Preparation and evaluation of novel mixed micelles as nanocarriers for intravenous delivery of propofol

Phyto-cosmeceutical gel containing curcumin and quercetin loaded mixed micelles for improved anti-oxidant and photoprotective activity

Ultra Violet radiations induced skin damage and associated skin disorders are a widespread concern. The consequences of sun exposure include a plethora of dermal conditions like aging, solar urticaria, albinism and cancer. Sunscreens provide effective protection to skin from these damages. Besides FDA approved physical and chemical UV filters, phytoconstituents with their multi functionalities are emerging as frontrunners in Therapy of skin disorders. Objective of this study was to develop novel phyto-dermal gel (PDG) with dual action of sun protection and antioxidant potential using polymeric mixed micelles (PMMs) are nanocarriers. PMMs of Pluronic F127 and Pluronic F68 loaded with curcumin and quercetin were optimized by 32 factorial designs. Responses studied were vesicle size, SPF, entrapment efficiency of curcumin and quercetin and antioxidant activity. Droplet size ranged from 300 to 500 nm with PDI in between 0.248 and 0.584. Combination of curcumin and quercetin showed enhanced sun protection and antioxidant activity. Pluronics played a significant positive role in various parameters. In present studies vesicle size of factorial batches was found to be between 387 and 527 nm, and SPF was found to be between 18.86 and 28.32. Transmission electron microscopy revealed spherical morphology of micelles. Optimized micelles were incorporated into Carbopol 940. Optimized PDG was evaluated for pH, drug content, spreadability, rheology, syneresis, ex vivo permeation, and skin retention. Hysteresis loop in the rheogram suggested thixotropy of PDG. Syneresis for gels from day 0-30 days was found to be between 0% and 12.46% w/w. SPF of optimized PDG was 27±0.5. Optimized PDG showed no signs of erythema and edema on Wistar rats. PMMs thus effectively enhanced antioxidant and skin protective effect of curcumin and quercetin.

Increasing the aqueous solubility of the anesthetic propofol through wormlike micelle formation

Propofol, a phenol derivative, is commonly employed as an intravenous anesthetic during clinical procedures, formulated as an oil/water emulsion due to its poor solubility in water. The stability limitations associated with emulsions have prompted research efforts towards developing aqueous formulations of propofol. In this work, we investigate the solubility enhancement of propofol in anionic and cationic surfactants. Our findings reveal that the solubility of propofol can increase significantly, up to 100-fold, depending on the nature of the micellar aggregate, as observed for alkylammonium halogenates CnTAB (for n = 12, 14 and 16), contrasting with the lower solubility with SDS. Interestingly, C14TAB and C16TAB demonstrate significantly higher solubility than C12TAB. This was attributed to the formation of wormlike micelles, in which the propofol molecules are positioned between the cationic heads of the surfactant molecules, changing the micellar curvature and the morphology of the aggregate. Therefore, the aromatic molecules in the micellar environment can be partitioned into the micellar cores and their palisades. Regarding C12TAB, the alkyl chain is too short to form wormlike micelles, thus, concentrating propofol molecules mainly into the micellar core, and consequently, leading to their aggregation. Solubility diagrams of propofol were constructed in conjunction with different surfactants. The systems exhibiting viscoelastic behavior, indicative of wormlike micelle formation, were further investigated using rheology. Additionally, the fluorescent properties of propofol enabled the examination of the anesthetic molecule within diverse micellar environments.

Dapsone-Loaded Mixed Micellar Gel for Treatment OF Acne Vulgaris

Mixed polymeric micelles are potential nanocarriers for topical drug delivery. Dapsone (DAP) is an antibacterial used as anti-acne agent, but challenged by low water solubility and poor skin permeability. In the present study, DAP-loaded mixed micellar gel was developed comprising Pluronics F-68 and F-127. Micelles were prepared by solvent evaporation method and particle size, ex vivo permeation, drug loading, and entrapment efficiency were determined. Central Composite Design was used to optimize formulation. Independent variables were concentration of Pluronics at three levels while micelle size and drug loading capacities were dependent variables. Droplet size ranged from 400 to 500 nm. Transmission electron microscopy revealed spherical morphology of micelles. Optimized micelles were incorporated into gel base using HPMC K100M, Sodium CMC, and Carbopol 980 as gelling agents. Gels were evaluated for pH, drug content, spreadability, rheology, syneresis, ex vivo permeation, and subacute dermal toxicity. Compared with solubility of free DAP (0.24+0.056 µg/ml), solubility in mixed micelles was 18.42±3.4 µg/ml in water at room temperature. Order of spreadability of gels was Na CMC < HPMC < Carbopol 980. Carbopol gels displayed thixotropy with index of 3.17. Syneresis for all gels from day 0 to day 30 was found to be in range of 4.2 to 15.6% w/w. Subacute dermal toxicity studies showed no signs of erythema and edema on rat skin until 21 days. These results suggest that mixed micelles can significantly increase solubility and permeability and sustain release of DAP and are suitable carriers for topical DAP delivery in anti-acne therapies.

Exploring the Application of Micellar Drug Delivery Systems in Cancer Nanomedicine

Various formulations of polymeric micelles, tiny spherical structures made of polymeric materials, are currently being investigated in preclinical and clinical settings for their potential as nanomedicines. They target specific tissues and prolong circulation in the body, making them promising cancer treatment options. This review focuses on the different types of polymeric materials available to synthesize micelles, as well as the different ways that micelles can be tailored to be responsive to different stimuli. The selection of stimuli-sensitive polymers used in micelle preparation is based on the specific conditions found in the tumor microenvironment. Additionally, clinical trends in using micelles to treat cancer are presented, including what happens to micelles after they are administered. Finally, various cancer drug delivery applications involving micelles are discussed along with their regulatory aspects and future outlooks. As part of this discussion, we will examine current research and development in this field. The challenges and barriers they may have to overcome before they can be widely adopted in clinics will also be discussed.

Transdermal delivery via medical device technologies

INTRODUCTION

Despite their effectiveness and indispensability, many drugs are poorly solvated in aqueous solutions. Over recent decades, the need for targeted drug delivery has led to the development of pharmaceutical formulations with enhanced lipid solubility to improve their delivery properties. Therefore, a dependable approach for administering lipid-soluble drugs needs to be developed.

AREAS COVERED

The advent of 3D printing or additive manufacturing (AM) has revolutionized the development of medical devices, which can effectively enable the delivery of lipophilic drugs to the targeted tissues. This review focuses on the use of microneedles and iontophoresis for transdermal drug delivery. Microneedle arrays, inkjet printing, and fused deposition modeling have emerged as valuable approaches for delivering several classes of drugs. In addition, iontophoresis has been successfully employed for the effective delivery of macromolecular drugs.

EXPERT OPINION

Microneedle arrays, inkjet printing, and fused deposition are potentially useful for many drug delivery applications; however, the clinical and commercial adoption rates of these technologies are relatively low. Additional efforts is needed to enable the pharmaceutical community to fully realize the benefits of these technologies.

Tunable Polymeric Mixed Micellar Nanoassemblies of Lutrol F127/Gelucire 44/14 for Oral Delivery of Praziquantel: A Promising Nanovector against Hymenolepis nana in Experimentally-Infected Rats

Hymenolepiasis represents a parasitic infection of common prevalence in pediatrics with intimidating impacts, particularly amongst immunocompromised patients. The present work aimed to snowball the curative outcomes of the current mainstay of hymenolepiasis chemotherapy, praziquantel (PRZ), through assembly of polymeric mixed micelles (PMMs). Such innovative nano-cargo could consolidate PRZ hydrosolubility, extend its circulation time and eventually upraise its bioavailability, thus accomplishing a nanoparadigm for hymenolepiasis tackling at lower dose levels. For consummating this goal, PRZ-PMMs were tailored via thin-film hydration technique integrating a binary system of Lutrol F127 and Gelucire 44/14. Box-Behnken design was planned for optimizing the nanoformulation variables employing Design-Expert^® software. Also, in Hymenolepis nana-infected rats, the pharmacodynamics of the optimal micellar formulation versus the analogous crude PRZ suspension were scrutinized on the 1st and 3rd days after administration of a single oral dose (12.5 or 25 mg/kg). Moreover, in vitro ovicidal activity of the monitored formulations was estimated utilizing Fuchsin vital stain. Furthermore, the in vivo pharmacokinetics were assessed in rats. The optimum PRZ-PMMs disclosed conciliation between thermodynamic and kinetic stability, high entrapment efficiency (86.29%), spherical nanosized morphology (15.18 nm), and controlled-release characteristics over 24 h (78.22%). ¹H NMR studies verified PRZ assimilation within the micellar core. Additionally, the in vivo results highlighted a significant boosted efficacy of PRZ-PMMs manifested by fecal eggs output and worm burden reduction, which was clearly evident at the lesser PRZ dose, besides a reversed effect for the intestinal histological disruptions. At 50 µg/mL, PRZ-PMMs increased the percent of non-viable eggs to 100% versus 47% for crude PRZ, whilst shell destruction and loss of embryo were only clear with the applied nano-cargo. Moreover, superior bioavailability by 3.43-fold with elongated residence time was measured for PRZ-PMMs compared to PRZ suspension. Practically, our results unravel the potential of PRZ-PMMs as an oral promising tolerable lower dose nanoplatform for more competent PRZ mass chemotherapy.

A Review of Polymeric Micelles and Their Applications

Self-assembly of amphiphilic polymers with hydrophilic and hydrophobic units results in micelles (polymeric nanoparticles), where polymer concentrations are above critical micelle concentrations (CMCs). Recently, micelles with metal nanoparticles (MNPs) have been utilized in many bio-applications because of their excellent biocompatibility, pharmacokinetics, adhesion to biosurfaces, targetability, and longevity. The size of the micelles is in the range of 10 to 100 nm, and different shapes of micelles have been developed for applications. Micelles have been focused recently on bio-applications because of their unique properties, size, shape, and biocompatibility, which enhance drug loading and target release in a controlled manner. This review focused on how CMC has been calculated using various techniques. Further, micelle importance is explained briefly, different types and shapes of micelles are discussed, and further extensions for the application of micelles are addressed. In the summary and outlook, points that need focus in future research on micelles are discussed. This will help researchers in the development of micelles for different applications.

Nanocarriers for Drug Delivery: An Overview with Emphasis on Vitamin D and K Transportation

Mounting evidence shows that supplementation with vitamin D and K or their analogs induces beneficial effects in various diseases, e.g., osteoarticular, cardiovascular, or carcinogenesis. The use of drugs delivery systems via organic and inorganic nanocarriers increases the bioavailability of vitamins and analogs, enhancing their cellular delivery and effects. The nanotechnology-based dietary supplements and drugs produced by the food and pharmaceutical industries overcome the issues associated with vitamin administration, such as stability, absorption or low bioavailability. Consequently, there is a continuous interest in optimizing the carriers' systems in order to make them more efficient and specific for the targeted tissue. In this pioneer review, we try to circumscribe the most relevant aspects related to nanocarriers for drug delivery, compare different types of nanoparticles for vitamin D and K transportation, and critically address their benefits and disadvantages.

Current trends and future perspectives of nanomedicine for the management of colon cancer

Colon cancer (CC) kills countless people every year throughout the globe. It persists as one of the highly lethal diseases to be treated because the overall survival rate for CC is meagre. Early diagnosis and efficient treatments are two of the biggest hurdles in the fight against cancer. In the present work, we will review thriving strategies for CC targeted drug delivery and critically explain the most recent progressions on emerging novel nanotechnology-based drug delivery systems. Nanotechnology-based animal and human clinical trial studies targeting CC are discussed. Advancements in nanotechnology-based drug delivery systems intended to enhance cellular uptake, improved pharmacokinetics and effectiveness of anticancer drugs have facilitated the powerful targeting of specific agents for CC therapy. This review provides insight into current progress and future opportunities for nanomedicines as potential curative targets for CC treatment. This information could be used as a platform for the future expansion of multi-functional nano constructs for CC's advanced detection and functional drug delivery.

High-Loading Self-Assembling Peptide Nanoparticles as a Lipid-Free Carrier for Hydrophobic General Anesthetics

Purpose

Typical hydrophobic amino acids (HAAs) are important motifs for self-assembling peptides (SAPs), but they lead to low water-solubility or compact packing of peptides, limiting their capacity for encapsulating hydrophobic drugs. As an alternative, we designed a peptide GQY based on atypical HAAs, which could encapsulate hydrophobic drugs more efficiently. Although hydrophobic general anesthetics (GAs) have been formulated as lipid emulsions, their lipid-free formulations have been pursued because of some side effects inherent to lipids. Using GAs as targets, potential application of GQY as a carrier for hydrophobic drugs was evaluated.

Methods

Thioflavin-T (ThT) binding test, dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to examine the self-assembling ability of GQY. Pyrene and 8-Anilino-1-naphthalenesulfonic acid (ANS) were used to confirm formation of hydrophobic domain in GQY nanoparticles. Using pyrene as a model, GQY’s capacity to encapsulate hydrophobic drugs was evaluated. GAs including propofol, etomidate and ET26 were encapsulated by GQY. Loss of righting reflex (LORR) test was conducted to assess the anesthetic efficacy of these lipid-free formulations. Paw-licking test was used to evaluate pain-on-injection of propofol-GQY (PROP-GQY) formulation. Hemolytic and cytotoxicity assay were used to evaluate biocompatibility of GQY.

Results

Stable nanoparticles containing plenty of hydrophobic cavities could be formed by GQY, which could encapsulate hydrophobic drugs at very high concentration and form stable suspensions. Propofol, etomidate and ET26 formulated by GQY showed anesthetic efficacy comparable to their currently available formulations. Unlike clinic lipid emulsion, PROP-GQY formulation did not cause pain-on-injection in rats. Neither obvious cytotoxicity nor hemolytic activity of GQY was observed.

Conclusion

GQY could encapsulate GAs to obtain stable and effective formulations. As a lipid-free carrier, GQY exhibited considerable biocompatibility and other side benefits such as reducing pain-on-injection. More SAPs based on atypical HAAs could be designed as promising carriers for hydrophobic drugs.

Harnessing amphiphilic polymeric micelles for diagnostic and therapeutic applications: Breakthroughs and bottlenecks

Amphiphilic block copolymers are widely utilized in the design of formulations owing to their unique physicochemical properties, flexible structures and functional chemistry. Amphiphilic polymeric micelles (APMs) formed from such copolymers have gained attention of the drug delivery scientists in past few decades for enhancing the bioavailability of lipophilic drugs, molecular targeting, sustained release, stimuli-responsive properties, enhanced therapeutic efficacy and reducing drug associated toxicity. Their properties including ease of surface modification, high surface area, small size, and enhanced permeation as well as retention (EPR) effect are mainly responsible for their utilization in the diagnosis and therapy of various diseases. However, some of the challenges associated with their use are premature drug release, low drug loading capacity, scale-up issues and their poor stability that need to be addressed for their wider clinical utility and commercialization. This review describes comprehensively their physicochemical properties, various methods of preparation, limitations followed by approaches employed for the development of optimized APMs, the impact of each preparation technique on the physicochemical properties of the resulting APMs as well as various biomedical applications of APMs. Based on the current scenario of their use in treatment and diagnosis of diseases, the directions in which future studies need to be carried out to explore their full potential are also discussed.

In vitro anticancer evaluation of micelles containing N-(4-(2-((4-methoxybenzyl)amino)ethyl)phenyl)heptanamide, an analogue of fingolimod

Fingolimod has been evaluated for use as an anticancer agent. However, many steps are required to synthesize fingolimod because of its intricate structure. A fingolimod analogue, N-(4-(2-((4-methoxybenzyl)amino)ethyl)phenyl)heptanamide (MPH), also has anti-cancer effects and is easier to synthesize but is poorly soluble in water. To compensate for its poor water solubility, MPH-loaded polymeric micelles were prepared by thin film hydration method using various polymers and the physicochemical properties of the MPH-loaded micelles such as particle size, drug-loading (DL, %), and encapsulation efficiency (EE, %) were evaluated. A storage stability test was conducted to select the final formulation and the release profile of the MPH-loaded micelles was confirmed by in vitro release assay. MPH-loaded mPEG-b-PLA micelles were selected for further testing based on their stability and physicochemical properties; they were stable for stable for 14 days at 4 °C and 25 °C and for 7 days at 37 °C. They showed anti-cancer efficacy against both A549 and U87 cancer cells. Encapsulation of MPH in polymeric micelles did not decrease the in vitro cytotoxicity of MPH. The findings of this study lay the groundwork for future formulations that enable the effective and stable delivery of poorly water-soluble agents.

Atomistic Molecular Dynamics Simulations of Propofol and Fentanyl in Phosphatidylcholine Lipid Bilayers

Atomistic molecular dynamics (MD) and steered MD simulations in combination with umbrella sampling methodology were utilized to study the general anesthetic propofol and the opioid analgesic fentanyl and their interaction with lipid bilayers, which is not yet fully understood. These molecules were inserted into two different fully hydrated phospholipid bilayers, namely, dioleoylphosphatidylcholine (DOPC) and dipalmitoylphosphatidylcholine (DPPC), to investigate the effects that these drugs have on the bilayer. We determined the role of the lipid chain length and saturation on the behavior of the two drugs. Pure, fully hydrated DOPC and DPPC bilayers were also simulated, and the results were in excellent agreement with the experimental values. Various structural and mechanical properties of each system, such as the area per lipid, area compressibility modulus, order parameter, lateral lipid diffusion, hydrogen bonds, and radial distribution functions, have been calculated to assess how the drug molecules affect the different bilayers. From the calculated results, we show that fentanyl and propofol generally follow similar trends in each bilayer but adopt different favorable positions close to the headgroup/chain interface at the carbonyl groups. Propofol was shown to selectively form hydrogen bonds at the carbonyl carbon in each bilayer, whereas fentanyl interacts with water molecules at the headgroup interface. From the calculated free-energy profiles, we determined that both molecules show a preference for the low-density, low-order acyl chain region of the bilayers and both significantly preferred the DOPC bilayer with propofol and fentanyl having energy minima at -6.66 and -43.07 kcal mol^-1, respectively. This study suggests that different chain lengths and levels of saturation directly affect the properties of these two important molecules, which are seen to work together to control anesthesia in surgical applications.

A Mixed Micellar Formulation for the Transdermal Delivery of an Indirubin Analog

Indirubin is an active component of Dang Gui Long Hui Wan, which has been used in traditional Chinese medicine to treat inflammatory diseases as well as for the prevention and treatment of human cancer, such as chronic myeloid leukemia. The therapeutic effects of indirubin analogs have been underestimated due to its poor water solubility and low bioavailability. To improve the solubility and bioavailability of indirubin analogs, we prepared a mixed micellar formulation with Kolliphor® EL and Tween 80 as surfactants, and PEG 400 as a co-surfactant, followed by complexation with (2-hydroxyproply)-β-cyclodextrin at appropriate ratios. Overall, improving the solubility and skin penetration of indirubin analogs can increase clinical efficacy and provide maximum flux through the skin.

A novel drug delivery system of mixed micelles based on poly(ethylene glycol)-poly(lactide) and poly(ethylene glycol)-poly(ɛ-caprolactone) for gambogenic acid

In this study, a novel mixed polymeric micelles formed from biocompatible polymers, poly(ethylene glycol)-poly(lactide) (mPEG-PLA) and poly(ethylene glycol)-poly(ɛ-caprolactone) (mPEG-PCL), used as a novel nanocarrier to encapsulate gambogenic acid (GNA). GNA-loaded mixed polymeric micelles (GNA-MMs) was prepared by cosolvent evaporation method. The mean average size of GNA-MMs was (83.23 ± 1.06) nm (n = 3) and entrapment efficiency (EE%) of GNA-MMs was (90.18 ± 2.59) % (n = 3) as well as (12.36 ± 0.64) % (n = 3) for drug loading (DL%). Transmission electron microscopy revealed that the GNA-MMs were spherical with "core-shell" structures. Compared with free GNA solution, in vitro release of GNA from GNA-MMs showed a two-phase sustained release profile: an initial relatively fast phase and followed by a slower release phase. Pharmacokinetic results also indicated that the GNA-MMs have longer systemic circulation time and slower plasma elimination rate than free GNA solution. Moreover, the in vitro cytotoxicity assay showed that the IC₅₀ values on HepG2 cells for GNA-MMs and free GNA were (5.67 ± 0.02) μM and (9.02 ± 0.03) μM, respectively. In addition, GNA-MMs significantly increased the HepG2 cellular apoptosis in a concentration-dependent manner. In conclusion, the results showed that mPEG-PLA/mPEG-PCL mixed micelles may serve as an ideal drug delivery system for GNA to prolong drug circulation time in body, enhance bioavailability and retained its potent antitumor effect.

Harmine-loaded galactosylated pluronic F68-gelucire 44/14 mixed micelles for liver targeting

Harmine (HM), a phytoconstituent has wide range of pharmacological activities including antimicrobial, antifungal, antioxidative, and anticancer. HM has shown promising anticancer activity against liver cancer cells. However, poor aqueous solubility, multidrug pump P-gp efflux, extensive in vivo metabolism, and rapid elimination due to glucuronidation/sulfation limit clinical utility of HM. In order to overcome the drawbacks of HM, the current work reports preparation of HM-loaded galactosylated pluronic F-68 (PF68)-Gelucire^® 44/14 (GL44) mixed micelles (HM-MM). 3² factorial design was used to investigate the effect of formulation variables on formation HM-loaded mixed micelles. Solvent evaporation method was used for preparation of HM-MM. The optimized HM-MM was evaluated for size, percent drug entrapped (EE), in vitro HM release, oral bioavailability, and biodistribution in rats. HM-MM with an average size 277.5 ± 3.24 nm had an EE of 86.5 ± 1.51% w/w. HM-MM released HM in a controlled manner. Additionally, HM-MM showed significant enhancement in oral bioavailability (around six-folds) of HM when compared to HM alone. Further, HM-MM showed around sevenfold higher amount of HM in the liver when compared to HM alone revealing efficient drug targeting capability. Such significant improvement in oral bioavailability of HM when formulated into mixed micelles could be attributed to solubilization of hydrophobic HM into micellar core along with P-gp inhibition effect of both galactosylated PF68 and GL44. Thus, the present work highlights galactosylated PF68 and GL44 mixed micelles as an efficient carrier system having drug targeting capability and potential to enhance bioavailability of BCS class II drugs.

Solutol HS15 based binary mixed micelles with penetration enhancers for augmented corneal delivery of sertaconazole nitrate: optimization, in vitro, ex vivo and in vivo characterization

Keratomycosis is a serious corneal disease that can cause a permanent visual disability if not treated effectively. Sertaconazole nitrate (STZ), a novel broad spectrum antifungal drug, was suggested as a promising treatment. However, its utility in the ocular route is restricted by its poor solubility, along with other problems facing the ocular delivery like short residence time, and the existing corneal barrier. Therefore, the objective of this study was to formulate STZ loaded binary mixed micelles (STZ-MMs) enriched with different penetration enhancers using thin-film hydration method, based on a 3¹.2² mixed factorial design. Different formulation variables were examined, namely, type of auxiliary surfactant, type of penetration enhancer, and total surfactants: drug ratio, and their effects on the solubility of STZ in MMs (S_M), particle size (PS), polydispersity index (PDI), and zeta potential (ZP) were evaluated. STZ-MMs enhanced STZ aqueous solubility up to 338.82-fold compared to free STZ. Two optimized formulations (MM-8 and MM-11) based on the desirability factor (0.891 and 0.866) were selected by Design expert^® software for further investigations. The optimized formulations were imaged by TEM which revealed nanosized spherical micelles. Moreover, they were examined for corneal mucoadhesion, stability upon dilution, storage effect, and ex vivo corneal permeation studies. Finally, both in vivo corneal uptake and in vivo corneal tolerance were investigated. MM-8 showed superiority in the ex vivo and in vivo permeation studies when compared to the STZ-suspension. The obtained results suggest that the aforementioned STZ loaded mixed micellar system could be an effective candidate for Keratomycosis-targeted therapy.

Galangin loaded galactosylated pluronic F68 polymeric micelles for liver targeting

Galangin possess wide range of pharmacological activities including antiarthritic, hepatoprotective, anti-inflammatory, antibacterial, and anticancer especially in hepatocellular carcinoma. However, its biological use has been limited owing to its poor aqueous solubility, P-gp efflux and rapid in vivo metabolism by cytochrome enzymes. In order to address the drawbacks of galangin, the current work was designed with an objective to prepare liver targeted galangin loaded galactosylated pluronic F68 polymeric (GF68-Gal) micelles. Galactosylated pluronic F68 copolymer was successfully synthesized usi reduction amination method and used for micelle preparation. The prepared micelles were evaluated for micelle size, entrapment efficiency, zeta potential, in vitro galangin release and in vivo biodistribution. The average size of GF68-Gal micelles was found to be around 242±4.6 nm with an entrapment efficiency of about 77.5± 0.34% w/w. In vitro dissolution profile of GF68-Gal micelles revealed controlled release of galangin. Further, biodistribution studies of GF68-Gal micelles showed significant improvement in the amount of galangin in liver at 15 min (around 2.6 folds) and after 30 min (around 7.18 folds) as compared to galangin solution. Such significant increase in galangin amount in the liver for GF68-Gal micelles could be attributed to their efficient targeting to the liver by galactose moieties having affinity towards ASGPR receptor, P-gp and cytochrome enzyme inhibition activity of pluronic F68 reducing the rate of metabolism and in turn elimination. Thus, galactosylated pluronic F68 copolymer can act as a promising carrier system for improving liver targeting of hydrophobic drugs susceptible to P-gp efflux and cytochrome enzyme associated metabolism.

Antineoplastic activity of mitomycin C formulated in nanoemulsions-based essential oils on HeLa cervical cancer cells

Combining the essential oils (ESSOs) with the chemotherapeutic agent, mitomycin C (MMC), in nanoparticle can be beneficial in cancer therapy. The aim of the current study was to in vitro evaluate the antineoplastic effect of MMC, formulated in two different nanoemulsions (NE) based on two ESSOs, chamomile (Ch) and garlic (Gar), on HeLa cervical cancer cells. The z-average diameter of Ch-NE has slightly increased from 83.39 ± 12.85 nm to 91.18 ± 5.79 nm when mixed with MMC (Ch-MMC) whereas the z-average diameter of Gar-NE has markedly increased from 50.6 ± 1.96 nm to 75.64 ± 7.13 nm when loaded with MMC (Gar-MMC). The zeta potentials of both of Ch-NE and Ch-MMC, which were -1.91 ± 4.38 mV and -5.44 ± 5.26 mV, respectively, have differed from Gar-NE and Gar-MMC, which were 11.4 ± 2.29 mV and 11.5 ± 2.28 mV, respectively. Compared to MMC solution, the cell viabilities of HeLa cells, measured by the MTT assay, were reduced 42 and 20 times when subjected into Ch-MMC and Gar-MMC, respectively. The light microscopy images revealed that the cell membrane of the HeLa cells treated with Gar-NE or Gar-MMC were more altered relative to the cells treated with Ch-NE or Ch-MMC. In contrast, the nuclei of the HeLa cells, stained with DAPI and treated with Ch-NE or Ch-MMC, were more fragmented than the cells treated with Gar-NE or Gar-MMC, indicating that both of Ch-NE and Ch-MMC have passed the cell membrane and affected the nucleus directly whereas Gar-NE and Gar-MMC have got attached to the cell membrane causing damage to the cell. In conclusion, combining MMC with NE-based ESSOs has increased the cytotoxic effect of the MMC on the HeLa cells with different mechanism of actions.

Current progress and challenges of nanoparticle-based therapeutics in pain management

Pain is a widespread and growing health problem worldwide that exerts a considerable social and economic impact on both patients and healthcare systems and, therefore, on society in general. Although current treatment modalities include a wide variety of pharmacological and non-pharmacological approaches, due to the complexity of pain and individual differences in clinical response these options are not always effective in mitigating and relieving pain. In addition, some pain drugs such as non-steroidal anti-inflammatory drugs (NSAIDs), local anesthetics and opioids show several unfavorable side effects. Therefore, current research advances in this medical field are based on the development of potential treatments to address many of the unmet needs and to overcome the existing limitations in pain management. Nanoparticle drug delivery systems present an exciting opportunity as alternative platforms to improve efficacy and safety of medications currently in use. Herein, we review a broad range of nanoparticle formulations (organic nanostructures and inorganic nanoparticles), which have been developed to encapsulate an array of painkillers, paying special attention to the key advantages that these systems offer, (compared to the use of the free drug), as well as to the more relevant results of preclinical studies in animal models. Additionally, we will briefly discuss the impact of some of these nanoformulations in clinical trials.

Mixed micelles of lipoic acid-chitosan-poly(ethylene glycol) and distearoylphosphatidylethanolamine-poly(ethylene glycol) for tumor delivery

Many chemotherapeutics suffer from poor aqueous solubility and tissue selectivity. Distearoylphosphatidylethanolamine-poly(ethylene glycol) (DSPE-PEG) micelles are a promising formulation strategy for the delivery of hydrophobic anticancer drugs. However, storage and in vivo instability restrict their use. The aim of this study was to prepare mixed micelles, containing a novel polymer, lipoic acid-chitosan-poly(ethylene glycol) (LACPEG), and DSPE-PEG, to overcome these limitations and potentially increase cancer cell internalisation. Drug-loaded micelles were prepared with a model tyrosine kinase inhibitor and characterized for size, surface charge, stability, morphology, drug entrapment efficiency, cell viability (A549 and PC-9 cell lines), in vivo biodistribution, ex vivo tumor accumulation and cellular internalisation. Micelles of size 30-130nm with entrapment efficiencies of 46-81% were prepared. LACPEG/DSPE-PEG mixed micelles showed greater interaction with the drug (condensing to half their size following entrapment), greater stability, and a safer profile in vitro compared to DSPE-PEG micelles. LACPEG/DSPE-PEG and DSPE-PEG micelles had similar entrapment efficiencies and in vivo tumor accumulation levels, but LACPEG/DSPE-PEG micelles showed higher tumor cell internalisation. Collectively, these findings suggest that LACPEG/DSPE-PEG mixed micelles provide a promising platform for tumor delivery of hydrophobic drugs.

Encapsulation of sesamol in phosphatidyl choline micelles: Enhanced bioavailability and anti-inflammatory activity

Sesamol, the phenolic degradation product of sesamolin, although recognised for its anti-inflammatory effects, has low bioavailability. In this manuscript, we attempted to improve its bioavailability by encapsulation in mixed phosphatidylcholine micelles. Sesamol could be solubilised and entrapped in phosphatidylcholine mixed micelles (PCS) with 96.8% efficiency (particle size 3.0±0.06nm). Fluorescence spectra of PCS revealed lower relative fluorescence intensity (RFI 112) compared to 'free' sesamol (FS) (RFI 271). The bioaccessibility, transport across a monolayer of cells and cellular uptake of PCS was 8.58%, 1.5-fold and 1.2-fold better, respectively, compared to FS. The anti-inflammatory effects of FS and PCS were compared using LPS treated RAW 264.7 cell line and lipoxygenase inhibition. PCS effected downregulation of iNOS protein expression (27%), NO production (20%), ROS (32%) and lipoxygenase inhibition (IC₅₀=31.24μM) compared to FS.

Polymeric mixed micelles as nanomedicines: Achievements and perspectives

During the past few decades, polymeric micelles have raised special attention as novel nano-sized drug delivery systems for optimizing the treatment and diagnosis of numerous diseases. These nanocarriers exhibit several in vitro and in vivo advantages as well as increased stability and solubility to hydrophobic drugs. An interesting approach for optimizing these properties and overcoming some of their disadvantages is the combination of two or more polymers in order to assemble polymeric mixed micelles. This review article gives an overview on the current state of the art of several mixed micellar formulations as nanocarriers for drugs and imaging probes, evaluating their ongoing status (preclinical or clinical stage), with special emphasis on type of copolymers, physicochemical properties, in vivo progress achieved so far and toxicity profiles. Besides, the present article presents relevant research outcomes about polymeric mixed micelles as better drug delivery systems, when compared to polymeric pristine micelles. The reported data clearly illustrates the promise of these nanovehicles reaching clinical stages in the near future.

Mediating physicochemical properties and paclitaxel release of pH-responsive H-type multiblock copolymer self-assembly nanomicelles through epoxidation

We focused on modulation of the physicochemical and biomedical properties of copolymer nanomicellesviaepoxidation, which provided significant improvements.

Novel propofol derivatives and implications for anesthesia practice

Propofol (2,6-diisopropylphenol) is the most commonly used intravenous agent for induction of anesthesia. It is also used for maintenance of anesthesia and sedation in both Intensive Care Units and outpatient procedural settings. Its success in the clinical setting has been a result of its rapid onset, short duration of action, and minimal side effects despite disadvantages associated with its oil emulsion formulation. Early attempts to alter the standard emulsion or to develop new formulations with cyclodextrins and micelles to resolve issues with pain upon injection, the need for antimicrobial agents, and possible hyperlipidemia have mostly failed. With these challenges in the foreground, attention has now shifted to the use of more prodrugs and exogenous alternatives, the success of which is yet to be determined. These new agents must offer significant clinical advantages over the well-entrenched, generic propofol oil emulsion to justify higher costs and to be well received in the increasingly cost-conscious healthcare marketplace.

Building the design, translation and development principles of polymeric nanomedicines using the case of clinically advanced poly(lactide(glycolide))-poly(ethylene glycol) nanotechnology as a model: An industrial viewpoint

The design of the first polymeric nanoparticles could be traced back to the 1970s, and has thereafter received considerable attention, as evidenced by the significant increase of the number of articles and patents in this area. This review article is an attempt to take advantage of the existing literature on the clinically tested and commercialized biodegradable PLA(G)A-PEG nanotechnology as a model to propose quality building and outline translation and development principles for polymeric nano-medicines. We built such an approach from various building blocks including material design, nano-assembly - i.e. physicochemistry of drug/nano-object association in the pharmaceutical process, and release in relevant biological environment - characterization and identification of the quality attributes related to the biopharmaceutical properties. More specifically, as envisaged in a translational approach, the reported data on PLA(G)A-PEG nanotechnology have been structured into packages to evidence the links between the structure, physicochemical properties, and the in vitro and in vivo performances of the nanoparticles. The integration of these bodies of knowledge to build the CMC (Chemistry Manufacturing and Controls) quality management strategy and finally support the translation to proof of concept in human, and anticipation of the industrialization takes into account the specific requirements and biopharmaceutical features attached to the administration route. From this approach, some gaps are identified for the industrial development of such nanotechnology-based products, and the expected improvements are discussed. The viewpoint provided in this article is expected to shed light on design, translation and pharmaceutical development to realize their full potential for future clinical applications.

Impact of hydrogenation on physicochemical and biomedical properties of pH-sensitive PMAA-b-HTPB-b-PMAA triblock copolymer drug carriers

pH-Sensitive poly(methacrylic acid)-block-hydroxyl-terminated polybutadiene-block-poly(methacrylic acid) (PMAA-b-HTPB-b-PMAA) was synthesized and then hydrogenated in this work. The chain structure, phase behavior and thermal properties were characterized by(1)H NMR, FTIR, XRD, DSC, TGA, etc., and the physicochemical and biomedical properties were investigated via fluorescence spectroscopy, TEM, DLS, loading and release of drug and MTT, and so on. The experimental results indicated that the hydrogenation led to the change in the chain aggregate structure of hydrophobic HTPB blocks and the formation of more stable spherical core-shell micelle aggregates, and the critical micelle concentration decreased from 41.8 mg L(-1)before hydrogenation to 4.4 mg L(-1)after hydrogenation. The hydrogenated block copolymer micelle aggregates exhibited pH-triggered response, and could entrap twice as much hydrophobic drug as the unhydrided counterparts and the encapsulation efficiency was significantly improved, which makes them fine to meet the requirements for drug carriers. Therefore, the hydrogenated PMAA-b-HTPB-b-PMAA copolymer micelles as drug target release carriers can be well used in the field of prevention and treatment of cancers.

A novel cabazitaxel-loaded polymeric micelle system with superior in vitro stability and long blood circulation time

Cabazitaxel (CTX) is a second-generation semisynthetic taxane that demonstrates antitumor activity superior to docetaxel. However, the low aqueous solubility of CTX has hampered its use as a therapeutic agent. In this work, CTX-loaded N-t-butoxycarbonyl-L-phenylalanine end-capped monomethyl poly (ethylene glycol)-block-poly (D,L-lactide) (mPEG-PLA-Phe(Boc)/CTX) micelles were prepared to improve the solubility of CTX while retaining its superior stability before accessing the tumor site. The mPEG-PLA-Phe(Boc)/CTX micelles showed excellent stability in vitro compared with mPEG-PLA/CTX micelles. When stored at 25 °C, the mPEG-PLA/CTX micelles tended to aggregate within 1 h, whereas the mPEG-PLA-Phe(Boc)/CTX micelles were uniformly transparent even after three weeks. Dilution of mPEG-PLA/CTX micelles widened their size distribution and decreased the encapsulation efficiency, while significant change was not found in mPEG-PLA-Phe(Boc)/CTX micelles, even when diluted 1000-fold. Pharmacokinetic results in Sprague-Dawley rats indicated that, compared with Jevtana(®), intravenous administration of mPEG-PLA-Phe(Boc)/CTX micelles stably retained the CTX in plasma with 26.03-fold larger of the area under the time-concentration curve, 2.13-fold longer of the half-life, and 9.99-fold higher of the maximum concentration. In conclusion, mPEG-PLA-Phe(Boc) micelle may be a potential nanocarrier not only to improve the solubility of CTX but also to prolong the blood circulation time, which results in improved biological activity.

d-α-Tocopheryl polyethylene glycol 1000 succinate conjugated folic acid nanomicelles: towards enhanced bioavailability, stability, safety, prolonged drug release and synergized anticancer effect of plumbagin

Plumbagin (PLB) loadedd-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) with folic acid (FOL) conjugated nanomicelles achieved controlled and targeted delivery with synergized anticancer potency and reduced PLB toxicity.

Enhanced oral bioavailability and anticancer activity of novel curcumin loaded mixed micelles in human lung cancer cells

BACKGROUND

Curcumin has a wide range of pharmacological activities including antioxidant, anti-inflammatory, antidiabetic, antibacterial, wound healing, antiatherosclerotic, hepatoprotective and anti-carcinogenic. However, its clinical applications are limited owing to its poor aqueous solubility, multidrug pump P-gp efflux, extensive in vivo metabolism and rapid elimination due to glucuronidation/sulfation.

PURPOSE

The objective of the current work was to prepare novel curcumin loaded mixed micelles (CUR-MM) of Pluronic F-127 (PF127) and Gelucire® 44/14 (GL44) in order to enhance its oral bioavailability and cytotoxicity in human lung cancer cell line A549.

STUDY DESIGN

3(2) Factorial design was used to assess the effect of formulation variables for optimization of mixed micelle batch.

METHODS

CUR-MM was prepared by a solvent evaporation method. The optimized CUR-MM was evaluated for size, entrapment efficiency (EE), in vitro curcumin release, cytotoxicity and oral bioavailability in rats.

RESULTS

The average size of CUR-MM was found to be around 188 ± 3 nm with an EE of about 76.45 ± 1.18% w/w. In vitro dissolution profile of CUR-MM revealed controlled release of curcumin. Additionally, CUR-MM showed significant improvement in cytotoxic activity (3-folds) and oral bioavailability (around 55-folds) of curcumin as compared to curcumin alone. Such significant improvement in cytotoxic activity and oral bioavailability of curcumin when formulated into mixed micelles could be attributed to solubilization of hydrophobic curcumin into micelle core along with P-gp inhibition effect of both, PF127 and GL44.

CONCLUSION

Thus the present work propose the formulation of mixed micelles of PF127 and GL44 which can act as promising carrier systems for hydrophobic drugs such as curcumin with significant improvement in their oral bioavailability.

Sirolimus-loaded polymeric micelles with honokiol for oral delivery

Objectives

The aims of the present study were to design polymeric micelles loading sirolimus with honokiol to increase drug solubility and to gain an insight into the effect of honokiol on oral transport of P-glycoprotein substrate (P-gp).

Methods

Particle size distribution, encapsulation efficiency, drug-loading content and in-vitro release of sirolimus-loaded micelles with honokiol were determined. Transport of sirolimus-loaded micelles across Caco-2 cell monolayers and jejunum segment of rats were investigated. In-vitro cytotoxicity experiments and the cellular uptake study were carried out via sulforhodamine B assay and flow cytometry, respectively.

Key findings

A coadministration of honokiol with sirolimus in micelles did not significantly modify the particle size, polydispersity index and release of drugs demonstrating successful loading within the micelles. The apparent transport coefficients (Papp) and effective permeability (Peff) of sirolimus were increased with more amount of honokiol loaded in micelles. Cellular uptake study demonstrated that rhodamine123 uptake rate was enhanced by honokiol-loaded micelles, indicating substantial P-gp inhibition action by honokiol and mPEG-PLA-based micelles.

Conclusion

Oral transport of sirolimus was significantly improved by coadministration with honokiol, an inhibitor of the P-gp, in polymeric micelles formulation.

Synthesis and evaluation of hydroponically alginate nanoparticles as novel carrier for intravenous delivery of propofol

Commercial lipid emulsion of propofol (CLE) has several drawbacks including pain on injection and emulsion instability. In this paper, a novel nanocarrier system is introduced to improve stability and solubility of the poorly soluble anesthetic drug, propofol, for intravenous administration. In this paper, alginate is modified using a facile method in which the carboxylic group of alginate is grafted to octanol. The octanol-grafted alginate (Alg-C8) is then employed to prepare nanoparticles which are subsequently used for encapsulation of propofol. The nanoparticles are analyzed for their pH, osmolarity, particle size, stability, morphology and sleep recovery and the results are compared with CLE as control. It is revealed that nanoparticles have the average particle size of 180 nm ± 1.2 and spherical morphology which is less than CLE while their pH, osmolarity and profile of release of formulated nanoparticles are similar to those of CLE. In addition, the results show good chemical and physical storage stability for the nanoparticles at room temperature for at least 6 months compared to CLE as control. The animal sleep recovery test on rats shows no significant difference in time of unconsciousness and recovery of the righting reflex between nanoparticles and CLE. It is concluded that encapsulated nanoparticles introduced here could be a promising clinical intravenous system for delivery of poorly soluble anesthetic propofol. In addition, this study provides an efficient and facile method for preparing a carrier system for water insoluble drugs.

Preparation, optimization, characterization and cytotoxicity in vitro of Baicalin-loaded mixed micelles

The aim of this study was to develop a Baicalin (BC)-loaded mixed micelle delivery system (BC-ST-P123-MMs) with sodium taurocholate (ST) and pluronic P123 block copolymer (P123) as carrier materials to improve the solubility of BC, a poorly soluble drug. In this study, the mixed micelle system was prepared using the method of thin-film dispersion and then optimized by the homogeneous design-response surface methodology with the entrapment efficiency and drug loading as indexes. The average size and the zeta potential of the BC-ST-P123-MMs were 15.60 nm and -5.26 mV, respectively. Drug loading (DL, 16.94%) and entrapment efficiency (EE, 90.67%) contributed to high solubility (10.20 mg/mL) of BC in water. The optimized BC-ST-P123-MMs appeared spherical with obvious core-shell structure and well dispersed without aggregation and adhesion under TEM. In addition, DSC result indicated that BC had been wrapped in BC-ST-P123-MMs and crystalline state of BC was changed. The release result in vitro showed that BC-ST-P123-MMs presented sustained release behavior compared to control group. The IC50 value of BC-ST-P123-MMs (46.18 μg/mL) was lower than that of BC solution (67.14 μg/mL) on Hep G2 cell lines. Cellular uptake tests illustrated that the ST-P123-MMs system as carrier could significantly enhance the uptake of drugs by tumor cells. The results demonstrated that the BC-loaded mixed micelles could improve solubility of BC and exhibited great potential for delivering drug into cancer cells.

A critical appraisal of microemulsions for drug delivery: part I

Microemulsions (MEs) are thermodynamically stable, optically transparent isotropic solutions of oil and water successfully formulated by using a combination of suitable surfactant and cosurfactant. While the selection of oil is based primarily on the solubility of drug in it, surfactant is generally selected on the basis of its hydrophilic–lipophilic balance value. MEs are characterized by ultra-low interfacial tension between the immiscible phases and offer the advantage of spontaneous formation, thermodynamic stability and ease of manufacture. The solubilization power of MEs for lipophilic, hydrophilic and amphiphilic solutes form a viable approach for enhancing bioavailability of hydrophobic drugs and percutaneous permeation of poorly permeable drugs, mainly due to the large area to volume ratio available for mass transfer.

Development of plumbagin-loaded phospholipid–Tween® 80 mixed micelles: formulation, optimization, effect on breast cancer cells and human blood/serum compatibility testing

Background: Phospholipid and Tween® 80 mixed micelles were investigated as injectable nanocarriers for the natural anticancer compound, plumbagin (PBG), with the aim to improve anticancer efficiency. PBG-loaded mixed micelles were fabricated by self-assembly; composition being optimized using 32 factorial design. Results & discussion: Optimized mixed micelles were spherical and 46 nm in size. Zeta potential, drug loading and encapsulation efficiency were 5.04 mV, 91.21 and 98.38% respectively. Micelles demonstrated sustained release of PBG. Micelles caused a 2.1-fold enhancement in vitro antitumor activity of PBG towards MCF-7 cells. Micelles proved safe for intravenous injection as PBG was stable at high pH; micelle size and encapsulation efficiency were retained upon dilution. Conclusion: Developed mixed micelles proved potential nanocarriers for PBG in cancer chemotherapy.

pH-sensitive micelles for targeted drug delivery prepared using a novel membrane contactor method

A novel membrane contactor method was used to produce size-controlled poly(ethylene glycol)-b-polycaprolactone (PEG-PCL) copolymer micelles composed of diblock copolymers with different average molecular weights, Mn (9200 or 10,400 Da) and hydrophilic fractions, f (0.67 or 0.59). By injecting 570 L m(-2) h(-1) of the organic phase (a 1 mg mL(-1) solution of PEG-PCL in tetrahydrofuran) through a microengineered nickel membrane with a hexagonal pore array and 200 μm pore spacing into deionized water agitated at 700 rpm, the micelle size linearly increased from 92 nm for a 5-μm pore size to 165 nm for a 40-μm pore size. The micelle size was finely tuned by the agitation rate, transmembrane flux and aqueous to organic phase ratio. An encapsulation efficiency of 89% and a drug loading of ~75% (w/w) were achieved when a hydrophobic drug (vitamin E) was entrapped within the micelles, as determined by ultracentrifugation method. The drug-loaded micelles had a mean size of 146 ± 7 nm, a polydispersity index of 0.09 ± 0.01, and a ζ potential of -19.5 ± 0.2 mV. When drug-loaded micelles where stored for 50 h, a pH sensitive drug release was achieved and a maximum amount of vitamin E (23%) was released at the pH of 1.9. When a pH-sensitive hydrazone bond was incorporated between PEG and PCL blocks, no significant change in micelle size was observed at the same micellization conditions.

Preparation of hierarchical mesoporous CaCO3 by a facile binary solvent approach as anticancer drug carrier for etoposide

To develop a nontoxic system for targeting therapy, a new highly ordered hierarchical mesoporous calcium carbonate nanospheres (CCNSs) as small drug carriers has been synthesized by a mild and facile binary solvent approach under the normal temperature and pressure. The hierarchical structure by multistage self-assembled strategy was confirmed by TEM and SEM, and a possible formation process was proposed. Due to the large fraction of voids inside the nanospheres which provides space for physical absorption, the CCNSs can stably encapsulate the anticancer drug etoposide with the drug loading efficiency as high as 39.7 wt.%, and etoposide-loaded CCNS (ECCNS) nanoparticles can dispersed well in the cell culture. Besides, the drug release behavior investigated at three different pH values showed that the release of etoposide from CCNSs was pH-sensitive. MTT assay showed that compared with free etoposide, ECCNSs exhibited a higher cell inhibition ratio against SGC-7901 cells and also decreased the toxicity of etoposide to HEK 293 T cells. The CLSM image showed that ECCNSs exhibited a high efficiency of intracellular delivery, especially in nuclear invasion. The apoptosis test revealed that etoposide entrapped in CCNSs could enhance the delivery efficiencies of drug to achieve an improved inhibition effect on cell growth. These results clearly implied that the CCNSs are a promising drug delivery system for etoposide in cancer therapy.