Oral delivery of posaconazole-loaded phospholipid-based nanoformulation: Preparation and optimization using design of experiments, machine learning, and TOPSIS

Phospholipid-based nanosystems show promising potentials for oral administration of hydrophobic drugs. The study introduced a novel approach to optimize posaconazole-loaded phospholipid-based nanoformulation using the design of experiments, machine learning, and Technique for Order of Preference by Similarity to the Ideal Solution. These approaches were used to investigate the impact of various variables on the encapsulation efficiency (EE), particle size, and polydispersity index (PDI). The optimized formulation, with %EE of ∼ 74 %, demonstrated a particle size and PDI of 107.7 nm and 0.174, respectively. The oral pharmacokinetic profiles of the posaconazole suspension, empty nanoformulation + drug suspension, and drug-loaded nanoformulation were evaluated. The nanoformulation significantly increased maximum plasma concentration and the area under the drug plasma concentration-time curve (∼3.9- and 6.2-fold, respectively) and could be administered without regard to meals. MTT and histopathological examinations were carried out to evaluate the safety of the nanoformulation and results exhibited no significant toxicity. Lymphatic transport was found to be the main mechanism of oral delivery. Caco-2 cell studies demonstrated that the mechanism of delivery was not based on an increase in cellular uptake. Our study represents a promising strategy for the development of phospholipid-based nanoformulations as efficient and safe oral delivery systems.

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

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

Preparation of multivesicular liposomes for the loco-regional delivery of Vancomycin hydrochloride using active loading method: drug release and antimicrobial properties

Over the last few years, among controlled-release delivery systems, multivesicular liposomes (MVLs) have attracted attention due to their unique benefits as a loco-regional drug delivery system. Considering the clinical limitations of the current treatment strategies for osteomyelitis, MVLs can be a suitable carrier for the local delivery of effective antibiotics. This study aimed to prepare vancomycin hydrochloride (VAN HL) loaded MVLs using the active loading method which to the best of our knowledge has not been previously reported. Empty MVLS were prepared by the double emulsion (w/o/w) method and VAN HL was loaded into the prepared liposomes by the ammonium gradient method. After full characterization, the release profile of VAN HL from MVLs was assessed at two different pH values (5.5 and 7.4), and compared with the release profile of the free drug and also passively loaded MVLs. In vitro antimicrobial activities were evaluated using the disc diffusion method. Our results demonstrated that the encapsulation efficiency was higher than 90% in the optimum actively loaded MVL. The free VAN HL was released within 6-8 h, while the passively loaded MVLs and the optimum actively loaded MVL formulation released the drug in 6 days and up to 19 days, respectively. The released drug showed effective antibacterial activity against osteomyelitis-causing pathogens. In conclusion, the prepared formulation offered the advantages of sustained-release properties, appropriate particle size as well as being composed of biocompatible materials, and thus could be a promising candidate for the loco-regional delivery of VAN HL and the management of osteomyelitis.

Berberine-phospholipid nanoaggregate-embedded thiolated chitosan hydrogel for aphthous stomatitis treatment

Aim: This study aimed to develop nanoaggregates of berberine-phospholipid complex incorporated into thiolated chitosan (TCS) hydrogel for the treatment of aphthous stomatitis. Methods: The berberine-phospholipid complex was formulated through the solvent evaporation technique and assembled into nanoaggregates. TCS was synthesized through the attachment of thioglycolic acid to chitosan (CS). Nanoaggregates-TCS was prepared by the incorporation of nanoaggregates into TCS and underwent in vitro and in vivo tests. Results: Nanoaggregates-TCS exhibited prolonged release of berberine. The mucoadhesive strength of nanoaggregates-TCS increased 1.75-fold compared with CS hydrogel. In vivo studies revealed the superior therapeutic efficacy of nanoaggregates-TCS compared with that of other groups. Conclusion: Due to prolonged drug release, appropriate residence time and anti-inflammatory effects, nanoaggregates-TCS is an effective system for the treatment of aphthous stomatitis.

Piperine Liposome-Embedded in Hyaluronan Hydrogel as an Effective Platform for Prevention of Postoperative Peritoneal Adhesion

This study aimed to prepare piperine (PIP) loaded liposomes in hyaluronic acid (HA) hydrogel to provide a hybrid superstructure for postoperative adhesion prevention. Liposomes were prepared using thin-film hydration method. The optimised formulation was characterised by size, SEM, TEM, FTIR, encapsulation efficiency (EE)% (w/w), and release pattern. Liposome-in-hydrogel formulation was investigated by rheology, SEM, and release studies. The efficacy was evaluated in a rat peritoneal abrasion model. EE% (w/w) increased with increasing lipid concentration from 10 to 30; however, a higher percentage of Chol reduced EE% (w/w). The optimised liposome (EE: 68.10 ± 4.18% (w/w), average diameter: 513 ± 14.67 nm, PDI: 0.15 ± 0.04) was used for hydrogel embedding. No sign of adhesion in 5/8 rats and no collagen deposition confirmed the in vivo effectiveness of the optimised formulation. Overall, providing a sustained delivery of PIP, the developed liposome-in-hydrogel formulation can be a promising carrier to prevent postoperative adhesion.

Biocompatible phospholipid-based mixed micelles for posaconazole ocular delivery: Development, characterization, and in - vitro antifungal activity

Current study intended to prepare and evaluate phospholipid-based, mixed micelles (MMs) to improve the ocular delivery of posaconazole (POS), a broad-spectrum antifungal drug. For this, MMs based on egg phosphatidylcholine (EPC), as the main component, in combination with various bile salts (sodium cholate (NaC), sodium deoxycholate (NaDC), sodium taurocholate (NaTC)) or non-ionic surfactants (Pluronic® F-127, Pluronic® F-68, Tween 80, Labrasol® ALF, and d-a-tocopheryl polyethylene glycol 1000 succinate (TPGS)) were prepared. Particle size, polydispersity index, zeta potential and entrapment efficiency were evaluated to optimize the composition and preparation method of the MMs. Finally, morphology, stability, in vitro release pattern, and in vitro antifungal activity of the optimized formulation were investigated. Among the prepared MMs, vesicles composed of EPC: TPGS with a molar ratio of 70:30, prepared by the thin-film hydration method, showed more appropriate features. Among the prepared MMs, vesicles composed of EPC: TPGS with a molar ratio of 70:30 showed more appropriate features, including an entrapment efficiency (EE) greater than 80%, spherical shape morphology, an average particle size of about 58 nm, desirable stability over a month, slow-release without a noticeable initial burst, and a significantly higher in vitro antifungal activity in comparison with the drug suspension. Therefore, this formulation was selected as the optimal MMs and could be considered as a promising carrier for topical ocular delivery of POS.

Cerasome Versus Liposome: A Comparative Pharmacokinetic Analysis Following Intravenous Administration into Rats

Background

Cerasomes, due to their external siloxane network, demonstrate markedly higher physicochemical stability and, therefore, easier handling and storage than liposomes.

Objectives

The main objective of this study was to compare the pharmacokinetics (PK) of cerasome and liposome following intravenous administration. The PK of PEGylated and non-PEGylated cerasomes was also compared to see whether the presence of a hydrophilic siloxane network on the surface of cerasomes can play the role of polyethylene glycol (PEG) in increasing the blood circulation of these vesicles.

Methods

Silver sulfide (Ag2S) quantum dots (Qds)-loaded PEGylated and non-PEGylated cerasomes and PEGylated liposomes were fabricated and thoroughly characterized in terms of particle size, polydispersity index, zeta potential, entrapment efficiency, and in vitro stability. For pharmacokinetic evaluation, the free Qds and the selected formulations were intravenously injected into rats, and blood samples were collected for up to 72 hours. Pharmacokinetic parameters were calculated by the non-compartmental method.

Results

Both cerasomal and liposomal carriers significantly improved the PK of Qds. For example, the elimination half-life (t1/2) and the area under the plasma concentration-time curve from time 0 to time infinity (AUC0-∞) for the free Qds were 4.39 h and 8.01 µg/mL*h and for cerasomal and liposomal formulations were 28.82 versus 26.95 h and 73.25 versus 62.02 µg/mL*h, respectively. However, compared to each other, the plasma concentration-time profiles of PEGylated cerasomes and liposomes displayed similar patterns, and the statistical comparison of their pharmacokinetic parameters did not show any significant difference between the two types of carriers. For PEGylated cerasomes, t1/2 and AUC0-∞ values were respectively 1.6 and 3.3 times greater than the classic cerasome, indicating that despite the presence of a hydrophilic siloxane network, the incorporation of PEG is necessary to reduce the clearance of cerasomes.

Conclusions

The comparable PK of PEGylated cerasomes and liposomes, along with the higher physicochemical stability of cerasomes, can be considered an important advantage for the clinical application of cerasomes. Additionally, the easy surface functionalizing ability of cerasomes confers a dual advantage over liposomes. The study findings also showed that the presence of a hydrophilic siloxane network on the surface of cerasomes alone is not enough to make them circulate long.

Amphotericin B Pharmacokinetics: Inter-strain Differences in Rats Following Intravenous Administration of the Most Commonly Marketed Formulations of the Drug

Background

Amphotericin B (AmB) is the first-line drug to treat invasive fungal infections. However, its delivery to the body and clinical use faces many challenges because of its poor solubility, poor pharmacokinetics, and severe nephrotoxicity.

Objectives

Due to the necessity for designing safer and more effective nanocarriers for AmB and the importance of preclinical pharmacokinetic studies in evaluating these novel drug delivery systems, the present study was framed to explore the influence of rat strain on the pharmacokinetic profile of this drug.

Methods

Twenty-four Wistar and Sprague-Dawley (SD) rats were intravenously injected with 1 mg/kg AmB as Fungizone or AmBisome, which are the two most commonly marketed formulations of the drug. Blood samples were collected before and at regular intervals up to 24 h after administration. Drug concentration was analyzed by a validated HPLC method, and pharmacokinetic parameters were determined by the non-compartmental method.

Results

Irrespective of the type of formulation, the AUC0-t and AUC0-∞ values were significantly higher (P < 0.001), and Cl as an important PK parameter was markedly lower (P < 0.001) in SD rats compared to the Wistar strain. For Fungizone, the mean Cl values in SD and Wistar rats were 206.90 and 462.95 mL/h/kg (P < 0.001), respectively. The apparent volume of distribution (Vss) was also lower in SD rats compared to Wistar; however, for AmBisome, the difference in Vss was not statistically significant. Our further investigation suggested that the higher amount of total protein in the SD strain may justify the higher plasma concentrations and lower Cl and Vss of amphotericin B in this strain compared to the Wistar strain.

Conclusions

Overall, following intravenous administration of AmB, there were significant differences in the pharmacokinetic parameters of the drug between two rat strains for both formulations. The obtained data is important for correctly interpreting experimental data from different research groups.

Particle Size Tailoring of Quercetin Nanosuspensions by Wet Media Milling Technique: A Study on Processing and Formulation Parameters

Background

A large number of new substances have insufficient biopharmaceutical properties for oral administration caused by their slow dissolution rate and poor solubility.

Objective

The purpose of our experiment was to improve the physicochemical properties of a hydrophobic drug, quercetin, by the nanomilling approach.

Methods

Quercetin nanosuspensions were prepared using a wet-milling method followed by lyophilization. Stabilizer type and ratio, drug content, milling time, and bead size were identified as critical variables, and their impacts on quercetin particle size were assessed. The optimized nanocrystal was characterized by its morphology, crystallinity, molecular interactions, saturation solubility, and dissolution properties.

Results

At optimized process conditions of milling at 500 rpm for 18 cycles of grinding with 0.3 - 0.4 mm zirconium oxide beads, minimum particle size, and PDI values were 281.21 nm and 0.22, respectively. Nanocrystals showed rod-like nanostructures, and XRD scans confirmed a decrease in drug crystallinity. The optimized formulation showed increased solubility and dissolution rate, as well as good physical stability.

Conclusions

Particle size reduction by media milling technique was an efficient method for the solubility enhancement of hydrophobic drugs.

Doxorubicin-Loaded Multivesicular Liposomes (DepoFoam) as a Sustained Release Carrier Intended for Locoregional Delivery in Cancer Treatment: Development, Characterization, and Cytotoxicity Evaluation

Background

Despite the advantages of direct intratumoral (IT) injection, the relatively rapid withdrawal of most anti-cancer drugs from the tumor due to their small molecular size limits the effectiveness of this method of administration. To address these limitations, recently, increasing attention has been directed to using slow-release biodegradable delivery systems for IT injection.

Objectives

This study aimed to develop and characterize a doxorubicin-loaded DepoFoam system as an efficient controlled-release carrier to be employed for locoregional drug delivery in cancer treatment.

Methods

Major formulation parameters, including the molar ratio of cholesterol to the main lipid [Chol/egg phosphatidylcholine (EPC)], triolein (TO) content, and lipid-to-drug molar ratio (L/D), were optimized using a two-level factorial design approach. The prepared batches were evaluated for encapsulation efficiency (EE) and percentage of drug release (DR) after 6 and 72 hours as dependent variables. The optimum formulation (named DepoDOX) was further evaluated in terms of particle size, morphology, zeta potential, stability, Fourier-transform infrared spectroscopy, in vitro cytotoxicity, and hemolysis.

Results

The analysis of factorial design indicated that TO content and L/D ratio had a negative effect on EE; between these two, TO content had the greatest effect. The TO content was also the most significant component, with a negative effect on the release rate. The ratio of Chol/EPC showed a dual effect on the DR rate. Using a higher percentage of Chol slowed down the initial release phase of the drug; nevertheless, it accelerated the DR rate in the later slow phase. DepoDOX were spherical and honeycomb-like structures (≈ 9.81 μm) with a desired sustained release profile, as DR lasted 11 days. Its biocompatibility was confirmed by the results of cytotoxicity and hemolysis assays.

Conclusions

The in vitro characterization of optimized DepoFoam formulation demonstrated its suitability for direct locoregional delivery. DepoDOX, as a biocompatible lipid-based formulation, showed appropriate particle size, high capability for encapsulating doxorubicin, superior physical stability, and a markedly prolonged DR rate. Therefore, this formulation could be considered a promising candidate for locoregional drug delivery in cancer treatment.

The Impact of Process and Formulation Parameters on the Fabrication of Efavirenz Nanosuspension to Improve Drug Solubility and Dissolution

Background

Efavirenz nanosuspensions (EZ-NSs) were developed by the wet milling method as the most promising top-down nanosizing technique. Different process and formulation parameters were studied and optimized to produce appropriate EZ-NS in suitable conditions to enhance drug dissolution.

Methods

In the preliminary studies, various polymeric stabilizers, including Pluronic F68, sodium carboxymethylcellulose (CMC), hydroxypropyl methylcellulose (HPMC), and polyvinyl alcohol (PVA), as well as different sizes and weight of milling beads were used to prepare NSs. The effect of sodium lauryl sulfate (SLS) concentration on the NS properties was also evaluated. The influence of other formulation and process parameters, including polymer concentration, milling speed, and milling time, on the particle size and distribution of NSs were investigated using Box-Behnken design. The optimized freeze-dried nanosuspension was characterized by redispersibility, physicochemical properties, and stability.

Results

A combination of PVA and SLS was selected as steric and electrostatic stabilizers. The optimum EZ-NS displayed a uniform size distribution with a mean particle size and zeta potential of 254.4 nm and 21.1 mV, respectively. The solidified nanosuspension was well redispersed to the original nanoparticles. Significantly enhanced aqueous solubility (about 11-fold) and accelerated dissolution rate were observed for the optimized formulation. This could be attributed to the reduced particle size and partial amorphization of EZ during the preparation process, studied by X-ray diffraction. Accelerated studies confirmed the stability of the optimum freeze-dried formulation over the examined period of three months.

Conclusions

Optimization of different variables led to the formation of EZ-NSs with desired properties through wet milling in a very short time compared to the previous study and therefore reduced production costs. This formulation seems to be a suitable approach for solubility and dissolution enhancement of EZ and may have a great potential to improve the drug's oral bioavailability.

Sirolimus-exuding core-shell nanofibers as an implantable carrier for breast cancer therapy: preparation, characterization, in vitro cell studies, and in vivo anti-tumor activity

OBJECTIVE

Breast cancer accounts for significant mortality worldwide. Here, we develop a localized, sustained-release delivery system for breast cancer therapy.

METHODS

Sirolimus (SIR) core-shell nanofibers (NFs) are fabricated by coaxial electrospinning with poly(ε-caprolactone) (PCL) for the core and chitosan and PCL for the shell. The NFs were characterized by SEM, AFM, TEM, XRD, FTIR, water uptake, water contact angle, mechanical properties, drug content, and in vitro release. In vitro and in vivo anticancer effects were investigated.

RESULTS

A sustained release behavior is observed during 480 h that is more extended compared to monoaxial NFs. In vitro cytotoxicity and Annexin V/propidium iodide assays indicate that SIR-loaded coaxial NFs are effective in inhibiting proliferation of 4T1 and MCF-7 cells. Implantation of SIR NFs in 4T1 breast tumor-bearing mice inhibits tumor growth significantly compared to free drug. Histopathological examination shows that suppression of tumor growth by SIR NFs is associated with apoptotic cell death. Furthermore, anti-cancer effects are also confirmed by decreased expression levels of Ki-67, MMP-2, and MMP-9. Histological observation of organs, serological analyses, and the lack of body weight changes indicate in vivo safety of SIR NFs.

CONCLUSIONS

Altogether, we show here that incorporation of SIR into core-shell NFs could act as an effective drug release depot and induce a sustained antitumor response.

Piperine-loaded electrospun nanofibers, an implantable anticancer controlled delivery system for postsurgical breast cancer treatment

Tumorectomy followed by radiotherapy, hormone, and chemotherapy, are the current mainstays for breast cancer treatment. However, these strategies have systemic toxicities and limited treatment outcomes. Hence, there is a crucial need for a novel controlled release delivery system for implantation following tumor resection to effectively prevent recurrence. Here, we fabricated polycaprolactone (PCL)-based electrospun nanofibers containing piperine (PIP), known for chemopreventive and anticancer activities, and also evaluated the impact of collagen (Coll) incorporation into the matrices. In addition to physicochemical characterization such as morphology, hydrophilicity, drug content, release properties, and mechanical behaviors, fabricated nanofibers were investigated in terms of cytotoxicity and involved mechanisms in MCF-7 and 4T1 breast tumor cell lines. In vivo antitumor study was performed in 4T1 tumor-bearing mice. PIP-PCL⁷⁵-Coll²⁵ nanofiber was chosen as the optimum formulation due to sustained PIP release, good mechanical performance, and superior cytotoxicity. Demonstrating no organ toxicity, animal studies confirmed the superiority of locally administered PIP-PCL⁷⁵-Coll²⁵ nanofiber in terms of inhibition of growth tumor, induction of apoptosis, and reduction of cell proliferation compared to PIP suspension, blank nanofiber, and the control. Taken together, we concluded that PIP-loaded nanofibers can be introduced as a promising treatment for implantation upon breast tumorectomy.

Pharmacokinetics, tissue distribution and peritoneal retention of Ag2S quantum dots following intraperitoneal administration to mice

OBJECTIVES

To investigate the pharmacokinetics, biodistribution and peritoneal retention of Ag2S quantum dots (Qds) after intraperitoneal (IP) injection into mice and to compare the results with those reported for the intravenous (IV) injection of these particles.

METHODS

Ag2S Qds was prepared by a simple one-step co-precipitation method and was injected intraperitoneally into mice. Six animals were sacrificed at predetermined time points, and blood, peritoneal content and tissue samples were collected. Ag concentration that represents the concentration of Qds was analysed by atomic absorption spectrophotometry.

KEY FINDINGS

Detectability of Qds in the peritoneal sample up to 2 h indicated that, compared with small drug molecules, the absorption of Ag2S Qds from the peritoneal cavity occurred at a slower rate. The AUC tissue/AUC blood ratio in the liver and intestine after IP injection (0.55 and 0.98, respectively) was considerably lower than those for the bolus injection (217 and 94, respectively), while this ratio in the spleen and lungs was markedly higher than the IV route.

CONCLUSIONS

Overall, the obtained results suggest that IP injection of Ag2S Qds could be more effective for drug delivery to/imaging of the spleen and lungs, whereas the IV injection for the drug delivery to/imaging of the liver and intestine.

Multivesicular liposomal depot system for sustained delivery of risperidone: development, characterization, and toxicity assessment

OBJECTIVE

Considering the limitations of conventional risperidone (RSP) therapies, the present research characterizes the usefulness of multivesicular liposomes (MVLs) as an efficient controlled-release carrier for this widely used antipsychotic drug, to be employed for the treatment of schizophrenia.

METHODS

A 2³ full factorial design based on three independent variables was implemented to plan the experiments: the molar ratios of lipid to the drug, triolein to phospholipid, and cholesterol to phospholipid. The impacts of these parameters on the risperidone encapsulation efficiency and its release pattern within the first 24 and 48 h were investigated as dependent variables. Then, the optimized liposomal system was further in-depth analyzed in terms of size, morphological and structural features, release profile over 15 days, biocompatibility, and stability.

RESULTS

Optimized formulation parameters gave rise to MVLs possessing a spherical morphology with a median diameter of about 8 μm, a relatively narrow size distribution (span value of 1.49), and an encapsulation efficiency of 57.6%. These carriers not only exhibited a sustained-release behavior in vitro, lasting until the end of the 15 days but also underwent a negligible change in their size and RSP incorporation over two months at refrigerator condition. Furthermore, in vitro cytotoxicity and hemolysis assessments revealed that the optimized MVL formulation is biocompatible.

CONCLUSION

This study revealed the potential of MVLs as a promising system for the delivery of RSP and could open a new vista for the successful management of schizophrenia.

An investigation of affecting factors on MOF characteristics for biomedical applications: A systematic review

Metal-organic frameworks (MOFs) are a fascinating class of crystalline porous materials composed of metal ions and organic ligands. Due to their attractive properties, MOFs can potentially offer biomedical field applications, such as drug delivery and imaging. This study aimed to systematically identify the affecting factors on the MOF characteristics and their effects on structural and biological characteristics. An electronic search was performed in four databases containing PubMed, Scopus, Web of Science, and Embase, using the relevant keywords. After analyzing the studies, 20 eligible studies were included in this review. As a result, various factors such as additives and organic ligand can influence the size and structure of MOFs. Additives are materials that can compete with ligand and may affect the nucleation and growth processes and, consequently, particle size. The nature and structure of ligand are influential in determining the size and structure of MOF. Moreover, synthesis parameters like the reaction time and initial reagents ratio are critical factors that should be optimized to regulate the size and structure. Of note is that the nature of the ligand and using a suitable additive can control the porosity of MOF. The more extended ligands aid in forming large pores. The choice of metallic nodes and organic ligand, and the MOF concentration are important factors since they can determine toxicity and biocompatibility of the final structure. The physicochemical properties of MOFs, such as hydrophobicity, affect the toxicity of nanoparticles. An increase in hydrophobicity causes increased toxicity of MOF. The biodegradability of MOF, as another property, depends on the organic ligand and metal ion and environmental conditions like pH. Photocleavable ligands can be served for controlled degradation of MOFs. Generally, by optimizing these affecting factors, MOFs with desirable properties will be obtained for biomedical applications.

An enzyme-mediated controlled release system for curcumin based on cyclodextrin/cyclodextrin degrading enzyme

In this study, an enzyme-triggered system based on β-cyclodextrin (β-CD) has been developed to achieve controlled release of hydrophobic drugs in the presence of maltogenic amylase (MAase). The inclusion complex formation of curcumin (CUR), as a model anticancer compound, with β-CD was characterized by fluorescence and Fourier transform infrared (FTIR) spectroscopy. CUR was loaded into β-CD with an encapsulation efficiency of approximately 30 %. The in vitro profiles of CUR release from β-CD showed that 100 % of the drug was released after one hour incubation in the presence of MAase with cyclodextrin degrading activity. Fluorescence microscopy images indicate a significantly greater cellular uptake of CUR using β-CD-CUR/MAase system compared to β-CD-CUR inclusion complex without MAase. The β-CD-CUR/MAase system exhibited lower IC₅₀ values and greater anti-proliferative effects in comparison with free CUR and β-CD-CUR in MCF-7 and Huh-7 cancer cells. The results from fluorescence microscopy and flow cytometric assay using the acridine orange/ethidium bromide and Annexin V-PE/7-AAD staining suggest that the β-CD-CUR/MAase system exhibited higher cytotoxic and apoptotic effects on cancer cells compared to other formulations. This triggered release of CUR in the presence of MAase is owing to the β-CD degradation by MAase resulting ring opening and chain scission in β-CD. We demonstrate that this enzyme-mediated controlled release system has a potential application for controlled release of poorly water-soluble drugs or hydrophobic compounds such as CUR.

Ameliorative effect of a nano chromium metal-organic framework on experimental diabetic chronic kidney disease

Metal-Organic Frameworks (MOFs) are a new class of crystalline porous structures which can be used as a novel structure in diverse fields of medical science. Several studies have shown that chromium supplementation can be effective in amelioration of biochemical parameters of diabetes and its renal complications. Therefore, a chromium-containing MOF (DIFc) was synthetized by nanochelating technology in the present study and then its effect on biochemical indices in diabetic rats was evaluated. Diabetes was induced by high-fat diet consumption and streptozotocin (35 mg/kg) injection and then the treatment started 8 weeks after disease induction and continued for 8 weeks. The results showed that DIFc treatment decreased HOMA-IR index, blood urea nitrogen, uric acid and malondialdehyde in plasma samples. This nano MOF also reduced albumin, malondialdehyde and 8-isoprostane in urine specimen, while it increased creatinine clearance. In conclusion, DIFc MOF demonstrated promising results in the present study, indicating that it can be developed and evaluated in future investigations with the aim of designing a novel agent for management of diabetes and its renal complications.

The Impact of Surfactant Composition and Surface Charge of Niosomes on the Oral Absorption of Repaglinide as a BCS II Model Drug

Background

Niosomes, bilayer vesicles formed by the self-assembly of nonionic surfactants, are receiving increasing attention as potential oral drug delivery systems but the impact of niosomal formulation parameters on their oral capability has not been studied systematically. The aim of this study was to investigate the impact of surfactant composition and surface charge of niosomes in enhancing oral bioavailability of repaglinide (REG) as a BCS II model drug.

Methods

Niosomes (13 formulations) from various nonionic surfactants having HLB in the range of 4–28 (Tweens, Spans, Brijs, Myrj, poloxamer 188, TPGS and Labrasol) were prepared and characterized concerning their loading efficiency, hydrodynamic diameter, zeta potential, drug release profile, and stability. The oral pharmacokinetics of the selected formulations were studied in rats (8 in vivo groups).

Results

The results revealed that type of surfactant markedly affected the in vitro and in vivo potentials of niosomes. The C_max and AUC values of REG after administration of the selected niosomes as well as the drug suspension (as control) were in the order of Tween 80> TPGS> Myrj 52> Brij 35> Span 60≈Suspension. Adding stearyl amine as a positive charge-inducing agent to the Tween 80-based niosomes, resulted in an additional increase in drug absorption and values of AUC and C_max were 3.8- and 4.7-fold higher than the drug suspension, respectively.

Conclusion

Cationic Tween 80-based niosomes may represent a promising platform to develop oral delivery systems for BCS II drugs.

DIBc nano metal-organic framework improves biochemical and pathological parameters of experimental chronic kidney disease

BACKGROUND

The growing morbidity and mortality rate of chronic kidney disease (CKD) has forced researchers to find more efficient strategies for controlling this disease. Studies have proven the important role of alteration in iron, zinc and selenium metabolism in CKD pathological process. Nanotechnology, through synthetizing nano metal-organic framework (NMOF) structures, can be employed as a valuable strategy for using these trace elements as the key for modification and improvement of CKD-related pathological events. After proving the anti-diabetic property of DIBc NMOF (which contains selenium and zinc) in the previous study, the impact of this NMOF on some important biochemical and pathological parameters of CKD was evaluated in the current study.

METHODS

Knowing that diabetic nephropathy (DN) is the leading cause of CKD, male wistar rats were selected and given a high fat diet for 2 weeks and then were injected with streptozotocin (35 mg/kg) to induce DN. Six weeks after streptozotocin injection, DIBc or metformin treatment started and continued for 8 weeks.

RESULTS

Eight weeks of DIBc treatment decreased plasma fasting blood glucose, blood urea nitrogen, uric acid, malondialdehyde (MDA) and HOMA-IR index compared to DN control and metformin groups. This NMOF significantly reduced urinary albumin excretion rate, MDA and 8-isoprostane, while it increased creatinine clearance in comparison to the above-mentioned groups. Renal histo-pathological images indicated that DIBc ameliorated glomerular basement membrane thickening and wrinkling, mesangial matrix expansion and hypercellularity and presence of intra-cytoplasmic hyaline droplets in proximal cortical tubules of kidney samples.

CONCLUSION

The results showed the therapeutic effect of DIBc on important biochemical and histo-pathological parameters of CKD, so this NMOF could be regarded as a promising novel anti-CKD agent.

Nanoformulation strategies for improving intestinal permeability of drugs: A more precise look at permeability assessment methods and pharmacokinetic properties changes

The therapeutic efficacy of orally administered drugs is often restricted by their inherent limited oral bioavailability. Low water solubility, limited permeability through the intestinal barrier, instability in harsh environment of the gastrointestinal (GI) tract and being substrate of the efflux pumps and the cytochrome P450 (CYP) can impair oral drug bioavailability resulting in erratic and variable plasma drug profile. As more drugs with low membrane permeability are developed, new interest is growing to enhance their intestinal permeability and bioavailability. A wide variety of nanosystems have been developed to improve drug transport and absorption. Sufficient evidence exists to suggest that nanoparticles are able to increase the transepithelial transport of drug molecules. However, key questions remained unanswered. What types of nanoparticles are more efficient? What are preclinical (or clinical) achievements of each type of nanoformulation in terms of pharmacokinetic (PK) parameters? Addressing this issue in this paper, we have reviewed the current literature regarding permeability enhancement, permeability assessment methods and changes in PK parameters following administration of various nanoformulations. Although permeability enhancement by various nanoformulations holds great promise for oral drug delivery, many challenges still need to be addressed before development of more clinically successful nanoproducts.

BCc1 Nanomedicine Therapeutic Effects in Streptozotocin and High-Fat Diet Induced Diabetic Kidney Disease

BACKGROUND

One common feature of chronic diseases, such as cancer, diabetes and chronic kidney disease (CKD), is the disruption of iron metabolism and increase in labile iron pool, which can result in excessive production of harmful oxidative stress. The proper management of iron metabolism in this situation can be a valuable tool to ameliorate pathological events.

MATERIALS AND METHODS

In the previous studies, the anti-neoplastic effects of BCc1, a nanochelating-based nanomedicine with iron-chelating property, were demonstrated in cell culture, animal models and clinical trials. In the present study, the therapeutic effects of BCc1 in animal model of diabetic kidney disease (DKD), induced by streptozotocin injection (35 mg/kg) and high-fat diet consumption, were evaluated.

RESULTS

The results showed that BCc1 significantly decreased HOMA-IR index, uric acid, blood urea nitrogen, malondialdehyde and 8-isoprostane. In addition, it reduced urinary albumin excretion rate and albumin-to-creatinine ratio in comparison to DKD control rats. This nanomedicine had no negative impact on liver iron content, hemoglobin level, red blood cell count, hematocrit and mean corpuscular volume, while it significantly decreased aspartate aminotransferase and alanine aminotransferase compared to DKD control group. Moreover, the histopathological assessment indicated that lesser glomerular basement membrane and wrinkling, mesangial matrix expansion and pathological changes in proximal cortical tubules were seen in the kidney samples of BCc1-treated rats.

CONCLUSION

In conclusion, BCc1 as an iron-chelating agent shows promising impacts in DKD animal model, which can ameliorate biochemical and pathological events of this disease.

Green Formulation of Triglyceride/Phospholipid-Based Nanocarriers as a Novel Vehicle for Oral Coenzyme Q10 Delivery

This study was aimed to develop a novel nanocarrier for coenzyme Q10 (CoQ10) by a green process that prevented the use of surfactants and organic solvents. Triglyceride/phospholipid-based nanocarriers were developed through high-pressure homogenization (an industrial feasible process), and a 2^5-1 fractional factorial design was adopted to assess the influences of formulation variables on the considered responses, including vesicle size, entrapment efficiency, loading capacity, and solubility of the vehicles in simulated gastrointestinal fluids. The optimized formulation was further in-depth characterized in terms of morphology, release behavior, biocompatibility (Caco-2 cell cytotoxicity and histological examination), thermal behavior, and Fourier transform infrared analysis. Optimal nanocarriers were found to have mean particle size of 75 nm, narrow particle distribution, and CoQ10 entrapment of 95%. The optimized formulation was stable upon incubation in simulated gastrointestinal fluids without considerable leakage of cargo, which was in agreement with their sustained release behavior. Microscopic observations also confirmed nanosized nature of the vesicles and revealed their spherical shape. Moreover, toxicity evaluations at the cellular and tissue levels revealed their nontoxic nature. In conclusion, triglyceride/phospholipid-based nanocarriers proved to be a green safe vehicle for delivery of CoQ10 with industrial-scale production capability and could provide a new horizon for delivery of hydrophobic nutraceuticals. PRACTICAL APPLICATION: Green nanostructure formulation approaches have recently gained tremendous attraction for their safe profile especially when it comes to supplements, which are generally recommended for daily use. However, their sufficient association with cargoes and industrial-scale production have remained considerable challenges. This study focuses on the development of lipid-based nanocarriers for CoQ10 by an industrial feasible process that prevents the use of any surfactants or organic solvents.

Pharmacokinetics, Tissue Distribution and Excretion of Ag2S Quantum Dots in Mice and Rats: the Effects of Injection Dose, Particle Size and Surface Charge

PURPOSE

We systematically investigated the effects of injection dose, particle size and surface charge on the pharmacokinetics, tissue distribution and excretion of Ag₂S quantum dots (Qds) in rats and mice.

METHODS

Three different doses of Ag₂S Qds with similar size and composition were administrated to rats and mice. The effect of size and surface charge was investigated with the injection of three sizes (5, 15 and 25 nm) of Ag₂S Qds possessing similar surface charge, as well as 5 nm Qds with a positive surface charge.

RESULTS

Results indicated that pharmacokinetics and biodistribution of Ag₂S Qds were strongly dose, particle size and surface charge dependent. By increasing the dose from 0.5 to 4.0 mg/kg, mean residence time (MRT) and apparent volume of distribution at steady state (V_ss) were increased while clearance (CL) was decreased. Qds with a negative surface charge had significantly larger MRT and V_ss values than positively charged particles, but their CL was about 50% lower than that of positively charged ones. By increasing Qds size from 5 to 25 nm, CL was increased while MRT and AUC were decreased.

CONCLUSIONS

This study establishes comprehensive principles for the rational design and tailoring of Ag₂S Qds for biomedical applications. Graphical Abstract The effects of injection dose, particle size and surface charge on pharmacokinetics and tissue distribution of Ag₂S Qds after intravenous injection into rats and mice were investigated.

An Investigation into the Role of P-Glycoprotein in the Intestinal Absorption of Repaglinide: Assessed by Everted Gut Sac and Caco-2 Cell Line

The present study aimed at exploring the potential of the P-glycoprotein (P-gp) transporters as a barrier to the repaglinide (REG) epithelial permeability. In-vitro intestinal absorption models, the everted gut sac, and Caco-2 cell line, were used to study the possible role of P-gp in intestinal transport of REG. In the everted gut sacs, apparent permeability coefficients showed cargo concentration dependency transport over the concentration of 40 µM, indicating involvement of a saturable mechanism in REG absorption (P_app were 1.23 × 10 ^-5 and 3.29 × 10 ^-5 at drug concentrations of 40 and 100 μM, respectively). Adding verapamil (100 μM), valspodar (5 μM) and ketoconazole (10 μM) significantly enhanced the permeability of REG across mucosal to serosal in the rat jejunum (P < 0.05) suggesting role of CYP 3A4 and/or efflux transporters in oral bioavailability of REG. However, the results of Caco-2 cell experiments indicated low efflux ratios (less than 2) and insignificant involvement of P-gp efflux pumps in REG intestinal transport. Given that Caco-2 cells do not express adequate level of CYP 3A4, the current study suggests that the presystemic metabolism by cytochrome P450 (and not ejection by P-gp) may play a significant role in limiting the oral absorption of REG in small intestine.

Radiolabeling of Preformed Niosomes with [99mTc]: In Vitro Stability, Biodistribution, and In Vivo Performance

Nanocarriers radiolabeled with [^99mTc] can be used for diagnostic imaging and radionuclide therapy, as well as tracking their pharmacokinetic and biodistribution characteristics. Due to the advantages of niosomes as an ideal drug delivery system, in this study, the radiolabeling procedure of niosomes by [^99mTc]-HMPAO complexes was investigated and optimized. Glutathione (GSH)-loaded niosomes were prepared using a thin-film hydration method. To label the niosomes with [^99mTc], the preformed GSH-loaded niosomes were incubated with the [^99mTc]-HMPAO complex and were characterized for particle size, size distribution, zeta potential, morphology, and radiolabeling efficiency (RE). The effects of GSH concentration, incubation time, incubation temperature, and niosomal composition on RE were investigated. The biodistribution profile and in vivo SPECT/CT imaging of the niosomes and free [^99mTc]-HMPAO were also studied. Based on the results, all vesicles had nano-sized structure (160-235 nm) and negative surface charge. Among the different experimental conditions that were tested, including various incubation times, incubation temperatures, and GSH concentrations, the optimum condition that resulted in a RE of 92% was 200-mM GSH and 15-min incubation at 40°C. The in vitro release study in plasma showed that about 20% of radioactivity was released after 24 h, indicating an acceptable radiolabeling stability in plasma. The biodistribution of niosomes was clearly different from the free radiolabel. Niosomes carrying radionuclide were successfully used for tracking the in vivo disposition of these carriers and SPECT/CT imaging in rats. Furthermore, biodistribution studies in tumor-bearing mice revealed higher tumor accumulation of the niosomal formulation as compared with [^99mTc]-HMPAO.

Labrasol-Enriched Nanoliposomal Formulation: Novel Approach to Improve Oral Absorption of Water-Insoluble Drug, Carvedilol

The purpose of the current study was to develop a novel liposomal formulation to improve the oral bioavailability of carvedilol, a Biopharmaceutics Classification System class II with poor aqueous solubility and extensive presystemic metabolism. Conventional and various surfactant-enriched carvedilol-loaded liposomes were prepared by thin film hydration technique and physicochemical properties of liposomes (including size, encapsulation efficiency, release behavior, and morphology) were evaluated. To assess the oral bioavailability, in vivo studies were carried out in eight groups of male Wistar rats (n = 6) and the drug plasma concentration was determined. Conventional and surfactant containing liposomes showed average particle size of 76-104 nm with a narrow size distribution, high encapsulation efficiency (80%≤) and a sustained release profile in simulated intestinal fluid. Compared to the suspension, conventional and Labrasol containing liposomes significantly improved the oral bioavailability and peak plasma concentration of carvedilol. Biocompatibility studies (cell cytotoxicity and histopathological analyses) showed that the enhancing effect might be achieved without any apparent toxicity in the intestine. Decreased oral absorption of carvedilol nanovesicles by using a chylomicron flow blocker indicated contribution of lymphatic transport in nanocapsules absorption. The results reported the successful development of biocompatible Labrasol-enriched carvedilol nanoliposomal formulation with a significant oral enhancement capability. Graphical Abstract ᅟ.

Theranostic niosomes for direct intratumoral injection: marked enhancement in tumor retention and anticancer efficacy

AIM

For simultaneous bioimaging and drug delivery via direct intratumoral injection, doxorubicin and Ag₂S quantum dots co-loaded multifunctional niosomes were prepared and fully characterized.

MATERIALS & METHODS

Various theranostic niosomes were prepared and investigated regarding cytotoxicity, in vivo imaging, drug accumulation in breast cancer tumor and antitumor activity.

RESULTS

Niosomes composed of Tween-60, Tween-80 or Span 60 produced strong and more durable detectable fluorescence signals. Despite a higher accumulation of Tween-60 niosomes in tumor, the Span 60 formulation showed the highest antitumor efficacy when compared with the free drug (71.7 and 20.3% inhibition in tumor growth, respectively).

CONCLUSION

Direct intratumoral injection of theranostic niosomes with appropriate composition could be a powerful tool for combined multimodal imaging and therapy.

Controlled SLN Delivery by Thermoresponsive In-situ Forming Erodible Gels; A Whole-body and Organ Imaging Study

BACKGROUND

Nanoparticles (NPs) suffer from rapid clearance from body and require frequent dosing if long treatment is required.

METHOD

In order to solve this problem for solid lipid nanoparticles (SLN) and prolong their action, SLNs were incorporated into thermo-responsive Poloxamer sol-gels and their fate was investigated invivo and in-vitro using a near infrared lipophilic fluorescent dye; dialkylcarbocyanin [1]. Leakage test, release of intact SLNs from sol-gel and SLN size and zeta potential were investigated. Biodistribution of DiR formulations (solution, free SLN and SLN-Gel) was investigated by whole-body and ex-vivo organ imaging after intraperitoneal injection in mice. SLN showed particle size of about 165 nm and a negative zeta potential of about -36 mV.

RESULTS

Leakage studies indicated that fluorescent probe does not release from SLNs. Imaging results revealed a steady profile for SLN-Gel over time, while the fluorescence intensity of solution and free SLN showed a burst followed by rapid clearance. Results also showed that SLN release occurs after gel erosion and follows a zero order profile.

CONCLUSION

Our results indicate that NP-incorporated gel can be used to control the release of SLNs from application site and prolong their action in a sustained manner.

Physicochemical, Stress Degradation Evaluation and Pharmacokinetic Study of AZGH101; a New Synthesized COX2 Inhibitor after I.V. and Oral Administration in Male and Female Rats

Nonsteroidal anti-inflammatory drugs (NSAIDs) act mainly via inhibition of prostaglandins synthesis by inhibition of cyclooxygenase (COX) isoenzymes (COX-1 and COX-2). Selective COX-2 inhibitors which are also known as coxibs provide the main therapeutic effects of NSAIDs. Zarghi et al. reported 6-benzoyl-2-(4-(methylsulfonyl) phenyl) quinoline-4-carboxylic acid (AZGH101) as a novel derivative of ketoprofen with improved selectivity index (COX-1/COX-2 inhibitory potency) in comparison with ketoprofen. In this study, the log P and stability of AZGH101 were evaluated and the pharmacokinetic characteristics of this compound were investigated following intravenous (10 mg/kg), and oral administration (20 mg/kg), to Wistar rats. As the data demonstrated, the AZGH101was classified as lipid soluble compound and had suitable stability according to forced degradation protocol ICH guideline for new drug substance. This derivative absorbs, distributes, and eliminates similar in both sexes. The AUC 0-∞, absolute bioavailability, Cl, and Vd were not different in both sexes. According to the obtained data, the AZGH101 does not have a sex dependent pharmacokinetic in Wistar rats.

Administration of Vancomycin at High Doses in Patients with Post Neurosurgical Meningitis: A Comprehensive Comparison between Continuous Infusion and Intermittent Infusion

Poor penetration of vancomycin into Central Nervous System (CNS) can lead to treatment failure. The aim of this study was to evaluate and compare CSF concentration and serum pharmacokinetics of high dose vancomycin by continuous infusion vs. intermittent infusion in post neurosurgical meningitis patients. Twenty patients were divided into two groups. Patients in intermittent infusion group received vancomycin as a loading dose of 25 mg/kg over two hours, followed by 25 mg/kg over two hours every 12 h. In the Continuous Infusion group, patients received vancomycin as a loading dose of 25 mg/kg over two hours, followed by 50 mg/kg/day by continuous infusion. In the intermittent infusion group, mean ± SD of serum trough, peak and CSF concentrations were 17.49 ± 2.46 mg/L, 41.33 ± 2.73 mg/L, and 4.83 ± 1.05 mg/L, respectively. Mean of CSF/trough% ratio was 27.39 ± 2.43%. A positive linear correlation was found between the serum trough levels and CSF levels (r = 0.970, P < 0.001). In continuous infusion group, mean ± SD of serum and CSF concentrations were 24.76 ± 2.02 mg/L and 6.20 ± 1.31 mg/L respectively. Mean ± SD of CSF/serum% ratio was 24.84% ± 3.54%. The serum and CSF levels revealed positive linear correlation (r = 0.902, P < 0.001). The mean of CSF concentration in CI group was 6.20 ± 1.31 mg/L which was significantly higher than II group (4.83 ± 1.05 mg/L, P < 0.019). CSF/serum ratio did not show any significant difference between the two groups. Continuous infusion of vancomycin makes it possible to achieve faster and constant target level in serum but did not have any significant effect on the penetration (CSF/Serum ratio) of vancomycin in to the CNS.

Preparation, In-Vitro Characterization and Pharmacokinetic Evaluation of Brij Decorated Doxorubicin Liposomes as a Potential Nanocarrier for Cancer Therapy

The aim of current study was to investigate the effect of Brij decoration of liposomes on in-vitro and in-vivo characteristics of the nanocarriers. Two hydrophilic Brij surfactants (Brij 35 and Brij 78) with almost similar molecular weight but differing in acyl chain were incorporated into liposomal bilayers at two percentages (5% and 10%). Conventional liposomes (CL) containing egg phosphatidylcholine and cholesterol as well as Brij-enriched liposomal dispersions were prepared and characterized. In-vivo pharmacokinetics of various liposomal formulations and drug solution (six groups) was studied after intravenous administration to rats. Conventional and Brij enriched doxorubicin (DOX) liposomes had small size within 82-97 nm and showed homogenous distribution (PDI < 0.1). Drug encapsulation was higher than 97% in all liposomes. The drug release profiles proved sustained DOX release from various formulations. Based on the results of in-vivo studies, all five liposomes increased drug exposure and plasma concentration in comparison to free drug. However, DOX liposomes enriched with 5% of either Brij 35 or Brij 78 showed higher AUC values and lower clearance. Overall, Brij surfactants (5% of bilayer lipids) could be potentially used to improve liposomal pharmacokinetic parameters.

Potential of Liposomes for Enhancement of Oral Drug Absorption

Oral administration of medication is the first option when patient compliance is considered. However, many barriers face oral absorption of drugs that limit bioavailability in about 90% of therapeutic agents. Utilization of nanoparticulate drug delivery systems is a major strategy for increasing oral absorption. They can improve oral bioavailability through mechanisms such as protection of the drug in the GI tract, increasing cellular contact and residence time of the drug, protection of the drug from presystemic metabolism and efflux and increasing diffusion across the mucosal and epithelial layers. Liposomes are biocompatible carriers employed to improve oral bioavailability of drugs and in addition to the general advantages of nanocarriers for oral delivery, they offer benefits derived from their lipidic bilayer structure. They can better adhere to biomembranes, form mixed-micelle structures with bile salts to increase the solubility of poorly-soluble drugs and are suitable candidates for lymphatic uptake. They have been successful in improving oral bioavailability of a variety of compounds including peptide and proteins, hydrophilic and lipophilic drugs. Stability under GI conditions is the main concern for oral liposomes, however, promising approaches have been suggested to increase the stability of oral liposomes. These include: using appropriate lipid compositions, polymer coating, addition of stabilizing lipids to liposomal structures, preparation of double liposomes and proliposomes and some other innovative methods. The present review focuses on the role of liposomes in improving oral absorption of drugs, the problems encountered, and the types of liposomes designed to overcome these issues. Barriers to oral delivery will be discussed and examples of bioavailability enhancement upon encapsulation in various types of liposomes investigated.

Doxorubicin-loaded liposomes: enhancing the oral bioavailability by modulation of physicochemical characteristics

Aim: In this study, the effects of liposome characteristics on oral absorption of doxorubicin, as a hydrophilic low-permeability drug, were investigated. Materials & methods: Different doxorubicin-loaded liposomes were prepared, characterized and orally administered to 18 groups of rats. Plasma concentrations of doxorubicin and its aglycone metabolite were measured, and Caco-2 uptake and transport of optimum liposomes were investigated. Results: After studying different factors, a fourfold increase in oral bioavailability was achieved with the non-PEGylated, 120-nm-sized positively charged rigid liposomes (lipid to drug ratio = 10). The extent of drug’s first-pass metabolism as well as endocytosis of nanoparticles were markedly affected by liposomal formulation. Conclusion: Oral absorption is highly dependent on liposomal properties, and optimum formulations are effective for low-permeability drugs.

State of the Art of Stimuli-Responsive Liposomes for Cancer Therapy

Specific delivery of therapeutic agents to solid tumors and their bioavailability at the target site are the most clinically important and challenging goals in cancer therapy. Liposomes are promising nanocarriers and have been well investigated for cancer therapy. In spite of preferred accumulation in tumors via the enhanced permeability and retention (EPR) effect, inefficient drug release at the target site and endosomal entrapment of long circulating liposomes are very important obstacles for achieving maximum anticancer efficacy. Thus, additional strategies such as stimulus-sensitive drug release are necessary to improve efficacy. Stimuli-sensitive liposomes are stable in blood circulation, however, activated by responding to external or internal stimuli and control the cargo release at the target site. This review focuses on state of the art of stimuli-responsive liposomes. Both external stimuli-responsive liposomes, including hyperthermia (HT), magnetic, light, and ultrasound-sensitive liposomes and internal stimuli (pH, reduction, and enzyme) responsive liposomes are covered.

Enhanced Dissolution Rate of Tadalafil Nanoparticles Prepared by Sonoprecipitation Technique: Optimization and Physicochemical Investigation

Nanocrystals of tadalafil, a poorly water-soluble drug, were successfully prepared by sonoprecipitation technique for improving the solubility and dissolution rate. Tween 80 was selected as an efficient surfactant to inhibit aggregation in stabilization of drug nanocrystals. Response surface methodology based on central composite design (CCD) was utilized to evaluate the formulation factors affecting the size of nanosuspensions. Under optimum conditions, relatively spherical nanocrystals with a mean particle size of 358.47 ± 11.95nm were obtained. FTIR analysis indicated that the precipitated nanoparticles had the same chemical structure as the raw tadalafil. By DSC analysis, no substantial crystalline change was found in the nanocrystals compared with the unprocessed drug. In addition, the dissolution rate of the processed tadalafil nanocrystals in 120 min was significantly increased (3.61-fold) as compared to that of the raw material. Therefore, it was concluded that the sonoprecipitation technique could be a simple and useful technique to prepare poorly water-soluble drug particles with reduction in particle size, a narrow particle size distribution and enhanced dissolution properties.

Dorzolamide Loaded Niosomal Vesicles: Comparison of Passive and Remote Loading Methods

Glaucoma is a common progressive eye disorder and the treatment strategies will benefit from nanoparticulate delivery systems with high drug loading and sustained delivery of intraocular pressure lowering agents. Niosomes have been reported as a novel approach to improve drug low corneal penetration and bioavailability characteristics. Along with this, poor entrapment efficiency of hydrophilic drug in niosomal formulation remains as a major formulation challenge. Taking this perspective into consideration, dorzolamide niosomes were prepared employing two different loading methodologies (passive and remote loading methods) and the effects of various formulation variables (lipid to drug ratio, cholesterol percentage, drug concentration, freeze/thaw cycles, TPGS content, and external and internal buffer molarity and pH) on encapsulation efficiency were assessed. Encapsulation of dorzolamide within niosomes increased remarkably by the incorporation of higher cholesterol percentage as well as increasing the total lipid concentration. Remote loading method showed higher efficacy for drug entrapment compared to passive loading technique. Incorporation of TPGS in bilayer led to decrease in EE; however, retarded drug release rate. Scanning electron microscopy (SEM) studies confirmed homogeneous particle distribution, and spherical shape with smooth surface. In conclusion, the highest encapsulation can be obtained using phosphate gradient method and 50% cholesterol in Span 60 niosomal formulation.

Physicochemical, Stress Degradation Evaluation and Pharmacokinetic Study of AZGH102, a New Synthesized COX2 Inhibitors after I.V. and Oral Administration in Male and Female Rats

Coxibs such as celecoxib, rofecoxib, and valdecoxib are introduced as selective COX-2 inhibitors to the market. It has been reported that inhibition of COX-2 beside traditional effects of NSAIDs, reduces the risk of colorectal, breast and lung cancers and also slow the progress of Alzheimer's disease. Zarghi et al. reported 8-benzoyl-2-(4-(methylsulfonyl)phenyl)quinoline-4-carboxylic acid (AZGH 102) as a novel compound with similar IC50 to celecoxib besides improved selectivity index (COX-1/COX-2 inhibitory potency) in comparison with celecoxib. In this study, the physicochemical properties of AZGH 102 such as solubility, log P, and stability were evaluated and the pharmacokinetic characteristics of this compound following intravenous (10 mg/Kg), and oral administration (20 mg/Kg), to male and female Wistar rats were investigated. As the data demonstrated, the AZGH 102 classified as lipophil compound and had suitable stability. This derivative absorbs and distributes faster in female than in male. The AUC 0-∞, absolute bioavailability, Cl and Vd were different in both sexes. According to the obtained data, the AZGH 102 has a sex dependent pharmacokinetic in Wistar rats.

Physicochemical characteristics of liposomes are decisive for their antirestenosis efficacy following local delivery

AIM

To develop an ameliorated sirolimus (SIR) liposome for intramural delivery, the effects of various carrier physicochemical parameters on the antirestenosis efficacy were evaluated.

MATERIALS & METHODS

Different liposomes were prepared, characterized and administered to balloon injured rats (12 animal groups). Their efficacies were investigated using morphometric, immunohistochemical and in vivo computed tomography imaging analyses.

RESULTS

The antirestenosis efficacy of SIR liposomes decreased in the following order: cationic 100 nm vesicles ≥ cationic 60 nm vesicles > neutral 100 nm vesicles ≥ stealth 100 nm vesicles > anionic 100 nm vesicles. The 100 µg SIR loaded in cationic liposomes showed almost no artery stenosis.

CONCLUSION

Appropriate modulation of physicochemical characteristics makes it possible to optimize the liposomes for local delivery.