Docetaxel microemulsion for enhanced oral bioavailability: Preparation and in vitro and in vivo evaluation

An overview of oral bioavailability enhancement through self-emulsifying drug delivery systems

INTRODUCTION

The pharmaceutical technologists face a lot of challenges and limitations when designing novel drug delivery systems such as low oral bioavailability of many drugs, primarily due to poor solubility, slow dissolution rates, limited permeability through gastrointestinal mucosa, and rapid degradation within the body.

AREAS COVERED

The biopharmaceutical classification (BCS) classification represents a map in drug delivery research. Numerous active ingredients are characterized by low bioavailability due to poor water solubility, especially active ingredients of BCS class II and IV. Self-emulsifying drug delivery systems (SEDDS) could act as game changer in order to overcome the challenges and limitations of poor bioavailability. In this review, timelines representing the launch of self-emulsifying drug delivery systems, their introduction to the pharmaceutical platform and their benefits will be discussed in detail.

EXPERT OPINION

The development of multifunctional systems capable of combining controlled release, targeted delivery, and diagnostic capabilities is a promising avenue. As the technology matures, self-microemulsifying drug delivery systems and self-nanoemulsifying drug delivery systems are likely to become a standard approach for delivering BCS class II and IV drugs, transforming the pharmaceutical landscape.

Glyceroniosomes for enhanced intestinal absorption of hydrochlorothiazide and lisinopril in their fixed dose combination

The objective was to investigate the effect of co-administration of hydrochlorothiazide and lisinopril as fixed dose combination on their intestinal absorption. The scope was extended to enhance intestinal absorption of both drugs. In situ rabbit intestinal absorption through the duodenum and jejuno-ileum was used to monitor membrane permeability of both drugs when perfused alone or in combination. Niosomes containing glycerols (glyceroniosomes) were loaded with both drugs. Glyceroniosomes comprised Span 60 or Tween 40 in combination with cholesterol and glycerol were prepared by bath sonication. Glyceroniosomes were characterized with respect to vesicle size, drug entrapment efficiency and were examined using transmission electron microscope (TEM). The prepared vesicles were nanosized spherical vesicles with average size of 202.4 nm and 108.8 nm for span free and span containing glyceroniosomes, respectively. The recorded Zeta potential values suggested good stability of the prepared formulations. Intestinal absorption studies reflected incomplete absorption of hydrocholothiazide and lisinopril correlating with their categorization as class IV and III drugs, respectively. Co-perfusion of both drugs reduced the intestinal absorption of lisinopril. Simultaneous encapsulation in glyceroniosomes enhanced the intestinal absorption of both drugs. Tween based systems were more efficient. The study introduced glyceroniosomes as carriers of simultaneous delivery of hydrochlorothiazide and lisinopril.

Maximum tolerated dose and toxicity evaluation of orally administered docetaxel granule in mice

Oral delivery of chemotherapy drugs is the most favorable and preferred route of drug administration. However, because of poor solubility and/or permeability, most chemotherapy drugs are given by intravenous administration. Docetaxel (DTX) is a potent chemotherapy drug that inhibits microtubular depolymerization and is widely used to treat numerous cancers. DTX is highly lipophilic and insoluble in water; thus, 50% polysorbate 80, which may cause hypersensitivity reactions and reduce drug uptake by tumor tissue, is used in the commercial DTX injection to dissolve DTX. Maximum tolerated dose (MTD) and toxicity are important to determine parameters in preclinical studies and to predict human dose in clinical trials. However, MTD and toxicity of oral DTX formulations have not been studied although various oral DTX formulations have been reported. We have previously developed oral DTX granule and demonstrated its ability to inhibit tumor growth. In this study, we aimed to systemically measure MTD and tissue distribution and evaluate the toxicity of oral DTX granule in mice. Oral DTX granule showed sex differences in toxicity and absorption. The MTD of DTX granule was determined at 50 mg/kg for female mice and 25 mg/kg for male mice. However, female mice had higher tissue absorption than male mice. At a very high dose (400 mg/kg), oral DTX granule induced kidney damage but did not influence the liver and the lungs. The study provides the fundamental data for future preclinical studies and clinical application of oral DTX formulations for cancers.

Progress in the Treatment of Central Nervous System Diseases Based on Nanosized Traditional Chinese Medicine

Traditional Chinese Medicine (TCM) is widely used in clinical practice to treat diseases related to central nervous system (CNS) damage. However, the blood-brain barrier (BBB) constitutes a significant impediment to the effective delivery of TCM, thus substantially diminishing its efficacy. Advances in nanotechnology and its applications in TCM (also known as nano-TCM) can deliver active ingredients or components of TCM across the BBB to the targeted brain region. This review provides an overview of the physiological and pathological mechanisms of the BBB and systematically classifies the common TCM used to treat CNS diseases and types of nanocarriers that effectively deliver TCM to the brain. Additionally, drug delivery strategies for nano-TCMs that utilize in vivo physiological properties or in vitro devices to bypass or cross the BBB are discussed. This review further focuses on the application of nano-TCMs in the treatment of various CNS diseases. Finally, this article anticipates a design strategy for nano-TCMs with higher delivery efficiency and probes their application potential in treating a wider range of CNS diseases.

Preparation, in vitro and in vivo evaluation of a novel mitiglinide microemulsions

This study aimed to prepare an o/w mitiglinide microemulsion (MTGME) to improve the drug solubility and bioavailability. The formulation of o/w MTGME was optimized by the solubility study of drug, pseudo-ternary phase diagram and Box-Behnken design successively. MTGME was characterized by dynamic laser light scattering (DLS), zeta potential and transmission electron microscopy (TEM), moreover, the storage stability, pharmacodynamics and pharmacokinetics were investigated. The optimal prescription for MTGME consisted of Maisine 35-1 (oil), Cremophor EL (surfactant) and propylene glycol (PG, cosurfactant). MTGME with a spherical dimension of 58.1 ± 5.86 nm was stable when stored at 4 °C for 3 months. The blood glucose levers (BGL) of diabetic mice were uniformly and significantly decreased by intragastric (i.g.) administration of 1-4 mg/kg MTGME, in which BGL (i.g. 4 mg/kg MTGME) was reduced by 69% during 24 h. The pharmacokinetics study of MTGME (i.g., 20 mg/kg) in Wistar rats showed higher plasma drug concentration (Cmax, 2.9 folds), larger area under curve (AUC, 4.6 folds) and oral bioavailability than those of MTG suspensions. Generally, the MTGME (o/w) showed good effect on controlling hyperglycemia. Therefore, microemulsion can be used as an effective oral drug delivery system to improve the bioavailability of MTG.

Self-nanoemulsifying drug delivery system (SNEDDS) of docetaxel and carvacrol synergizes the anticancer activity and enables safer toxicity profile: optimization, and in-vitro, ex-vivo and in-vivo pharmacokinetic evaluation

Docetaxel (DTX) is a first-line chemotherapeutic molecule with a broad-spectrum anticancer activity. On the other hand, carvacrol (CV) has anti-inflammatory, antioxidant, cytotoxic, and hepatoprotective properties that could reduce undue toxicity caused by DTX chemotherapy. Thus, in order to overcome the challenges posed by DTX's poor aqueous solubility, low permeability, hepatic first pass, and systemic toxicities, we have developed a novel solid self-nanoemulsifying drug delivery system (S-SNEDDS) co-loaded with DTX and CV. In the present investigation, liquid-SNEDDS (L-SNEDDS) were fabricated using Nigella sativa oil, Cremophor RH 40, and Ethanol which was converted into solid by lyophilization using Aerosil 200. The reconstituted CV-DTX-S-SNEDDS showed an average globule size of < 200 nm with promising flow properties (angle of repose θ: 33.22 ± 0.06). Additionally, 2.3-fold higher dissolution of DTX was observed from CV-DTX-S-SNEDDS after 6 h as compared to free DTX. Similar trend was followed in dialysis release experiments with 1.5-fold higher release within 24 h. Ex vivo permeation studies demonstrated significantly increased permeation of 1077.02 ± 12.72 μg/cm2 of CV-DTX-S-SNEDDS after 12 h. In vitro cell cytotoxicity studies revealed 5.2-fold reduction in IC50 as compared to free DTX in MDA-MB-231 cells. Formulation was able to induce higher apoptosis in cells treated with CV-DTX-S-SNEDDS as compared to free DTX and CV. It was evident from toxicity studies that CV-DTX-S-SNEDDS was well tolerated at higher dose where CV was able to manage the toxic effects of free DTX. In vivo pharmacokinetic study showed 3.4-fold increased Cmax and improved oral bioavailability as compared to free DTX. Thus, CV-DTX-S-SNEDDS could be an encouraging option for facilitating DTX oral therapy.

Application of Advanced Technologies-Nanotechnology, Genomics Technology, and 3D Printing Technology-In Precision Anesthesia: A Comprehensive Narrative Review

There has been increasing interest and rapid developments in precision medicine, which is a new medical concept and model based on individualized medicine with the joint application of genomics, bioinformatics engineering, and big data science. By applying numerous emerging medical frontier technologies, precision medicine could allow individualized and precise treatment for specific diseases and patients. This article reviews the application and progress of advanced technologies in the anesthesiology field, in which nanotechnology and genomics can provide more personalized anesthesia protocols, while 3D printing can yield more patient-friendly anesthesia supplies and technical training materials to improve the accuracy and efficiency of decision-making in anesthesiology. The objective of this manuscript is to analyze the recent scientific evidence on the application of nanotechnology in anesthesiology. It specifically focuses on nanomedicine, precision medicine, and clinical anesthesia. In addition, it also includes genomics and 3D printing. By studying the current research and advancements in these advanced technologies, this review aims to provide a deeper understanding of the potential impact of these advanced technologies on improving anesthesia techniques, personalized pain management, and advancing precision medicine in the field of anesthesia.

A review of FDA approved drugs and their formulations for the treatment of breast cancer

Breast cancer is one of the most diagnosed solid cancers globally. Extensive research has been going on for decades to meet the challenges of treating solid tumors with selective compounds. This article aims to summarize the therapeutic agents which are either being used or are currently under approval for use in the treatment or mitigation of breast cancer by the US FDA, to date. A structured search of bibliographic databases for previously published peer-reviewed research papers on registered molecules was explored and data was sorted in terms of various categories of drugs used in first line/adjuvant therapy for different stages of breast cancer. We included more than 300 peer-reviewed papers, including both research and reviews articles, in order to provide readers an useful comprehensive information. A list of 39 drugs are discussed along with their current status, dose protocols, mechanism of action, pharmacokinetics, possible side effects, and marketed formulations. Another interesting aspect of the article included focusing on novel formulations of these drugs which are currently in clinical trials or in the process of approval. This exhaustive review thus shall be a one-stop solution for researchers who are working in the areas of formulation development for these drugs.

Pentacyclic Triterpenes from Olive Leaves Formulated in Microemulsion: Characterization and Role in De Novo Lipogenesis in HepG2 Cells

Olea europaea L. leaves contain a wide variety of pentacyclic triterpenes (TTPs). TTPs exhibit many pharmacological activities, including antihyperlipidemic effects. Metabolic alterations, such as dyslipidemia, are an established risk factor for hepatocellular carcinoma (HCC). Therefore, the use of TTPs in the adjunctive treatment of HCC has been proposed as a possible method for the management of HCC. However, TTPs are characterized by poor water solubility, permeability, and bioavailability. In this work, a microemulsion (ME) loading a TTP-enriched extract (EXT) was developed, to overcome these limits and obtain a formulation for oral administration. The extract-loaded microemulsion (ME-EXT) was fully characterized, assessing its chemical and physical parameters and release characteristics, and the stability was evaluated for two months of storage at 4 °C and 25 °C. PAMPA (parallel artificial membrane permeability assay) was used to evaluate the influence of the formulation on the intestinal passive permeability of the TTPs across an artificial membrane. Furthermore, human hepatocarcinoma (HepG2) cells were used as a cellular model to evaluate the effect of EXT and ME-EXT on de novo lipogenesis induced by elevated glucose levels. The effect was evaluated by detecting fatty acid synthase expression levels and intracellular lipid accumulation. ME-EXT resulted as homogeneous dispersed-phase droplets, with significantly increased EXT aqueous solubility. Physical and chemical analyses showed the high stability of the formulation over 2 months. The formulation realized a prolonged release of TTPs, and permeation studies demonstrated that the formulation improved their passive permeability. Furthermore, the EXT reduced the lipid accumulation in HepG2 cells by inhibiting de novo lipogenesis, and the ME-EXT formulation enhanced the inhibitory activity of EXT on intracellular lipid accumulation.

A self-microemulsion enhances oral absorption of docetaxel by inhibiting P-glycoprotein and CYP metabolism

Oral absorption of docetaxel was limited by drug efflux pump p-glycoprotein (P-gp) and cytochrome P450 enzyme (CYP 450). Therefore, co-loading agent that inhibits P-gp and CYP450 in self-nanoemulsifying drug delivery systems (SMEs) is considered a promising strategy for oral delivery of docetaxel. In this study, curcumin was selected as an inhibitor of P-gp and CYP450, and it was co-encapsuled in SMEs to improve the oral bioavailability of docetaxel. SMEs quickly dispersed in water within 20 s, and the droplet size was 32.23 ± 2.21 nm. The release rate of curcumin from DC-SMEs was higher than that of docetaxel in vitro. Compared with free docetaxel, SMEs significantly increased the permeability of docetaxel by 4.6 times. And competitive experiments showed that the increased permeability was the result of inhibition of p-gp. The half-life and oral bioavailabilty of DC-SMEs increased about 1.7 times and 1.6 times than docetaxel SMEs, which indicated that its good pharmacokinetic behavior was related to the restriction of hepatic first-pass metabolism. In conclusion, DC-SME was an ideal platform to facilitate oral delivery of docetaxel through inhibited P-gp and CYP 450.

Brain Targeted Curcumin Loaded Turmeric Oil Microemulsion Protects Against Trimethyltin Induced Neurodegeneration in Adult Zebrafish: A Pharmacokinetic and Pharmacodynamic Insight

PURPOSE

Aromatic turmerone, a major constituent of turmeric oil, has been recently reported for proliferation of neural stem cell showing great potential for effective treatment in neurodegenerative disorders. However, its effect as oral brain targeted formulation for neuroprotection has not yet reported. The objective of the study was to investigate the pharmacokinetic of curcumin loaded turmeric oil microemulsion for brain targeting and probing the protective effect against trimethyltin induced neurodegeneration in adult zebrafish.

METHODS

Initially, in vivo plasma and brain pharmacokinetics was performed to determine improvement in relative bioavailability in rats followed by biodistribution and histopathological evaluation. Furthermore, the neuroprotective effect of the formulation was assessed in trimethyltin induced neurodegeneration model using adult zebrafish by behavioral analysis and biochemical analysis.

RESULTS

The in vivo plasma and brain pharmacokinetics showed 2-fold and 1.87-fold improvement respectively. Biodistribution study revealed significantly lower concentration in organs other than brain. Furthermore, curcumin microemulsion exhibited improved spatial memory by remembering the training and made correct choices after curcumin microemulsion treatment than other treatment groups. Histopathological evaluation confirmed neuroprotective effect on zebrafish brains. The biochemical analysis revealed reduced oxidative stress in curcumin microemulsion treated group.

CONCLUSIONS

Overall results showed a great potential of curcumin microemulsion for brain targeting in the effective treatment of neurological ailments.

Enhanced oral absorption of insulin: hydrophobic ion pairing and a self-microemulsifying drug delivery system using a D-optimal mixture design

The lipophilicity of a peptide drug can be considerably increased by hydrophobic ion pairing with amphiphilic counterions for successful incorporation into lipid-based formulations. Herein, to enhance the oral absorption of insulin (INS), a self-microemulsifying drug delivery system (SMEDDS) formulation was developed. Prior to optimization, INS was complexed with sodium n-octadecyl sulfate (SOS) to increase the loading into the SMEDDS. The INS–SOS complex was characterized via scanning electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and its dissociation behavior. The SMEDDS was optimized using a D-optimal mixture design with three independent variables including Capmul MCM (X₁, 9.31%), Labrasol (X₂, 49.77%), and Tetraglycol (X₃, 40.92%) and three response variables including droplet size (Y₁, 115.2 nm), INS stability (Y₂, 46.75%), and INS leakage (Y₃, 17.67%). The desirability function was 0.766, indicating excellent agreement between the predicted and experimental values. The stability of INS-SOS against gastrointestinal enzymes was noticeably improved in the SMEDDS, and the majority of INS remained in oil droplets during release. Following oral administration in diabetic rats, the optimized SMEDDS resulted in pharmacological availabilities of 3.23% (50 IU/kg) and 2.13% (100 IU/kg). Thus, the optimized SMEDDS is a good candidate for the practical development of oral delivery of peptide drugs such as INS.

Microemulsions Enhance the In Vitro Antioxidant Activity of Oleanolic Acid in RAW 264.7 Cells

Oleanolic acid (OA) is the main triterpenic acid of olive leaves known for numerous pharmacological properties, including antioxidant activity. However, it is poorly soluble in water and consequently with low bioavailability, which limits its pharmacological application. Microemulsions (MEs) are dispersed systems consisting of two immiscible phases that promote rapid solubilization and absorption in the gastrointestinal tract. To improve both solubility and intestinal permeability of this molecule, OA has been formulated in two different microemulsions (ME-1 and ME-2). A solubility screening was carried out to select the ME components, and pseudoternary phase diagrams were constructed to evaluate the region of existence and select the appropriate amount of the constituents. ME-1 was prepared using Capmul PG-8/NF as the oily phase, and Transcutol and Tween 20 (7:3) as surfactants, while ME-2 contained Nigella oil and Isopropil myristate as the oily phase, and Transcutol HP and Cremophor EL (2:1) as surfactants. The OA solubility was increased by 1000-fold and 3000-fold in ME-1-OA and ME-2-OA, respectively. The MEs’ droplet size and the PdI were evaluated, and the stability was assessed for 8 weeks by monitoring chemical and physical parameters. The parallel artificial membrane permeability assay (PAMPA) also demonstrated an enhanced intestinal permeability of both OA formulations compared with free OA. The potential ability of both MEs to enhance the bioactivity of OA against LPS-induced oxidative stress in RAW 264.7 murine macrophages was also investigated. Overall, this study suggests that both MEs promote a bio-enhancement of the protective action of OA against the LPS-induced pro-oxidant stress in macrophages. Overall, this study suggests that MEs could be an interesting formulation to improve OA oral bioavailability with potential clinical applications.

Self-Emulsifying Drug Delivery System Enhances Tissue Distribution of Cinnamaldehyde by Altering the Properties of the Mucus Layer

Oral delivery is considered the preferred route of administration due to its convenience and favorable compliance. However, this delivery often faces difficulties, such as poor solubility, limited absorption, and undesirable stability, especially for some volatile oils. The aim of this study was to develop self-emulsifying drug delivery systems (SEDDS) containing cinnamaldehyde (CA) to overcome these shortcomings. The CA-SEDDS were spherical and smooth with an average size of 14.96 ± 0.18 nm. Differential scanning calorimetry (DSC) and attenuated total reflection by Fourier transform infrared (ATR-FTIR) showed that CA has been successfully loaded into SEDDS. The accumulative release of CA-SEDDS (73.39%) was approximately 2.14-fold that of free CA when using simulated intestinal fluid as the release medium. A scanning electron microscope was used to observe the mucus network structure. Rheological tests found that CA-SEDDS can appropriately enhance the viscosity of the mucus system. We found from tissue distribution studies that CA was more widely distributed in various tissues in the CA-SEDDS group compared to the free CA group. The cinnamaldehyde and cinnamon acid also accumulated more in various tissues in the CA-SEDDS group than in the free CA group, especially in the kidney. These findings hinted that SEDDS exhibited lower irritation, good release, and penetration, which demonstrated great potential for utilizing CA. Our research supports the rational implications of SEDDS in delivering similar volatile substances by improving the solubility, mucus penetration, and stability, resulting in excellent clinical efficacy.

Effective Cancer Management: Inimitable Role of Phytochemical Based Nano- Formulations

BACKGROUND

Global cancer statistics defines the severity of disease even after significant research worldwide.

PROBLEM

Failure of the currently available treatment approaches, including surgery, radiation therapy and traditional chemotherapy.

AIM

The aim of this review is to discuss the role of phytochemical based nano-formulations for treatment of cancer.

DISCUSSION

In the past few decades, phytochemicals have gained popularity for acting as a potential anticancer treatment with low systemic toxicity, especially in terms of cell cycle control and cancer cell killing. Natural resources, with their immense structural variety, serve as a vital source of fresh, therapeutically useful new chemical entities for the treatment of cancer. Vinca alkaloids (VCR), vinblastine, vindesine, vinorelbine, taxanes (PTX), podophyllotoxin and its derivatives (etoposide (ETP), teniposide, camptothecin (CPT) and its derivatives (topotecan, irinotecan), anthracyclines (doxorubicin, daunorubicin, epirubicin, idarubicin, as natural products or their derivatives account for half of all anticancer drugs approved worldwide, and they have been developed utilising the knowledge learned from the natural small molecules or macromolecules. Trabectedin, an epothilone derivative, ixabepilone, and temsirolimus, three new anticancer medications launched in 2007, were derived from microbial origins. Current therapy regimens require selective drug targeting to enhance efficacy against cancer cells while normal cells remain unharmed. Modified medications and systems for drug delivery based on nanotechnology are in the process of being explored and launched in the industry for enhanced therapy and management of cancer, along with promising outcomes. Many obstacles related to cancer cell drug delivery can be overcome by using nano-particulate drug carriers, including enhancing the stability and solubility of the drug, prolonging half-lives of the drug in the blood, decreasing side effects to undesired organs, and increasing medication concentration at the desired site. The scientific initiatives and studies concerning the use of nanotechnology for some selective compounds derived from plants are discussed in this review article.

CONCLUSION

The present review highlights the phytochemical-based nanoformulations and their strategies in the development of novel systems of drug delivery such as nano-liposomes, functionalized nanoparticles (NPs), and polymer nano-conjugates, SNEDDS (Self nano emulsifying drug delivery system) as this review paper depicts, as well as their rewards over conventional systems of drug delivery, as evidenced by improved biological activity depicted in their in vitro and in vivo anticancer assays.

The influence on the oral bioavailability of solubilized and suspended drug in a lipid nanoparticle formulation: in vitro and in vivo evaluation

The present study investigated the oral bioavailability of celecoxib when incorporated into solid lipid nanoparticles either dissolved or suspended. In vitro drug release in different media, in vivo performance, and in vitro-in vivo correlation were conducted. The results revealed that the compound was successfully encapsulated into the nanocarriers with good physicochemical properties for oral administration. The in vitro release profiles followed the Weibull model, with significant differences between the formulations containing the solubilized and the suspended compound. Furthermore, in vitro release data could be used to rank the observed in vivo bioavailability. The relative bioavailability of celecoxib from the solid lipid nanoparticles was 2.5- and 1.8-fold higher for the drug solubilized and suspended solid lipid nanoparticle formulation, respectively, when compared to the celecoxib reference. A significant difference was observed between the plasma concentration-time profiles and pharmacokinetic parameters for the three investigated formulations. Finally, this investigation displayed promising outcomes that both solubilized and suspended celecoxib in the lipid core of the solid lipid nanoparticles offers the potential to improve the compound's oral bioavailability and thereby reduce the dosing frequency.

Improved oral bioavailability of poorly water-soluble vorinostat by self-microemulsifying drug delivery system

Background

Vorinostat is a histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) with anticancer properties. However, it is plagued by low water solubility, low permeability (BCS class IV drug), and suboptimal pharmacokinetics. The purpose of the present study was to develop a self-microemulsifying drug delivery system (SMEDDS) to enhance the oral bioavailability of vorinostat. Capryol 90, labrasol, and polyethylene glycol (PEG 400) were selected as oil phase, surfactant, and co-surfactant, respectively. The vorinostat self-microemulsifying drug delivery systems were tested for self-microemulsifying time, phase separation, effect of pH, droplet size, zeta potential, dilution study, Fourier-transform infrared (FT-IR) spectroscopy analysis, and field emission scanning electron microscopy (FESEM). A rat model in vivo pharmacokinetic study was conducted for the optimized formulation against vorinostat pure drug powder.

Results

The results from the characterization studies showed that the optimized formulation (F7) self-microemulsification time was 1.4 ± 0.05 min and no precipitation or phase separation was observed. The mean droplet size, polydispersity index (PDI), and zeta potential of the optimized formulation (F7) were found to be 272.9 ± 82.7 nm, 0.415, and − 57.2 mV, respectively. The pharmacokinetic parameters of the optimized formulation (F7) showed a 1.6-fold increase in maximum concentration (Cmax) and a 3.6-fold increase in area under the curve (AUC(0−∞)), in comparison with pure drug in suspension.

Conclusions

The findings suggest that SMEDDS formulation could be an effective method for increasing the oral bioavailability of vorinostat, which is poorly water soluble.

Novel treatment for refractory rheumatoid arthritis with total glucosides of paeony and nobiletin codelivered in a self-nanoemulsifying drug delivery system

Patients with refractory rheumatoid arthritis (RA) remain a substantial clinical problem, while the overexpression of P-glycoprotein (P-gp) on their lymphocytes may contribute to resistance to anti-rheumatic drugs. This study aims to develop a novel treatment for refractory RA consisting of the combination of total glucosides of paeony (TGPs) and the P-gp inhibitor nobiletin (N), which are codelivered in a self-nanoemulsifying drug delivery system (SNEDDS). Based on the solubility, compatibility, and pseudoternary phase diagram tests, a nano-SNEDDS formulation composed of capryol 90-cremophor EL35-tcranscutol HP (CET) to codeliver TGP and N was developed, and this formulation increased the bioavailability of TGP by 435.04% (indicated with paeoniflorin). A modified adjuvant-induced arthritis (AIA) rat model was verified for the overexpression of P-gp in lymphocytes and resistance to methotrexate (MTX) treatment at the reported anti-inflammatory dosage. CET formulation not only increased the solubility and permeability of TGP but also inhibited the function and expression of P-gp, leading to enhanced bioavailability and intracellular concentration in the lymphocytes of AIA rats and consequently boosting the anti-arthritic effects of TGP. Moreover, TGP and N coloaded CET reduced the expression of P-gp in AIA rats partly by inhibiting the phosphorylated AKT and HIF-1α pathways. In summary, TGP-N coloaded SNEDDS is a novel and effective treatment for refractory RA.

Design and Evaluation of Two-Step Biorelevant Dissolution Methods for Docetaxel Oral Formulations

Dissolution is a pivotal tool for oral formulations. Dissolution could be used to either reduce the risk of product failure through quality control or predict and understand in vivo performance of drug formulations. The latter is always challenging because multiple factors such as selection of media, gastrointestinal components, physiological factors, consideration of fasted and fed state are involved. Previously published dissolution methods such as one-step dissolution in individual simulated gastric fluid, simulated intestinal fluid, or phosphate buffer saline did not signify the realistic gastrointestinal transit effect. Docetaxel (DTX), a poorly water-soluble drug, is commercially available only as injectable dosage forms, and thus many publications studied the development of oral DTX formulations. In our previous report, we developed oral lipid-based DTX granules that showed higher oral absorption in rats compared to DTX powder. However, one-step dissolution in simulated gastric fluid showed no difference between DTX granules and DTX powder. Therefore, the present study aimed to develop new two-step biorelevant dissolution methods for DTX oral formulations. In the study, new two-step biorelevant dissolution methods in fasted or fed states with pancreatin were developed and compared with other previously reported dissolution methods. The new two-step biorelevant dissolution methods successfully discriminated the difference of dissolution between DTX granules and DTX powder, which reflected the in vivo difference of absorption of these two formulations. Moreover, food effects were confirmed for DTX. The new dissolution methods have the potential to be used to predict and understand in vivo performance of oral solid dosage forms.

Design and Optimization of Pioglitazone Hydrochloride Self-Nanoemulsifying Drug Delivery System (SNEDDS) Incorporated into an Orally Disintegrating Tablet

Pioglitazone Hydrochloride (PGZ) suffers from poor aqueous solubility. The aim of this research was to design orally disintegrating tablets with self-nanoemulsifying properties (T-SNEDDS) to improve the Pioglitazone solubility and dissolution rate. Three liquid self-nanoemulsifying systems (L-SNEDDS) were formulated and evaluated for transmittance percentage, emulsification time, particle size, Poly dispersity index (PDI), percentage of content, solubility and stability. The optimum L-SNEDDS formula was converted to a solidified self-nanoemulsifying drug delivery system (S-SNEDDS) by adsorption on Syloid (SYL). Powder characterization tests, such as flowability tests, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM), were performed for the selected S-SNEDDS formulation. Orally disintegrating tablets (ODT) were formulated by blending S-SNEDDS with tableting excipients. The ODT tablet batch composed of Prosolv was selected for tablet quality control tests, such as hardness, friability, disintegration time, content uniformity, weight variation, in vitro release, in vivo studies and accelerated stability studies. ODT tablets showed accepted mechanical properties and rapid disintegration time (<30 s). No drug degradation was observed at 3 months into the accelerated stability study. The optimized L-SNEDDS, S-SNEDDS and ODT (T-SNEDDS), showed significant enhancement of PGZ in vitro dissolution profiles compared to the pure drug (p > 0.05). In vivo pharmacokinetic and pharmacodynamic evaluation of ODTs showed better behavior compared to the raw drug suspension and the commercial tablet (p > 0.05). Orally disintegrating tablets revealed a promising potential to improve Pioglitazone poor aqueous solubility, dissolution profile and bioavailability.

Synthesis and Characterization of Carboxymethyl Chitosan Nanosponges with Cyclodextrin Blends for Drug Solubility Improvement

This study aimed to enhance the solubility and release characteristics of docetaxel by synthesizing highly porous and stimuli responsive nanosponges, a nano-version of hydrogels with the additional qualities of both hydrogels and nano-systems. Nanosponges were prepared by the free radical polymerization technique and characterized by their solubilization efficiency, swelling studies, sol-gel studies, percentage entrapment efficiency, drug loading, FTIR, PXRD, TGA, DSC, SEM, zeta sizer and in vitro dissolution studies. In vivo toxicity study was conducted to assess the safety of the oral administration of prepared nanosponges. FTIR, TGA and DSC studies confirmed the successful grafting of components into the stable nano-polymeric network. A porous and sponge-like structure was visualized through SEM images. The particle size of the optimized formulation was observed in the range of 195 ± 3 nm. The fabricated nanosponges noticeably enhanced the drug loading and solubilization efficiency of docetaxel in aqueous media. The drug release of fabricated nanosponges was significantly higher at pH 6.8 as compared to pH 1.2 and 4.5. An acute oral toxicity study endorsed the safety of the system. Due to an efficient preparation technique, as well as its enhanced solubility, excellent physicochemical properties, improved dissolution and non-toxic nature, nanosponges could be an efficient and a promising approach for the oral delivery of poorly soluble drugs.

Enhanced Oral Bioavailability of Epalrestat SBE7-β-CD Complex Loaded Chitosan Nanoparticles: Preparation, Characterization and in-vivo Pharmacokinetic Evaluation

Background

Epalrestat (EPL) is a carboxylic acid derivative with poor aqueous solubility and its pharmacokinetic features are not fully defined.

Purpose

Current research aimed to fabricate inclusion complexation of EPL with SBE₇ β-CD (IC) and EPL/SBE₇ β-CD CS NPs (NP).

Methods

EPL was complexed with SBE₇ β-CD using the co-precipitation method, and the prepared complex was fabricated into nanoparticles using the ionic gelation method. The prepared formulations were characterized for particle size analysis, surface morphology, and in vitro dissolution study. The % inhibition of EPL against α-glucosidase enzyme was also conducted to check the drug’s antidiabetic activity. Finally, an in vivo pharmacokinetic investigation was carried out to determine the concentration of EPL in rabbit plasma of the prepared formulation. In vivo pharmacokinetic studies were conducted by giving a single dose of pure EPL, IC, and NP.

Results

The size of NP was found to be 241.5 nm with PDI 0.363 and zeta potential of +31.8 mV. The surface of the prepared NP was non-porous, smooth and spherical when compared with pure EPL, SBE₇ β-CD and IC. The cumulative drug release (%) from IC and NP was 73% and 88%, respectively, as compared to pure drug (25%). The % inhibition results for in vitro α-glucosidase was reported to be 74.1% and the predicted binding energy for in silico molecular docking was calculated to be −6.6 kcal/mol. The calculated C_max values for EPL, IC and NP were 4.75±3.64, 66.91±7.58 and 84.27±6.91 μg/mL, respectively. The elimination half-life of EPL was 4 h and reduced to 2 h for IC and NP. The AUC_0-α for EPL, IC and NP were 191.5±164.63, 1054.23±161.77 and 1072.5±159.54 μg/mL*h, respectively.

Conclusion

Taking these parameters into consideration it can be concluded that IC and NP have prospective applications for greatly improved delivery and regulatedt release of poorly water soluble drugs, potentially leading to increase therapeutic efficacy and fewer side effects.

Extra virgin olive oil-based phospholipid complex/self-microemulsion enhances oral absorption of salvianolic acid B through inhibition of catechol-O-methyltransferase-mediated metabolism

The oral bioavailability of many phenolic acid drugs is severely limited due to the high hydrophilicity and extensive first-pass effect induced by catechol-O-methyltransferase (COMT) metabolism. The present study investigated the inhibitory activity of the pharmaceutical excipients of extra virgin olive oil (EVOO) against COMT and evaluated the potential of a self-microemulsion loaded with a phospholipid complex containing EVOO for oral absorption enhancement of salvianolic acid B (SAB), a model phenolic acid. In vitro COMT assay showed that EVOO could effectively inhibit enzyme activity in the rat liver cytosol. Next, the SAB phospholipid complex/self-microemulsion containing EVOO (named SP-SME1) was prepared and characterized (particle size, 243.60 ± 6.96 nm and zeta potential, -23.67 ± -1.36 mV). The phospholipid complex/self-microemulsion containing ethyl oleate (EO) (named SP-SME2) was taken as the control group. Compared with free SAB, the apparent permeability coefficient (P_app value) of the two SP-SMEs significantly increased (12.0-fold and 10.90-fold). Pharmacokinetic study demonstrated that the AUC_0-∞ value of SAB for the SP-SME1 group significantly increased by 4.72 and 2.82 times compared to those for free SAB (p < 0.001) and SP-SME2 (p < 0.01), respectively. Moreover, the AUC_0-∞ value of monomethyl-SAB (metabolite of SAB, MMS) for the SP-SME1 group decreased by 0.83 times compared to that for SP-SME2. In conclusion, the EVOO-based phospholipid complex/self-microemulsion greatly enhanced the oral absorption of SAB, which was mainly attributed to the inhibition of COMT activity induced by EVOO.

Ultrasonic-assisted preparation of eucalyptus oil nanoemulsion: Process optimization, in vitro digestive stability, and anti-Escherichia coli activity

Eucalyptus oil (EO) is a natural and effective antimicrobial agent; however, it has disadvantages such as poor water solubility and instability. The aim of this study was to investigate the effect of process vessels and preparation process parameters on the particle size of the emulsion droplets using ultrasonic technique and response surface methodology to prepare eucalyptus oil nanoemulsion (EONE). The optimal sonication process parameters in conical centrifuge tubes were confirmed: sonication distance of 0.9 cm, sonication amplitude of 18%, and sonication time of 2 min. Under these conditions, the particle size of EONE was 18.96 ± 4.66 nm, the polydispersity index was 0.39 ± 0.09, and the zeta potential was -31.17 ± 2.15 mV. In addition, the changes in particle size, potential, micromorphology, and anti-Escherichia coli activity of EONE during digestion were investigated by in vitro simulated digestion. The emulsion was stable in simulated salivary fluid, tended to aggregate in simulated gastric fluid, and increased in particle size and potential value in simulated intestinal fluid. EONE showed higher anti-E. coli activity than EO by simulated digestion. These results provide a useful reference for the in vivo antimicrobial application of the essential oil.

Dual-modified PCL-PEG nanoparticles for improved targeting and therapeutic efficacy of docetaxel against colorectal cancer

Polycaprolactone-poly (ethylene glycol) block copolymer (PCL-PEG) based nanoparticles were prepared for the intravenous administration of docetaxel (DTX). PCL-PEG-Tyr and PCL-PEG-Ang were synthesized by using tyrosine (Tyr) and angiopep-2 (Ang) as coupling ligands, and dual-modified PCL-PEG-based nanoparticles (PCL-PEG-Tyr/Ang) were prepared. The physicochemical properties, in vitro drug release, in vitro cytotoxicity, in vitro cellular uptake efficiency, in vivo biodistribution and in vivo antitumor efficacy of PCL-PEG-based nanoparticles were investigated. The PCL-PEG-based nanoparticles were spherical with a mean diameter of 100 nm and high encapsulation efficiencies (> 85%). The results of in vitro drug release showed that the PCL-PEG-based nanoparticles loaded with DTX had sustained-release characteristics. For in vitro cytotoxicity tests, the dual-modified PCL-PEG-based nanoparticles (PCL-PEG-Tyr/Ang) demonstrated the minimum IC50 value (2.94 µg/mL) compared with other PCL-PEG-based nanoparticles. In addition, the cellular uptake of coumarin-6 (C6) in HT29 cells was observed and determined in the PCL-PEG-Tyr/Ang nanoparticles group, which was significantly higher than that in the other PCL-PEG-based groups and C6 solution group. The results of in vivo imaging showed that dual-modified PCL-PEG nanoparticles had better tumor targeting than the other PCL-PEG-based nanoparticles. In the HT29 tumor-xenografted nude mice model, DTX-loaded PCL-PEG-Tyr/Ang nanoparticles also had a significantly higher inhibitory efficacy on tumor growth than Taxotere®-treated group. These results indicated that the dual-modified PCL-PEG-based nanoparticles (PCL-PEG-Tyr/Ang) could be a promising anticancer drug delivery system.

Probing the new strategy for the oral formulations of taxanes: changing the method with the situation

The first-generation taxanes (including paclitaxel and docetaxel) are widely used for the treatment of various cancers in clinical settings. In the past decade, a series of new-generation taxanes have been developed which are effective in the inhibition of tumor resistance. However, intravenous (i.v.) infusion is still the only route of administration, and may result in serious adverse reactions with respect to the utilization of Cremophor EL or Tween-80 as solvent. Besides, the dosing schedule is also limited. Therefore, oral administration of taxanes is urgently needed to avoid the adverse reactionss and increase dosing frequency. In this review, we first outlined the discovery and development of taxane-based anticancer agents. Furthermore, we summarized the research progress on the oral formulations of taxanes and proposed some thoughts on the future development of oral taxane formulations.

Development and in vitro and in vivo evaluations of a microemulsion formulation for the oral delivery of oxaprozin

BACKGROUND

Oxaprozin is labeled as a Class II drug in the biopharmaceutical classification system, and its poor solubility in the entire gastrointestinal tract may be the main reason for its poor oral absorption capacity.

OBJECTIVE

The purpose of this study was to develop an oxaprozin formulation to enhance its oral absorption.

METHOD

Oxaprozin-loaded microemulsions were prepared using the titration method and pseudoternary phase diagram. Characterization experiments were performed on microemulsion preparations, including pH, particle size, shape, zeta potential and stability (thermodynamic, dilution, and differential scanning calorimetry). Then, the in vitro release of the microemulsion and in vivo pharmacokinetics in rats were evaluated.

RESULTS

Several microemulsion formulations were prepared. The optimal formulation was 15% oleoyl macrogolglycerides, 35% Tween 20/isopropanol (Km=2) and 50% distilled water. Its particle size met the requirements, and it had a spherical shape with a negatively charged surface. This microemulsion-loaded drug was applied to in vitro release and in vivo pharmacokinetic experiments at 7.47 mg/mL. In vitro release of the oxaprozin-loaded microemulsion best fit the first-order model, while the microemulsion preparation had a certain sustained release effect. In vivo pharmacokinetic experiments indicated that the microemulsion formulation significantly delayed the peak time of the blood concentration and simultaneously prolonged the half-life of drug elimination.

CONCLUSION

The obtained data revealed satisfactory results for this novel microemulsion of oxaprozin, which is very meaningful for clinical trials.

Quality-by-Design-Based Development of a Voxelotor Self-Nanoemulsifying Drug-Delivery System with Improved Biopharmaceutical Attributes

Low aqueous solubility and poor oral bioavailability are limiting factors in the oral delivery of voxelotor, an antisickling agent. To overcome these limitations, a voxelotor self-nanoemulsifying drug delivery system was developed. Various oils, surfactants, and cosurfactants were screened for their solubilization potential for the drug. The area of nanoemulsification was identified using a ternary phase diagram. An experimental mixture design and a desirability function were applied to select SNEDDSs that contain a maximum amount of lipids and a minimum amount of surfactant, and that possess optimal emulsification properties (i.e., droplet sizes, polydispersity index (PDI), emulsification time, and transmittance percentage). The optimized SNEDDS formulation was evaluated for the self-emulsifying time (32 s), droplet size (35 nm), and zeta potential (−8 mV). In vitro dissolution studies indicated a 3.1-fold improvement in drug solubility from the optimized SNEDDS over pure drug powder. After 60 min of in vitro lipolysis, 88% of the voxelotor loaded in the SNEDDS remained in the aqueous phase. Cytotoxicity evaluation, using Caco-2 cells, indicated the safety of the formulation at 0.9 mg/mL. The transport of the voxelotor SNEDDS across Caco-2 monolayers was significantly enhanced compared to that of the free drug. Compared to the drug suspension, the developed SNEDDS enhanced the oral bioavailability (1.7-fold) of voxelotor in rats. The results suggest that further development of SNEDDSs for the oral delivery of voxelotor is needed.

Recent Advances in Herbal Nanomedicines for Cancer Treatment

Cancer continues to be one of the deadliest diseases that adversely impacts the large population of the world. A stack of scientific documents reflects a huge number of potent plant-based anticancer drugs such as curcumin (CUR), podophyllotoxin, camptothecin (CPT), vincristine, vinblastine, paclitaxel (PTX), etc. that have been integrated into the modern practice of cancer treatment. The demand for natural products raises exponentially as they are generally considered to be safe, and devoid of critical toxic effects at the therapeutic dose when compared to their synthetic counterparts. Despite rising interest towards the potent phytoconstituents, formulation developer faces various challenges in drug development processes such as poor water solubility, low bioavailability, marginal permeability, and nonspecific drug delivery at the target site, etc. Further, adverse drug reaction and multidrug resistance are other critical issues that need to be addressed. Nanomedicines owing to their unique structural and functional attributes help to fix the above challenges for improved translational outcomes. This review summarises the prospects and challenges of a nanotechnology-based drug delivery approach for the delivery of plant-based anticancer drugs.

Enhancement of Docetaxel Absorption Using Ritonavir in an Oral Milk-Based Formulation

OBJECTIVE

The current study aimed to develop a novel milk-based formulation of docetaxel, a sparingly soluble antineoplastic agent, administered so far exclusively by the intravenous route and evaluate its oral bioavailability.

METHODS

Pre-formulation studies included the determination of docetaxel solubility in water-alcohol mixtures as well as short-term content uniformity experiments of the final formulation. The pharmacokinetic (PK) performance of the developed milk-based formulations was further evaluated in vivo in mice using ritonavir, a potent P-glycoprotein inhibitor, as an absorption enhancer of docetaxel and the marketed intravenous docetaxel formulation, Taxotere®, as a control.

RESULTS

In vivo PK results in mice showed that all the administered oral docetaxel formulations had limited absorption in the absence of ritonavir. On the contrary, ritonavir co-administration given as pre-treatment significantly enhanced oral bioavailability of both the marketed and milk-based docetaxel formulations; an even more marked increase in drug exposure was observed when ritonavir was incorporated within the docetaxel milk-based formulation. The fixed-dose combination also showed a more prolonged absorption of the drug compared to separate administrations.

CONCLUSIONS

The current study provides insights for the discovery of a novel milk-based formulation that could potentially serve as an alternative, non-toxic and patient-friendly carrier for an acceptable docetaxel oral chemotherapy.

Solubility Enhancement of Ibuprofen by Adsorption onto Spherical Porous Calcium Silicate

The solubility of a drug is higher when it is in an amorphous form than when it is in a crystalline form. To enhance the solubility of ibuprofen (IBU), a poorly water-soluble drug, we attempted to adsorb IBU onto spherical porous calcium silicate (Florite^® PS300, PS300) in two ways: the evaporation (EV) and sealed heating (SH) methods. The crystallinity of the samples was evaluated using powder X-ray diffraction analysis (PXRD) and differential scanning calorimetry (DSC). The molecular interaction between IBU and PS300 was evaluated with FTIR. In addition, the dissolution behavior of IBU in the samples was assessed by the dissolution test. Based on the results of the PXRD and DSC measurements, both methods allowed adsorption of IBU onto PS300, and IBU was amorphized. Based on the FTIR observations, in the SH or EV mixtures containing 10% and 30% IBU, respectively, it seemed that the IBU molecules intermolecularly interacted with calcium molecules as the main component of PS300. Improvement in the solubility of IBU was observed with both methods; however, the dissolution rate of IBU from samples prepared via SH was higher than that from EV, or of IBU crystals. Collectively, our findings indicate that the petal-like structure of PS300, which has a spherical shape and good flowability, is an effective tool for adsorbing IBU onto PS300 via SH.

Nanoemulsion for Improving the Oral Bioavailability of Hesperetin: Formulation Optimization and Absorption Mechanism

This study aimed to prepare a nanoemulsion vehicle to improve the oral bioavailability of hesperetin. The pseudo-ternary phase diagrams and the RSM were used to optimize nanoemulsion parameters. Compared with hesperetin suspension, the AUC_0-t and C_max of nanoemulsion were increased by 5.67-fold and 2.64-fold, respectively. The proportion of lymphatic transport reached 87.72%, the cumulative absorption amount of jejunum, ileum, and duodenum increased by 1.1-fold, 1.92-fold, and 1.5-fold, respectively. The results implied that hesperetin nanoemulsion could effectively improve the bioavailability of hesperetin by increasing lymphatic transport and enhancing intestinal permeability. Therefore, nanoemulsion is a potential method to improve the bioavailability of hesperetin, which has strong practicability.

Microemulsion-Based Media in Nose-to-Brain Drug Delivery

Nose-to-brain drug delivery has recently attracted enormous attention as an alternative to other delivery routes, including the most popular oral one. Due to the unique anatomical features of the nasal cavity, drugs administered intranasally can be delivered directly to the central nervous system. The most important advantage of this approach is the ability to avoid the blood-brain barrier surrounding the brain and blocking the entry of exogenous substances to the central nervous system. Moreover, selective brain targeting could possibly avoid peripheral side effects of pharmacotherapy. The challenges associated with nose-to-brain drug delivery are mostly due to the small volume of the nasal cavity and insufficient drug absorption from nasal mucosa. These issues could be minimized by using a properly designed drug carrier. Microemulsions as potential drug delivery systems offer good solubilizing properties and the ability to enhance drug permeation through biological membranes. The aim of this review is to summarize the current status of the research focused on microemulsion-based systems for nose-to-brain delivery with special attention to the most extensively investigated neurological and psychiatric conditions, such as neurodegenerative diseases, epilepsy, and schizophrenia.

Natural product-based nanoformulations for cancer therapy: Opportunities and challenges

Application of natural product-based nanoformulations for the treatment of different human diseases, such as cancer, is an emerging field. The conventional cancer therapeutic modalities, including surgery, chemotherapy, immunotherapy, radiotherapy has limited achievements. A larger number of drawbacks are associated with these therapies, including damage to proliferating healthy tissues, structural deformities, systemic toxicity, long-term side effects, resistance to the drug by tumor cells, and psychological problems. The advent of nanotechnology in cancer therapeutics is recent; however, it has progressed and transformed the field of cancer treatment at a rapid rate. Nanotherapeutics have promisingly overcome the limitations of conventional drug delivery system, i.e., low aqueous solubility, low bioavailability, multidrug resistance, and non-specificity. Specifically, natural product-based nanoformulations are being intentionally studied in different model systems. Where it is found that these nanoformulations has more proximity and reduced side effects. The nanoparticles can specifically target tumor cells, enhancing the specificity and efficacy of cancer therapeutic modalities which in turn improves patient response and survival. The integration of phytotherapy and nanotechnology in the clinical setting may improve pharmacological response and better clinical outcome of patients.

Tailoring functional nanostructured lipid carriers for glioblastoma treatment with enhanced permeability through in-vitro 3D BBB/BBTB models

The blood-brain barrier (BBB) and blood-brain tumour barrier (BBTB) pose a significant challenge to drug delivery to brain tumours, including aggressive glioblastoma (GB). The present study rationally designed functional nanostructured lipid carriers (NLC) to tailor their BBB penetrating properties with high encapsulation of CNS negative chemotherapeutic drug docetaxel (DTX). We investigated the effect of four liquid lipids, propylene glycol monolaurate (Lauroglycol® 90), Capryol® propylene glycol monocaprylate, caprylocaproylmacrogol-8-glycerides (Labrasol®) and polyoxyl-15-hydroxystearate (Kolliphor® HS15) individually and in combination to develop NLCs with effective permeation across in-vitro 3D BBB model without alteration in the integrity of the barrier. With desirable spherical shape as revealed by TEM and an average particle size of 123.3 ± 0.642 nm and zeta potential of -32 mV, DTX-NLCs demonstrated excellent stability for six months in its freeze-dried form. The confocal microscopy along with flow cytometry data revealed higher internalisation of DTX-NLCs in U87MG over SVG P12 cells. Micropinocytosis was observed to be one of the dominant pathways for internalisation in U87MG cells while clathrin-mediated pathway was more predominat in patient-derived glioblastoma cells. The NLCs readily penetrated the actively proliferating peripheral cells on the surface of the 3D tumour spheroids as compared to the necrotic core. The DTX-NLCs induced cell arrest through G2/M phase with a significant decrease in the mitochondrial reserve capacity of cells. The NLCs circumvented BBTB with high permeability followed by accumulation in glioblastoma cells with patient-derived cells displaying ~2.4-fold higher uptake in comparison to U87MG when studied in a 3D in-vitro model of BBTB/GB. We envisage this simple and industrially feasible technology as a potential candidate to be developed as GB nanomedicine.

Self-Nano-Emulsifying Drug-Delivery Systems: From the Development to the Current Applications and Challenges in Oral Drug Delivery

Approximately one third of newly discovered drug molecules show insufficient water solubility and therefore low oral bio-availability. Self-nano-emulsifying drug-delivery systems (SNEDDSs) are one of the emerging strategies developed to tackle the issues associated with their oral delivery. SNEDDSs are composed of an oil phase, surfactant, and cosurfactant or cosolvent. SNEDDSs characteristics, their ability to dissolve a drug, and in vivo considerations are determinant factors in the choice of SNEDDSs excipients. A SNEDDS formulation can be optimized through phase diagram approach or statistical design of experiments. The characterization of SNEDDSs includes multiple orthogonal methods required to fully control SNEDDS manufacture, stability, and biological fate. Encapsulating a drug in SNEDDSs can lead to increased solubilization, stability in the gastro-intestinal tract, and absorption, resulting in enhanced bio-availability. The transformation of liquid SNEDDSs into solid dosage forms has been shown to increase the stability and patient compliance. Supersaturated, mucus-permeating, and targeted SNEDDSs can be developed to increase efficacy and patient compliance. Self-emulsification approach has been successful in oral drug delivery. The present review gives an insight of SNEDDSs for the oral administration of both lipophilic and hydrophilic compounds from the experimental bench to marketed products.

Drug-interactive mPEG-b-PLA-Phe(Boc) micelles enhance the tolerance and anti-tumor efficacy of docetaxel

Docetaxel (DTX) is one of the most promising chemotherapeutic agents for a variety of solid tumors. However, the clinical efficacy of the marketed formulation, Taxotere^®, is limited due to its poor aqueous solubility, side effects caused by the emulsifier, and low selective DTX distribution in vivo. Here a facile, well-defined, and easy-to-scale up DTX-loaded N-(tert-butoxycarbonyl)-_L-phenylalanine end-capped methoxy-poly(ethylene glycol)-block-poly(_D,L-lactide) (mPEG-b-PLA-Phe(Boc)) micelles (DTX-PMs) were prepared in an effort to develop a less toxic and more efficacious docetaxel formulation. The physicochemical properties, pharmacokinetics, biodistribution, and in vivo anti-tumor efficacy were evaluated in comparison to the marketed DTX formulation Taxotere^®. DTX was successfully encapsulated in the hydrophobic micellar core with a high encapsulation efficiency (> 95%) and a high drug loading capacity (4.81 ± 0.08%). DTX-PMs exhibited outstanding stability in the aqueous environment due to the strong interactions between the terminal amino acid residues and docetaxel. The pharmacokinetic study in Sprague–Dawley rats revealed higher DTX concentrations in both whole blood and plasma for the group treated with DTX-PMs than that treated with Taxotere^® due to the improved stability of the micellar formulation. In human non-small cell lung cancer (A549) tumor-bearing Balb/c nude mice, DTX-PMs significantly improved DTX accumulation and stalled DTX elimination in tumors than in bone marrow. Furthermore, only by half of the DTX dosage, our DTX/mPEG-b-PLA-Phe(Boc) micelles can achieve similar therapeutic effects as Taxotere^®. Altogether, DTX-PMs hold great promise as a simple and effective drug delivery system for cancer chemotherapy.

Acute regulation of apical ABC transporters in the gut. Potential influence on drug bioavailability

The extensive intestinal surface offers an advantage regarding nutrient, ion and water absorptive capacity but also brings along a high exposition to xenobiotics, including drugs of therapeutic use and food contaminants. After absorption of these compounds by the enterocytes, apical ABC transporters play a key role in secreting them back to the intestinal lumen, hence acting as a transcellular barrier. Rapid and reversible modulation of their activity is a subject of increasing interest for pharmacologists. On the one hand, a decrease in transporter activity may result in increased absorption of therapeutic agents given orally. On the other hand, an increase in transporter activity would decrease their absorption and therapeutic efficacy. Although of less relevance, apical ABC transporters also contribute to disposition of drugs systemically administered. This review article summarizes the present knowledge on the mechanisms aimed to rapidly regulate the activity of the main apical ABC transporters of the gut: multidrug resistance protein 1 (MDR1), multidrug resistance-associated protein 2 (MRP2) and breast cancer resistance protein (BCRP). Regulation of these mechanisms by drugs, drug delivery systems, drug excipients and nutritional components are particularly considered. This information could provide the basis for controlled regulation of bioavailability of therapeutic agents and at the same time would help to prevent potential drug-drug interactions.

Biosurfactants as a Novel Additive in Pharmaceutical Formulations: Current Trends and Future Implications

BACKGROUND

Surfactants are an important category of additives that are used widely in most of the formulations as solubilizers, stabilizers, and emulsifiers. Current drug delivery systems comprise of numerous synthetic surfactants (such as Cremophor EL, polysorbate 80, Transcutol-P), which are associated with several side effects though used in many formulations. Therefore, to attenuate the problems associated with conventional surfactants, a new generation of surface-active agents is obtained from the metabolites of fungi, yeast, and bacteria, which are termed as biosurfactants.

OBJECTIVES

In this article, we critically analyze the different types of biosurfactants, their origin along with their chemical and physical properties, advantages, drawbacks, regulatory status, and detailed pharmaceutical applications.

METHODS

243 papers were reviewed and included in this review.

RESULTS

Briefly, Biosurfactants are classified as glycolipids, rhamnolipids, sophorolipids, trehalolipids, surfactin, lipopeptides & lipoproteins, lichenysin, fatty acids, phospholipids, and polymeric biosurfactants. These are amphiphilic biomolecules with lipophilic and hydrophilic ends and are used as drug delivery vehicles (foaming, solubilizer, detergent, and emulsifier) in the pharmaceutical industry. Despite additives, they have some biological activity as well (anti-cancer, anti-viral, anti-microbial, P-gp inhibition, etc.). These biomolecules possess better safety profiles and are biocompatible, biodegradable, and specific at different temperatures.

CONCLUSION

Biosurfactants exhibit good biomedicine and additive properties that can be used in developing novel drug delivery systems. However, more research should be driven due to the lack of comprehensive toxicity testing and high production cost which limits their use.

Bicontinuous microemulsions containing Melaleuca alternifolia essential oil as a therapeutic agent for cutaneous wound healing

The Melaleuca alternifolia essential oil (MEO) has been widely used due to its healing and antimicrobial action. Its incorporation into drug delivery systems is a reality, and numerous studies have already been developed for this purpose. In this regard, the aim of this work was to develop, characterize, and evaluate the in vivo pharmacological activity of bicontinuous microemulsions (BME) containing MEO. Through diagram construction, a formulation consisting of Kolliphor® HS 15 (31.05%), Span® 80 (3.45%), isopropyl myristate (34.5%), and distilled water (31%) was selected and MEO was incorporated in the proportion of 3.45% (v/v). Morphological analysis characterization confirms that the system studied herein is a BME. The evaluated formulation showed physicochemical characteristics that allow its topical use. Rheologically, samples were characterized as pseudo-plastic non-Newtonian thixotropic fluids. The chromatographic method developed is in accordance with the current recommendations. The extraction method used assured a 100% recovery of the pharmacological marker (terpinen-4-ol). In vivo studies suggest that BME loaded with MEO may contribute to the healing process of skin wounds. In addition, it demonstrated antibacterial activity for Gram-positive and Gram-negative bacteria. Therefore, the BME system loaded with MEO is promising as a healing and antimicrobial agent for skin wounds.Graphical abstract.

In Vitro Evaluation of a Fluorescent Microemulsion as an Oral Delivery Carrier and its Potential Application in Tracking Bioactive Compounds Label-Free

In this work, a microemulsion emitting fluorescence was fabricated as a potential oral delivery system for bioactive compounds. In simulated oral administration, the microemulsion was characterized for its microstructure by ¹hydrogen-nuclear magnetic resonance (¹H-NMR). Results showed that microemulsions not only have good resistance to oral and gastric phases, but also lay a solid foundation for the release of bioactive compounds in the intestine. Fluorescence stability tests showed that microemulsions exhibit a remarkable fluorescence intensity in the digestive environment, indicating feasibility as a label-free delivery carrier. Moreover, in vitro release tests of bioactive compounds confirmed that an α-linolenic acid (ALA)-loaded microemulsion mainly released in the intestine, thereby achieving the aim of controlling the release of bioactive compounds. These results suggest that the synthesized fluorescent microemulsion, combining the favorable features of nontoxicity, antidigestive stability, remarkable fluorescence intensity, and controllable release, can be regarded as a promising label-free delivery carrier for oral administration.

Formulation of a Phenol-Rich Extract from Unripe Olives (Olea europaea L.) in Microemulsion to Improve Its Solubility and Intestinal Permeability

The beneficial properties of phenolic compounds from Olea europaea L. are well-known. An olive extract (OE) was prepared from unripe olives (Moraiolo cultivar). The study aimed to formulate OE into a microemulsion (ME) in oral dosage form. OE was extracted from olives with EtOH:H₂O (80:20) and characterized by HPLC-DAD. ME composition was stated by a solubility and pseudo-ternary diagram. The ME was chemically and physically characterized, and its stability at 4 °C was analyzed for three months. The ability of the formulation to ameliorate the solubility and the intestinal permeability of OE was evaluated by a Parallel Artificial Membrane Permeability Assay (PAMPA) assay and Caco-2 cells. The total phenolic content of the extract was 39% w/w. The main constituent was oleuropein (31.0%), together with ligstroside (3.1%) and verbascoside (2.4%). The ME was prepared using Capryol 90 as the oily phase, and Cremophor EL and Transcutol (2:1) as surfactant and co-surfactant, respectively. ME droplet size was 14.03 ± 1.36 nm, PdI 0.20 ± 0.08, ζ-potential −1.16 ± 0.48. Stability of ME was confirmed for at least three months. The formulation was loaded with 35 mg/mL of OE, increasing the solubility of the extract by about four times. The enhanced permeability of OE was evaluated by PAMPA, as demonstrated by the Pe value (1.44 ± 0.83 × 10⁻⁶ cm/s for OE hydroalcoholic solution, 3.74 ± 0.34 × 10⁻⁶ cm/s for OE-ME). Caco-2 cell transport studies confirmed the same results: P_app was 16.14 ± 0.05 × 10⁻⁶ cm/s for OE solution and 26.99 ± 0.45 × 10⁻⁶ cm/s for OE-ME. ME proved to be a suitable formulation for oral delivery.

Development and Evaluation of Docetaxel-Phospholipid Complex Loaded Self-Microemulsifying Drug Delivery System: Optimization and In Vitro/Ex Vivo Studies

Docetaxel (DTX) has clinical efficacy in the treatment of breast cancer, but it is difficult to develop a product for oral administration, due to low solubility and permeability. This study focused on preparing a self-microemulsifying drug delivery system (SME) loaded with DTX-phospholipid complex (DTX@PLC), to improve the dissolution and gastrointestinal (GI) permeability of DTX. A dual technique combining the phospholipid complexation and SME formulation described as improving upon the disadvantages of DTX has been proposed. We hypothesized that the complexation of DTX with phospholipids can improve the lipophilicity of DTX, thereby increasing the affinity of the drug to the cell lipid membrane, and simultaneously improving permeability through the GI barrier. Meanwhile, DTX@PLC-loaded SME (DTX@PLC-SME) increases the dissolution and surface area of DTX by forming a microemulsion in the intestinal fluid, providing sufficient opportunity for the drug to contact the GI membrane. First, we prepared DTX@PLC-SME by combining dual technologies, which are advantages for oral absorption. Next, we optimized DTX@PLC-SME with nanosized droplets (117.1 nm), low precipitation (8.9%), and high solubility (33.0 mg/g), which formed a homogeneous microemulsion in the aqueous phase. Dissolution and cellular uptake studies demonstrated that DTX@PLC-SME showed 5.6-fold higher dissolution and 2.3-fold higher DTX uptake in Caco-2 cells than raw material. In addition, an ex vivo gut sac study confirmed that DTX@PLC-SME improved GI permeability of DTX by 2.6-fold compared to raw material. These results suggested that DTX@PLC-SME can significantly overcome the disadvantages of anticancer agents, such as low solubility and permeability.

Design and evaluation of self-nanoemulsifying drug delivery systems (SNEDDSs) for senicapoc

Senicapoc (SEN), a potent antisickling agent, shows poor water solubility and poor oral bioavailability. To improve the solubility and cell permeation of SEN, self-nanoemulsifying drug delivery systems (SNEDDSs) were developed. Capryol PGMC®, which showed the highest solubilization capacity, was selected as the oil. The self-emulsification ability of two surfactants, viz., Cremophor-EL® and Tween® 80, was compared. Based on a solubility study and ternary phase diagrams, three optimized nanoemulsions with droplet sizes less than 200 nm were prepared. An in vitro dissolution study demonstrated the superior performance of the SNEDDS over the free drug. During in vitro lipolysis, 80% of SEN loaded in the SNEDDS remained solubilized. An in vitro cytotoxicity study using the Caco-2 cell line indicated the safety of the formulations at 1 mg/mL. The transport of SEN-SNEDDSs across Caco-2 monolayers was enhanced 115-fold (p < 0.01) compared to that of the free drug. According to these results, SNEDDS formulations could be promising tools for the oral delivery of SEN.