Nanotechnology based approaches to enhance aqueous solubility and bioavailability of griseofulvin: A literature survey

Pharmaceutical approaches for enhancing solubility and oral bioavailability of poorly soluble drugs

High solubility in water and physiological fluids is an indispensable requirement for the pharmacological efficacy of an active pharmaceutical ingredient. Indeed, it is well established that pharmaceutical substances exhibiting limited solubility in water are inclined towards diminished and inconsistent absorption following oral administration, consequently resulting in variability in therapeutic outcomes. The current advancements in combinatorial chemistry and pharmaceutical design have facilitated the creation of drug candidates characterized by increased lipophilicity, elevated molecular size, and reduced aqueous solubility. Undoubtedly, the issue of poorly water-soluble medications has been progressively escalating over recent years. Indeed, 40% of the top 200 oral medications marketed in the United States, 33% of drugs listed in the US pharmacopoeia, 75% of compounds under development and 90% of new chemical entities are insufficiently water-soluble compounds. In order to address this obstacle, formulation scientists employ a variety of approaches, encompassing both physical and chemical methods such as prodrug synthesis, salt formation, solid dispersions formation, hydrotropic substances utilization, solubilizing agents incorporation, cosolvent addition, polymorphism exploration, cocrystal creation, cyclodextrins complexation, lipid formulations, particle size reduction and nanoformulation techniques. Despite the utilization of these diverse approaches, the primary reason for the failure in new drug development persists as the poor aqueous solubility of pharmaceutical compounds. This paper, therefore, delves into the foundational principles that underpin the implementation of various formulation strategies, along with a discussion on the respective advantages and drawbacks associated with each approach. Additionally, a discourse is provided regarding methodological frameworks for making informed decisions on selecting an appropriate formulation strategy to effectively tackle the key challenges posed during the development of a poorly water-soluble drug candidate.

Ionic resorcinarenes as drug solubilization agents in water

Resorcinarenes are capable of host-guest complexation with small molecules, however, they are less studied as pharmaceutical drug delivery aids. This article reports on the aqueous-solubility enhancing effect of an octa-sulfonated resorcinarene and a C-hydroxybenzyl ammonium resorcinarene chloride on three hydrophobic drugs: isoniazid, caffeine, and griseofulvin. The findings are backed by dynamic light scattering, isothermal calorimetric titration, and nuclear magnetic resonance experiments in water. Aqueous mixtures of equal volumes of drug compounds and resorcinarene solutions produced a more soluble and clearer unit than solutions of pure drug compounds in water. Light scattering experiments revealed shifts in particle sizes of pure drug compounds to the range of resorcinarene hosts. 1H NMR measurements of resorcinarene-drug mixtures confirmed interactions with shift changes ranging from -0.20 to 0.81 ppm. Binding affinities quantified through ITC experiments ranged between 0.54 and 211 mM, signifying interactions between resorcinarenes and drug compounds necessary for the solubility of the drugs. Cytotoxicity studies suggest that resorcinarenes alone, or complexed with any of the drug compounds, do not exert cytotoxicity in mammalian cells HEK-293 up to 200 μM. We herein propose a set of hydrophilic resorcinarene macrocycles as potential drug solubilizers.

Bile salt-enriched vs. non-enriched nanoparticles: comparison of their physicochemical characteristics and release pattern

Bile salts were first used in the preparation of nanoparticles due to their stabilizing effects. As time went by, they attracted much attention and were increasingly employed in fabricating nanoparticles. It is well accepted that the physicochemical properties of nanoparticles are influential factors in their permeation, distribution, elimination and degree of effectiveness as well as toxicity. The review of articles shows that the use of bile salts in the structure of nanocarriers may cause significant changes in their physicochemical properties. Hence, having information about the effect of bile salts on the properties of nanoparticles could be valuable in the design of optimal carriers. Herein, we review studies in which bile salts were used in preparing liposomes, niosomes and other nanocarriers. Furthermore, the effects of bile salts on entrapment efficiency, particle size, polydispersity index, zeta potential, release profile and stability of nanoparticles are pointed out. Finally, we debate how to take advantage of bile salts potential for preparing desirable nanocarriers.

Microemulsions, nanoemulsions and emulgels as carriers for antifungal antibiotics

According to estimates, up to 25% of the world's population has fungal skin diseases, making them the most prevalent infectious disease. Several chemical classes of antifungal drugs are available to treat fungal infections. However, the major challenges of conventional formulations of antifungal drugs include poor pharmacokinetic profiles like solubility, low permeability, side effects and decreased efficacy. Novel drug delivery is a promising approach for overcoming pharmacokinetic limitations and increasing the effectiveness of antibiotics. In this review, we have shed light on microemulsions, nanoemulsions, and emulgels as novel drug delivery approaches for the topical delivery of antifungal antibiotics. We believe these formulations have potential translational value and could be developed for treating fungal infections in humans.

Solubility and Pharmacokinetic Profile Improvement of Griseofulvin through Supercritical Carbon Dioxide-Assisted Complexation with HP-γ-Cyclodextrin

Since griseofulvin was marketed as a non-polyene antifungal antibiotic drug in 1958, its poor water solubility has been an issue for its wide applications, and over the last sixty years, many attempts have been made to increase its water solubility; however, a significant result has yet to be achieved. Through supercritical carbon dioxide-assisted cyclodextrin complexation with the addition of a trace amount of water-soluble polymer surfactant, the griseofulvin inclusion complex with HP-γ-cyclodextrin was prepared and confirmed. The 1:2 ratio of griseofulvin and HP-γ-cyclodextrin in the complex was determined based on its NMR study. After complexation with HP-γ-cyclodextrin, griseofulvin's water solubility was increased 477 times compared with that of griseofulvin alone, which is the best result thus far. The complex showed 90% of griseofulvin release in vitro in 10 min, in an in vivo dog pharmacokinetic study; the Cmax was increased from 0.52 µg/mL to 0.72 µg/mL, AUC0-12 was increased from 1.55 μg·h/mL to 2.75 μg·h/mL, the clearance was changed from 51.78 L/kg/h to 24.16 L/kg/h, and the half-life time was changed from 0.81 h to 1.56 h, indicating the obtained griseofulvin complex can be a more effective drug than griseofulvin alone.

Lipid-Based Nanocarrier Systems for Drug Delivery: Advances and Applications

Lipid-based nanocarriers have been extensively investigated for drug delivery due to their advantages including biodegradability, biocompatibility, nontoxicity, and nonimmunogenicity. However, the shortcomings of traditional lipid-based nanocarriers such as insufficient targeting, capture by the reticuloendothelial system, and fast elimination limit the efficiency of drug delivery and therapeutic efficacy. Therefore, a series of multifunctional lipid-based nanocarriers have been developed to enhance the accumulation of drugs in the lesion site, aiming for improved diagnosis and treatment of various diseases. In this review, we summarized the advances and applications of lipid-based nanocarriers from traditional to novel functional lipid preparations, including liposomes, stimuli-responsive lipid-based nanocarriers, ionizable lipid nanoparticles, lipid hybrid nanocarriers, as well as biomembrane-camouflaged nanoparticles, and further discussed the challenges and prospects of this system. This exploration may give a complete idea viewing the lipid-based nanocarriers as a promising choice for drug delivery system, and fuel the advancement of pharmaceutical products by materials innovation and nanotechnology.

CaCO3-based carriers with prolonged release property for antifungal drug delivery to hair follicles

Superficial fungal infections are of serious concern worldwide due to their morbidity and increasing distribution across the globe in this era of growing antimicrobial resistance. Delivery of antifungals to target...

Micronization of Thebaine Extracted from Papaver Bracteatum Lindl. Using Supercritical Fluid Technology

BACKGROUND

Thebaine, as a main opiate alkaloid extracted from papaveraceae plants, is widely used in the synthesis of many pharmaceutical ingredients such as buprenorphine, naltrexone, naloxone, and hydrocodone. Nevertheless, thebaine and related derivatives are often insoluble in aqueous media and have low bioavailability in digestive system.

OBJECTIVE

Reducing particle size and changing the morphology can mitigate the mentioned problem. In this study, extraction of thebaine from the capsule, steam, and root of Papaver bracteatum L. was optimized and micronization of extract components was developed to study of solubility.

METHODS

Extraction process was performed using supercritical carbon dioxide. Experimental central composite design was employed to determine the optimal conditions. Analysis of extract was done using validated HPLC method and mass spectrometry. Micronization process was performed using an inhouse developed supercritical technique. The nanoparticles were characterized using FESEM and Image J software. The Effect of micronization was explored on the solubility of extract components via ultraviolet spectroscopy.

RESULTS

The percentage of thebaine in dried capsule, steam, and root powder was about 1.05%, 0.31, and 0.83% respectively. The extraction results indicated that supercritical pressure has the greatest effect on the extraction yield. Analysis of FESEM images revealed that nanoparticles of extract components with particle size distribution of 5 to 100 nm were collected successfully.

CONCLUSIONS

The extraction results indicated that pressure has the greatest effect on the extraction yield. In vitro studies illustrated that the solubility of extract components increased up to 1.7 times during the micronization process.

HIGHLIGHTS

Expansion of supercritical methods as an effective method was performed for extracting and preparing alkaloids nanoparticles. This process led to improved oral bioavailability of alkaloids.

Fast-Dissolving Solid Dispersions for the Controlled Release of Poorly Watersoluble Drugs

Solid dispersions offer many advantages for oral drug delivery of poorly water-soluble drugs over other systems, including an increase in drug solubility and drug dissolution. An improvement in drug absorption and the higher bioavailability of active pharmaceutical ingredients in the gastrointestinal tract have been reported in various studies. In certain circumstances, a rapid pharmacological effect is required for patients. Fastdissolving solid dispersions provide an ideal formulation in such cases. This report will provide an overview of current studies on fast-dissolving solid dispersions, including not only solid dispersion powders with fast dissolution rates but also specific dose form for the controlled release of poorly water-soluble drugs. Specifically, the applications of fast-dissolving solid dispersions will be described in every specific case. Moreover, pharmaceutical approaches and the utilization of polymers will be summarized. The classification and analysis of fastdissolving solid dispersions could provide insight into strategies and potential applications in future drug delivery developments.

Micronization and coating of bioflavonoids extracted from Citrus sinensis L. peels to preparation of sustained release pellets using supercritical technique

Abstract

Bioflavonoids such as hesperidin and hesperetin as anticancer and antioxidant agents are widely used in the formulation of many herbal drugs. Recently, promising evidence for the prevention and treatment of COVID 19 using these compounds has been reported. Unfortunately, these compounds are often insoluble in aqueous media and have low stability in gastric acid environment. These factors reduced the bioavailability of related oral dosage forms in digestive system. Reduction of particle size and controlled release delivery system can decline the mentioned problems. In the presented research, extraction of bioflavonoids from Citrus sinensis L. (sweet orange) peels was performed using supercritical carbon dioxide. Experimental central composite design was employed for determination of optimal conditions. Qualification analysis was performed using LC–MS, and hesperidin and hesperetin were identified in herbal extract. Micronization and coating of the flavonoids nanoparticles on sugar spheres have been performed using an inhouse developed supercritical technique. Characterization of coated nanoparticles was done using FESEM and ImageJ software. The in vitro antioxidant activity of coated samples was investigated by ferrous ion chelating activity. According to the extraction results, concentration of ethanol as organic co-solvent has the greatest effect on the extraction yield. Analysis of FESEM images illustrated that nanoparticles of extract components with particle size distribution of 5–100 nm were coated successfully. The solubility and antioxidant activity of nanoparticles in aqueous media have increased significantly compared to original form. This process led to increasing dissolution rate and improving the oral bioavailability of flavonoids.

Graphical abstract

In Vitro Drug Release, Permeability, and Structural Test of Ciprofloxacin-Loaded Nanofibers

Nanofibers of the poorly water-soluble antibiotic ciprofloxacin (CIP) were fabricated in the form of an amorphous solid dispersion by using poly(vinyl pyrrolidone) as a polymer matrix, by the low-cost electrospinning method. The solubility of the nanofibers as well as their in vitro diffusion were remarkably higher than those of the CIP powder or the physical mixture of the two components. The fiber size and morphology were optimized, and it was found that the addition of the CIP to the electrospinning solution decreased the nanofiber diameter, leading to an increased specific surface area. Structural characterization confirmed the interactions between the drug and the polymer and the amorphous state of CIP inside the nanofibers. Since the solubility of CIP is pH-dependent, the in vitro solubility and dissolution studies were executed at different pH levels. The nanofiber sample with the finest morphology demonstrated a significant increase in solubility both in water and pH 7.4 buffer. Single medium and two-stage biorelevant dissolution studies were performed, and the release mechanism was described by mathematical models. Besides, in vitro diffusion from pH 6.8 to pH 7.4 notably increased when compared with the pure drug and physical mixture. Ciprofloxacin-loaded poly(vinyl pyrrolidone) (PVP) nanofibers can be considered as fast-dissolving formulations with improved physicochemical properties.

Lignin: Drug/Gene Delivery and Tissue Engineering Applications

Lignin is an abundant renewable natural biopolymer. Moreover, a significant development in lignin pretreatment and processing technologies has opened a new window to explore lignin and lignin-based bionanomaterials. In the last decade, lignin has been widely explored in different applications such as drug and gene delivery, tissue engineering, food science, water purification, biofuels, environmental, pharmaceuticals, nutraceutical, catalysis, and other interesting low-value-added energy applications. The complex nature and antioxidant, antimicrobial, and biocompatibility of lignin attracted its use in various biomedical applications because of ease of functionalization, availability of diverse functional sites, tunable physicochemical and mechanical properties. In addition to it, its diverse properties such as reactivity towards oxygen radical, metal chelation, renewable nature, biodegradability, favorable interaction with cells, nature to mimic the extracellular environment, and ease of nanoparticles preparation make it a very interesting material for biomedical use. Tremendous progress has been made in drug delivery and tissue engineering in recent years. However, still, it remains challenging to identify an ideal and compatible nanomaterial for biomedical applications. In this review, recent progress of lignin towards biomedical applications especially in drug delivery and in tissue engineering along with challenges, future possibilities have been comprehensively reviewed.

Biodegradable nanoparticles from prosopisylated cellulose as a platform for enhanced oral bioavailability of poorly water-soluble drugs

Bio-inspired nanotechnology-based strategies are potential platforms for enhanced dissolution and oral biovailability of poorly water-soluble drugs. In this study, a recently patented green biopolymer (Prosopis africana gum, PG) was compatibilized with microcrystalline cellulose (MCC), a conventional polysaccharide, via thermo-regulated coacervation to obtain PG-MCC (1:0, 1:1, 1:2, 2:1, and 0:1) rational blends and the nanoparticles developed with optimized (1:1) biocomposites (termed "prosopisylated cellulose") by combined homogenization-nanoprecipitation technique was engineered as a high circulating system for improved oral bioavailability of griseofulvin (GF), a model Biopharmaceutics Classification System (BCS) Class-II drug. The effects of biopolymer interaction on morphological and microstructural properties of drug-free biocomposites obtained were investigated by Fourier transform infra-red spectroscopy, scanning electron microscopy and x-ray diffractometry, while the physicochemical properties and in-vivo pharmacokinetics of GF-loaded nanoparticles were also ascertained. Optimized biocomposites revealed inter-molecular and intra-molecular hydrogen bonding between the hydroxyl group of MCC and polar components of PG, as well as reduction in crystallinity of MCC. Griseofulvin-loaded nanoparticles were stable, displayed particles with relatively smooth surfaces and average size of 26.18 ± 0.94 . nm, with zeta potential and polydispersity index of 32.1 ± 0.57 mV and 0.173 ± 0.06, respectively. Additionally, the nanoparticles showed good entrapment efficiency (86.51 ± 0.93 %), and marked improvement in griseofulvin dissolution when compared to free drug, with significantly (p < 0.05) higher GF release in basic than acidic PEG-reinforced simulated bio-microenvironments. Besides, x-ray diffractogram of GF-loaded nanoparticles showed amorphization with few characteristic peaks of GF while infra-red spectrum indicated broader principal peaks of GF and components compatibility. Furthermore, GF-loaded nanoparticles showed low plasma clearance with three-fold increase in systemic bioavailability of griseofulvin compared with free drug. These results showed that prosopisylated cellulose nanoparticles would be a facile approach to improve oral bioavailability of BCS class-II drugs and can be pursued as a new versatile drug delivery platform.

Core-shell nanostructures: perspectives towards drug delivery applications

Nanosystems have shown encouraging outcomes and substantial progress in the areas of drug delivery and biomedical applications. However, the controlled and targeted delivery of drugs or genes can be limited due to their physicochemical and functional properties. In this regard, core-shell type nanoparticles are promising nanocarrier systems for controlled and targeted drug delivery applications. These functional nanoparticles are emerging as a particular class of nanosystems because of their unique advantages, including high surface area, and easy surface modification and functionalization. Such unique advantages can facilitate the use of core-shell nanoparticles for the selective mingling of two or more different functional properties in a single nanosystem to achieve the desired physicochemical properties that are essential for effective targeted drug delivery. Several types of core-shell nanoparticles, such as metallic, magnetic, silica-based, upconversion, and carbon-based core-shell nanoparticles, have been designed and developed for drug delivery applications. Keeping the scope, demand, and challenges in view, the present review explores state-of-the-art developments and advances in core-shell nanoparticle systems, the desired structure-property relationships, newly generated properties, the effects of parameter control, surface modification, and functionalization, and, last but not least, their promising applications in the fields of drug delivery, biomedical applications, and tissue engineering. This review also supports significant future research for developing multi-core and shell-based functional nanosystems to investigate nano-therapies that are needed for advanced, precise, and personalized healthcare systems.

Insoluble Polymers in Solid Dispersions for Improving Bioavailability of Poorly Water-Soluble Drugs

In recent decades, solid dispersions have been demonstrated as an effective approach for improving the bioavailability of poorly water-soluble drugs, as have solid dispersion techniques that include the application of nanotechnology. Many studies have reported on the ability to change drug crystallinity and molecular interactions to enhance the dissolution rate of solid dispersions using hydrophilic carriers. However, numerous studies have indicated that insoluble carriers are also promising excipients in solid dispersions. In this report, an overview of solid dispersion strategies involving insoluble carriers has been provided. In addition to the role of solubility and dissolution enhancement, the perspectives of the use of these polymers in controlled release solid dispersions have been classified and discussed. Moreover, the compatibility between methods and carriers and between drug and carrier is mentioned. In general, this report on solid dispersions using insoluble carriers could provide a specific approach and/or a selection of these polymers for further formulation development and clinical applications.