an interesting opportunity for accurate identification of mycobacterial strains and improved medication treatment possibilities for tuberculosis. Nano medicine in tuberculosis is an emerging research field that provides the possibility of efficient medication delivery using nanoparticles and a decrease in drug dosages and adverse effects to boost patient compliance with therapy and recovery. Due to their fascinating characteristics, this strategy is useful in overcoming the abnormalities associated with traditional therapy and leads to some optimization of the therapeutic impact. It also decreases the dosing frequency and eliminates the problem of low compliance. To develop modern diagnosis techniques, upgraded treatment, and possible prevention of tuberculosis, the nanoparticle-based tests have demonstrated considerable advances. The literature search was conducted using Scopus, PubMed, Google Scholar, and Elsevier databases only. This article examines the possibility of employing nanotechnology for TB diagnosis, nanotechnology-based medicine delivery systems, and prevention for the successful elimination of TB illnesses.

Current nanotechnological strategies using lipids, carbohydrates, proteins and metal conjugates-based carrier systems for diagnosis and treatment of tuberculosis - A review

Tuberculosis is a fatal disease caused by Mycobacterium tuberculosis with highest morbidity and mortality every year. The evolution of anti-TB drugs is promising in controlling and treating TB. Yet, the drug response varies depending on the bacterial load and host immunological profiles. The prolonged anti-TB treatment regimen and high pill burden leads to poor adherence to treatment and acquired drug resistance. In the clinical arena, sustainable nanotechnology improves the targeted strategies leading to enhance therapeutic recovery with minimum treatment duration and virtuous drug adherence. Determinants of nanosystems are the size, nature, formulation techniques, stable dosing patterns, bioavailability and toxicity. In the treatment of chronic illness, nanomedicines inclusive of biological macromolecules such as lipids, peptides, and nucleic acids occur to be a successive alternative to synthetic carriers. Most biological nanomaterials possess antimicrobial properties with other intrinsic characteristics. Recently, the pulmonary delivery of anti-TB drugs through polymeric nanocarrier systems is shown to be effective in achieving optimal drug levels in lungs for longer duration, enhanced tissue permeation and sustained systemic clearance. This thematic review provides a holistic insight into the nanodelivery systems pertinent to the therapeutic applications in pulmonary tuberculosis describing the choice of carriers, optimized process, metabolic action and excretion processes.

The Molecular Mechanism of Propylene Glycol Monocaprylate on Skin Retention: Probing the Dual Roles on the Molecular Mobility and Collagen Connection in Roflumilast Cream

The present work was to construct a roflumilast (ROF) cream for the treatment of psoriasis and clarify the dual roles of propylene glycol monocaprylate (PGM) in both molecular mobility of the cream, and drug-skin miscibility via drug-PGM-ceramide and drug-PGM-collagen intermolecular interaction. The cream formulation was screened through the stability study and in vitro skin administration study, optimized by Plackett-Burman and Box-Behnken design, and finally verified by the in vivo tissue distribution study. PGM demonstrated a significant drug skin retention enhancement effect (R_{max in vivo} = 19.5 μg/g). It increased the molecular mobility of the oil phase of the cream by decreasing the molecular interaction of oil molecules proven by the rheology study (E_c = 3.73 × 10^-4 mJ·m^-3). More importantly, because of the good stratum corneum (SC) compatibility (∆H =  - 403.88 J/g), PGM promoted an orderly flow of SC lipids (X-ray scattering, ΔLPP = 1.18 nm) and entered the viable epidermis/dermis (VE/DE) in large quantities (R_PGM = 1186 μg/g), acting as a bridge to connect the drug to collagen through two H-bonds (Length_H-bond = 2.846 Å and 3.313 Å), thus increasing the miscibility of drug and VE/DE significantly (∆H =  - 310.10 J/g, E_mix = 21.66 kcal/mol). In this study, a ROF cream was developed successfully and the effect of PGM on the skin retention was clarified at molecular level.

Molecular perspective of efficiency and safety problems of chemical enhancers: bottlenecks and recent advances

Chemical penetration enhancer (CPE) is a preferred approach to improve drug permeability through the skin, due to its unique advantages of simple use and high compatibility. However, CPEs efficiency and safety problems frequently arise, which greatly restrains the further application in transdermal drug delivery systems (TDDS). To get access to the root of problems, the efficiency and safety of CPEs are reviewed especially from molecular perspectives, which include (1) the possible factors of CPEs low efficiency; (2) the possible contribution of CPEs in the evolution of safety problems such as skin irritation and allergic reaction; (3) the interactive relationship between CPEs efficiency and safety, as well as the bottlenecks of achieving their balance. More importantly, based on these, recent advances are summarized in improving efficiency or safety of CPEs, which offers a guidance of rationally selecting CPEs in future research.

Application of Green Nanoemulsion for Elimination of Rifampicin from a Bulk Aqueous Solution

The study aimed to prepare green nanoemulsion (GNE) multi-components ((water/dimethyl sulfoxide-transcutol/isopropyl alcohol/capmul MCM C8 (CMC8)) to remove rifampicin (RIF) from a contaminated aqueous bulk solution. Pseudo ternary phase diagrams dictated several batches of GNE prepared following the reported method. Selected nanoemulsions (NF1-NF5) were characterized for morphology, globular size, size distribution (polydispersity index, PDI), viscosity, zeta potential, refractive index (RI), and free-thaw kinetic stability. They were investigated for percent removal efficiency (%RE) of RIF from the bulk aqueous solution for varied time intervals (10-60 min). Finally, scanning electron microscopy-energy dispersive x-ray (SEM-EDX) and inductive coupled plasma-optical emission system (ICP-OE) were used to confirm the extraction of trace content of dimethyl sulfoxide (DMSO) and others in the treated water. Considering the data obtained for globule size, PDI, viscosity, zeta potential, freeze-thaw stability, and refractive index, NF5 was the most suitable for RIF removal. The largest %RE value (91.7%) was related to NF5, which may be prudent to correlate with the lowest value (~39 nm) of size (maximum surface area available for contact adsorption), PDI (0.112), and viscosity (82 cP). Moreover, %RE was profoundly influenced by the content of CMC8 and the aqueous phase. These two phases had immense impact on the viscosity, size, and RI. The percent content of water, Smix, and CMC8 were 15% w/w), 60% w/w, and 25% w/w, respectively in NF5. SEM-EDX and ICP-OE confirmed the absence of DMSO and other hydrophilic components in the treated water. Thus, efficient NF5 could be a promising option to the conventional method to decontaminate the polluted aqueous system.

Nanotechnology-based lipid systems applied to resistant bacterial control: A review of their use in the past two decades

The rate of infections caused by resistant bacteria to the antimicrobials available for human use grows exponentially every year, which generates major impacts on human health and the world economy. In the last two decades, human beings can witness the expressive increase in the Science and Technology worldwide, and areas such as Health Sciences have benefited from these advances in favor of human health, such as the advent of Pharmaceutical Nanotechnology as an important approach applied for bacterial infections treatment with resistance profile to available antibiotics. This review of the scientific literature brings the applicability of nanotechnology-based lipid systems as an innovative tool in the improvement of bacterial infections treatment. Important studies involving the use of liposomes, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, microemulsions and lipid nanocapsules were verified in the period from 2000 to 2020, where important scientific results were found and will serve as a basis for the use of these systems to remain in constant updating. This manuscript shows the use of these drug delivery systems as potential vehicles for antibacterial compounds, which opens a new hope in the complement of the antibacterial therapeutic arsenal. Important studies developed in the last 20 years are present in this review, and thus guarantees an update on the use of these drug delivery systems for researchers from different areas of Health Sciences.

Experimental Solubility, Thermodynamic/Computational Validations, and GastroPlus-Based In Silico Prediction for Subcutaneous Delivery of Rifampicin

We focused to explore a suitable solvent for rifampicin (RIF) recommended for subcutaneous (sub-Q) delivery [ethylene glycol (EG), propylene glycol (PG), tween 20, polyethylene glycol-400 (PEG400), oleic acid (OA), N-methyl-2-pyrrolidone (NMP), cremophor-EL (CEL), ethyl oleate (EO), methanol, and glycerol] followed by computational validations and in-silico prediction using GastroPlus. The experimental solubility was conducted over temperature ranges T = 298.2-318.2 K) and fixed pressure (p = 0.1 MPa) followed by validation employing computational models (Apelblat, and van't Hoff). Moreover, the HSPiP solubility software provided the Hansen solubility parameters. At T = 318.2K, the estimated maximum solubility (in term of mole fraction) values of the drug were in order of NMP (11.9 × 10^-2) ˃ methanol (6.8 × 10^-2) ˃ PEG400 (4.8 × 10^-2) ˃ tween 20 (3.4 × 10^-2). The drug dissolution was endothermic process and entropy driven as evident from "apparent thermodynamic analysis". The activity coefficients confirmed facilitated RIF-NMP interactions for increased solubility among them. Eventually, GastroPlus predicted the impact of critical input parameters on major pharmacokinetics responses after sub-Q delivery as compared to oral delivery. Thus, NMP may be the best solvent for sub-Q delivery of RIF to treat skin tuberculosis (local and systemic) and cutaneous related disease at explored concentration.

Transbuccal delivery of metal complexes of isoniazid as an alternative to overcome antimicrobial resistance problems

In isolated isoniazid (INH)-resistant strains, deletion or mutations in thekatGgene have been identified, which result in loss of catalase-peroxidase activity. This enzyme plays a key role in the activation of this prodrug. As an alternative, the coordination of the INH to metal complexes has been purposed to activate it regardless of enzyme functionality. Although pentacyanido(isoniazid)ferrate(II) complexes have shown to be effective against resistant strains of Mycobacterium tuberculosis, low oral bioavailability was found. In this context, buccal mucosa was selected as an alternative route to the metal complex delivery. Moreover, oral manifestations of tuberculosis(TB) have been observed in some patients, particularly when resistant strains are present, and no therapeutic options are currently available on the market. Pentacyanidoferrate (PCF-INH) and Prussian-blue (PB-INH) complexes were initially prepared and characterized, followed by buccal permeability studies in Franz-type diffusion cells. The electrochemical potential of the complexes demonstrated their ability to self-activate. Job's method suggested the presence of structural defects in PB-INH complexes, which was correlated with permeability results. In fact, PB-INH showed a higher dissociation rate in salt-rich aqueous medium and thus a high transport rate of INH through the buccal mucosa. Its passage through the tissue would not be possible due to the high molecular size. PCF-INH, in turn, presented a lower dissociation rate in the salt-rich aqueous medium, justifying its slower transport rate through the tissue. Taken together, these results suggest that INH-based metal complexes may be efficiently administered through the buccal route, impacting on both oral bioavailability and microbial resistance.

Transbuccal Delivery of Isoniazid: Ex Vivo Permeability and Drug-Surfactant Interaction Studies

The oral administration of isoniazid (INH) may lead to discontinuation of tuberculosis treatment due to drug-related hepatotoxicity events, and thus, the transbuccal delivery of this drug was investigated, for the first time, as an alternative administration route. Ex vivo permeability assays were performed in Franz-type diffusion chambers, applying INH alone and in combination with sodium dodecyl sulfate (SDS) and sodium taurocholate (ST). After confirming the formation of micelle structures by dynamic light scattering analysis, UV-visible spectroscopy and zeta potential analyses were used to investigate drug-micelle interactions. In zeta potential analyses, no electrostatical interactions were identified for both surfactants in saliva buffer pH 6.8. Spectrophotometric analyses, in turn, indicated chemical interactions between INH and SDS in both pH values (2.0 and 6.8) whereas no interaction between the drug and ST was observed. Despite the interaction between SDS and drug, this surfactant increased the buccal transport rate of INH by approximately 11 times when compared with the control. In contrast, ST did not increase the drug permeability. The INH retention in SDS-treated mucosa was significantly higher when compared with the control and an effect on intercellular lipids was suggested. In vivo studies are needed to confirm the high INH absorption found here. Grapical abstract.

Transbuccal delivery of benznidazole associated with monoterpenes: permeation studies and mechanistic insights

Benznidazole (BZN) represents the only drug currently available for the treatment of Chagas disease in most endemic countries. When administered orally, high doses are required due to its extensive hepatic metabolism and its toxicity represents the main reason for treatment withdrawals. Because of these complications, transbuccal administration of BZN was investigated. This route avoids the first-pass hepatic metabolism and presents high permeability, with direct access to the systemic circulation. BZN was applied on porcine buccal mucosa after pretreatment with pure eugenol, carvacrol or limonene. Thermal (DSC) and spectroscopic (FT-IR) analyzes were performed to investigate the mechanisms of drug absorption enhancement. The permeability coefficient values of BZN increased 2.6, 2.9 and 4.9-fold after pretreatment with eugenol, carvacrol and limonene, respectively. The lag time, in turn, was shortened in the pretreated samples. The DSC and FT-IR analyzes suggested that transport of BZN through the buccal mucosa is associated with log P and size of monoterpenes. Limonene, the most effective absorption enhancer, contributed to greater interaction with non-polar domains of the buccal epithelium. Overall, BZN showed to be efficiently transported through the buccal route, but in vivo pharmacokinetic studies should be performed to confirm these findings.

Novel Approach for Transdermal Delivery of Rifampicin to Induce Synergistic Antimycobacterial Effects Against Cutaneous and Systemic Tuberculosis Using a Cationic Nanoemulsion Gel

Purpose

This study demonstrated improved transdermal delivery of rifampicin-loaded cationic nanoemulsion gel to treat systemic and cutaneous tuberculosis using capmul, labrasol, and acconon, which exert anti-Mycobacterium activities. This approach enhanced drug permeation across the skin, increased therapeutic efficacy, and reduced dose-related side effects.

Methods

Design Expert^® was used to optimize formulations (S_mix ratio and capmul as independent factors), which were prepared using a slow spontaneous titration method. The optimized nanoemulsion was incorporated into carbopol gel to allow for topical application and comparative assessments. Nanoemulsions and gels were evaluated for size, size distribution, shape, zeta potential, percent spread, viscosity, in vitro hemolysis, in vitro release, and ex vivo skin permeation and deposition. A mechanistic evaluation was performed using scanning electron microscopy. Furthermore, in vivo pharmacokinetic and irritation studies were performed.

Results

The optimized cationic nanoemulsion (OCNE-1) was characterized by small particle size (≤100 nm), had optimal viscosity, percent spread, zeta potential, and percent drug release, and was hemocompatible. The OCNE-1T gel exhibited higher permeation flux (51.32 ± 0.5 µg/cm² hr), permeation coefficient (2.566 ± 0.08 cm/hr), drug deposition (994.404 µg/cm²), and enhancement ratio (7.16) than those of the OCNE-1 nanoemulsion or drug solution. Scanning electron microscopy was used to characterize the mechanism of enhanced permeation. An In vivo study showed that the C_max and area under the curve following transdermal application were 4.34- and 4.74-fold higher than those following oral administration.

Conclusion

Transdermal delivery of rifampicin could be a promising alternative to conventional approaches to treat systemic and local tuberculosis, and other bacterial infections.

Cocrystallization as a novel approach to enhance the transdermal administration of meloxicam

Despite its large effectiveness, the long-term oral administration of high doses of meloxicam (MLX) may lead to gastrointestinal events such as abdominal pain, diarrhea, dyspepsia, ulceration, hemorrhage, and gastrointestinal perforation. Moreover, the pH-dependent solubility of MLX makes the development of new oral formulations even more challenging. As an alternative to overcome these limitations, the transdermal delivery of this drug has been purposed. Although various physical and chemical approaches to enhance the absorption of MLX may be found in literature, the use of cocrystallization has not been reported so far. Cutaneous permeation of MLX and 1:1 meloxicam-salicylic acid cocrystal (MLX-SLC) were evaluated using Franz diffusion cells. Cocrystal was suspended in an aqueous solution and in a gel to evaluate the vehicle effect on permeation parameters. In aqueous medium, the cocrystallization showed to enhance the drug permeation coefficient from 1.38 to 2.15 × 10^-3 cm/h. MLX-SLC generated supersaturation with respect to the drug during dissolution studies simulating the conditions in the Franz cell donor chamber. This greater amount of free drug in the solution could contribute to explain the higher transdermal absorption and shorter lag time of this system. In addition, the acidic coformer ionization led to a pH reduction from 7.4 to 5.8, which, in turn, provided an increase in the unionized species of the drug, enhancing its permeation rate. The gel containing cocrystals reduced MLX permeation rate significantly (P = 0.42 × 10^-3 cm/h), which was attributed to its higher viscosity.

Chemical Enhancer: A Simplistic Way to Modulate Barrier Function of the Stratum Corneum

Human skin could be a prime target to deliver drugs into the human body as it is the largest organ of human body. However, the main challenge of delivering drug into the skin is the stratum corneum (SC), the outer layer of epidermis, which performs the main barrier function of the skin. Scientists have developed several techniques to overcome the barrier properties of the skin, which include other physical and chemical techniques. The most common and convenient technique is to use special formulation additives (chemical enhancers, CEs) which either drags the drug molecule along with it or make changes in the SC structure, thereby allowing the drug molecule to penetrate in to the SC. The main focus is to deliver drugs in the certain layers of the skin (for topical delivery) or ensuring proper percutaneous absorption (for transdermal delivery). However, skin drug delivery is still very challenging as different CEs act in different ways on the skin and they have different types of interaction with different drugs. Therefore, proper understanding on the mechanism of action of CE is mandatory. In this article, the effect of several CEs on skin has been reviewed based on the published articles. The main aim is to compile the recent knowledge on skin-CE interaction in order to design a topical and transdermal formulation efficiently. A properly designed formulation would help the drug either to deposit into the target layer or to cross the barrier membrane to reach the systemic circulation.

Study of Anti-Tuberculosis Activity Behaviour of Natural Kaurane and Trachylobane Diterpenes Compared with Structural Properties Obtained by Theoretical Calculations

A set of seven diterpenes, three kauranes and four trachylobanes, isolated from the African plant Psiadia punctulata were assayed against Mycobacterium tuberculosis and reached activity comparable with cycloserine, a second line drug used to treat tuberculosis (TB). Several structural properties of those diterpenes, such as lipophilicity, HOMO and LUMO energies, charge density, and intramolecular hydrogen bond (IHB) formation, were obtained by theoretical calculations and compared with their activities. Peculiar correlations were observed, especially between activity, lipophilicity and IHB formation.

Lipid- and Polymer-Based Nanostructures for Cutaneous Delivery of Curcumin

It is well-known that nanoencapsulation may overcome biopharmaceutical limitations of curcumin (CUR), but studies regarding the contribution of the vesicular nature of CUR-loaded nanoparticles on skin permeation are still scarce. Therefore, the effect of three colloidal systems (solid lipid nanoparticles (SLN), nanoemulsion (NE), and polymeric nanoparticles (NP)) on the control of cutaneous permeation of CUR was investigated in porcine ear skin/Franz diffusion cells. Colloidal suspensions were designed to present a similar particle size (±170 nm), narrow size distribution (PdI < 0.2), and high entrapment efficiency (>99%). Zeta potential values were -0.13, -9.68 and -36.7 mV for the CUR-loaded NP, SLN and NE, respectively. Nanoencapsulation resulted in a cumulative amount of CUR in the more superficial layers of the skin. NP significantly enhanced the compound retention in the epidermis, which was approximately 2.49- and 3.32-fold more than SLN and NE, respectively. The CUR levels into the dermis were significantly increased after treatment with NE, which may be associated with repulsion phenomena in surface skin. Therefore, a more superficial or deeper action of CUR on the skin may be obtained depending on nanostructure type. While NPs are more effective in upper skin layers, NE should be prioritized when a dermal action for the CUR is required.

The formulation of nanomedicines for treating tuberculosis

Recent estimates indicate that tuberculosis (TB) is the leading cause of death worldwide, alongside the human immunodeficiency virus (HIV) infection. The current treatment is effective, but is associated with severe adverse-effects and noncompliance to prescribed regimens. An alternative route of drug delivery may improve the performance of existing drugs, which may have a key importance in TB control and eradication. Recent advances and emerging technologies in nanoscale systems, particularly nanoparticles (NPs), have the potential to transform such approach to human health and disease. Until now, several nanodelivery systems for the pulmonary administration of anti-TB drugs have been intensively studied and their utility as an alternative to the classical TB treatment has been suggested. In this context, this review provides a comprehensive analysis of recent progress in nanodelivery systems for pulmonary administration of anti-TB drugs. Additionally, more convenient and cost-effective alternatives for the lung delivery, different types of NPs for oral and topical are also being considered, and summarized in this review. Lastly, the future of this growing field and its potential impact will be discussed.

In vitro–in vivo–in silico simulation studies of anti-tubercular drugs doped with a self nanoemulsifying drug delivery system

This study aimed to formulate a self-nanoemulsifying drug delivery system (SNEDDS) for enhanced pharmacokinetic (PK) behavior of rifampicin and isoniazid using excipients holding innate anti-mycobacterial activity followed within vivo–in silicopredictions using GastroPlus™.