An injectable thermosensitive hydrogel/nanomicelles composite for local chemo-immunotherapy in mouse model of melanoma.

Recently, cancer immunotherapy and its combination with chemotherapy has been considered to improve therapeutic efficacy with lower systemic toxicity. Here, we prepared a thermosensitive hydrogel based hyaluronic acid (HA) encapsulated with macrophage colony-stimulating factor (GM-CSF) and paclitaxel (PTX) for chemoimmunotherapy of cancer. For this purpose, the micelles were prepared with the mixture of pluronic F127 (PF127) and tocopheryl polyethylene glycol (TPGS) and loaded with PTX. In the following step, thermosensitive hydrogel using PF127 and HA was prepared and co-encapsulated with the micelles and GM-CSF. Rheological performance, friability, release patterns for PTX and GM-CSF, and stability of GM-CSF in the hydrogel were evaluated in details. In-vitro and in vivo immunologic activities of GM-CSF in the hydrogel were also evaluated via numbering macrophages and recruited DCs in transwells and after subcutaneous injection of the GM-CSF-loaded hydrogel. Finally, mouse model of subcutaneous melanoma was induced in female C57 mice using B16 F10 cell line and the effect of optimized formulation was evaluated based on tumor volume and histological analysis. The hydrogel could maintain the biological activity of the incorporated drugs and exhibited a more prolonged release for PTX compared to GM-CSF. GM-CSF-releasing HA/PF127 hydrogel successfully recruited macrophages in vitro. Moreover, the most potent anti-tumor effect was observed following the intra-tumoral injection of the optimized formulation in melanoma bearing mice, compared to immunization by the GM-CSF and PTX alone. The current formulation shows a great promise to conquer resistant malignancies and provides a new approach for co-encapsulating of hydrophobic anticancer drugs and growth factor.

Pulmonary Delivery of Docetaxel and Celecoxib by PLGA Porous Microparticles for Their Synergistic Effects Against Lung Cancer.

BACKGROUND: Using a combination of chemotherapeutic agents with novel drug delivery platforms to enhance the anticancer efficacy of the drug and minimizing the side effects, is imperative to lung cancer treatments. OBJECTIVE: The aim of the present study was to develop, characterize, and optimize porous poly (D, L-lactic-co-glycolic acid) (PLGA) microparticles for simultaneous delivery of docetaxel (DTX) and celecoxib (CXB) through the pulmonary route for lung cancer. METHODS: Drug-loaded porous microparticles were prepared by an emulsion solvent evaporation method. The impact of various processing and formulation variables including PLGA amount, dichloromethane volume, homogenization speed, polyvinyl alcohol volume, and concentration, was assessed based on entrapment efficiency, mean release time, particle size, mass median aerodynamic diameter, fine particle fraction, and geometric standard deviation using a twolevel factorial design. An optimized formulation was prepared and evaluated in terms of size and morphology using a scanning electron microscope. RESULTS: FTIR, DSC, and XRD analyses confirmed drug entrapment and revealed no drug-polymer chemical interaction. Cytotoxicity of DTX along with CXB against A549 cells was significantly enhanced compared to DTX and CXB alone and the combination of DTX and CXB showed the greatest synergistic effect at a 1/500 ratio. CONCLUSION: In conclusion, the results of the present study suggest that encapsulation of DTX and CXB in porous PLGA microspheres with desirable features is feasible and their pulmonary co-administration would be a promising strategy for the effective and less toxic treatment of various lung cancers.

Development and validation of a new robust RP-HPLC method for simultaneous quantitation of insulin and pramlintide in non-invasive and smart glucose-responsive microparticles.

Background and purpose: Since insulin and pramlintide cooperate in glucose hemostasis, co-administration and quantitation of them in pharmaceutical preparations are imperative. A simple, rapid, sensitive, and isocratic RP-HPLC method was developed and validated for simultaneous quantitation of insulin and pramlintide in loading and in-vitro release studies of a glucose-responsive system to improve the control of hyperglycemic episodes in diabetic patients. Experimental approach: The isocratic RP-HPLC separation was achieved on a C18 µ-Bondopak column (250 mm × 4.6 mm) using a mobile phase of water:acetonitrile:trifluoroacetic acid (65:35:0.1%) at a flow rate of 1 mL/min in an ambient temperature. Both proteins were detected using a UV detector at 214 nm. The method was validated for specificity, linearity, precision, accuracy, the limit of detection, the limit of quantification, and robustness. Findings/Results: Linearity was obtained in the concentration range of 30 to 360 µg/mL for insulin and 1.5 to 12 µg/mL for pramlintide. The results were validated statistically and recovery studies confirmed the great accuracy and precision of the proposed method. The robustness of the method was also confirmed through small changes in pH, mobile phase composition, and flow rate. Conclusion and implications: The method was found to be simple, specific, precise, and reproducible. It was applied for the determination of loading capacity, entrapment efficiency, and in-vitro release studies of insulin and pramlintide in a smart glucose-responsive microparticle. Co-delivery of insulin and pramlintide could be a new intervention in diabetes management and concurrent quantitation of these two proteins is, therefore, essential.

Design and evaluation of albumin nanoparticles for the delivery of a novel ß-tubulin polymerization inhibitor.

PURPOSE: The ultimate goal of this study is to develop a novel delivery system for a new potent cytotoxic compound, CCI-001, with anti-b tubulin activity, so that the drug can be effectively administered and at the same time its harmful side effects can be reduced. METHODS: In the current study, CCI-001 was loaded into serum albumin (SA), using a modified desolvation method, generating CCI-001-SA nanoparticles. Both bovine and human SA were used for the encapsulation of this drug candidate. Optimum conditions for drug loading were achieved when already formed and crosslinked albumin nanoparticles were incubated overnight at 37°C with CCI-001 solutions. The CCI-001-loaded albumin nanoparticles were assessed for average particle diameter and polydispersity, zeta potential, drug loading, in vitro release, morphology and cell toxicity against SW620 and HCT116 colorectal cancer cells. RESULTS: The spherical nanoparticles obtained were negatively charged (~ -30 mV) and had an average diameter of ~ 130 nm, with a narrow size distribution. The in vitro release of CCI-001 from the albumin nanoparticles showed a sustained release pattern over 24 hours without any initial burst release, compared to the fast release of the free drug under experimental conditions. No difference between the SA from the two species in terms of CCI-001 loading was observed. However, a significant difference was observed between the release profiles of CCI-001 from drug-loaded HSA and drug-loaded BSA nanoparticles with HSA nanoparticles showing slower drug release (mean release time, MRT, values of 5.14 ± 0.33 h and 6.88 ± 0.15 h for BSA-NPs and HSA-NPs, respectively, P < 0.01). Cellular toxicity studies showed higher cytotoxicity for CCI-001-SA compared to the free drug (IC50s of 0.62 ± 0.31 nM vs 2.06 ± 0.29 nM in SW620 cells and 0.9 ± 0.1 nM vs 4.2 ± 0.2 nM in HCT116 cells, for CCI-001-HSA NPs and free drug, respectively). Therefore, despite the low drug content level in the HSA nanoparticles of CCI-001, the formulation provides relevant concentrations for further in vivo studies in animal models due to high drug potency. CONCLUSIONS: The data support the potential use of albumin as a nanocarrier for CCI-001 in biological systems.

The Uniqueness of Albumin as a Carrier in Nanodrug Delivery.

Albumin is an appealing carrier in nanomedicine because of its unique features. First, it is the most abundant protein in plasma, endowing high biocompatibility, biodegradability, nonimmunogenicity, and safety for its clinical application. Second, albumin chemical structure and conformation allows interaction with many different drugs, potentially protecting them from elimination and metabolism in vivo, thus improving their pharmacokinetic properties. Finally, albumin can interact with receptors overexpressed in many diseased tissues and cells, providing a unique feature for active targeting of the disease site without the addition of specific ligands to the nanocarrier. For this reason, albumin, characterized by an extended serum half-life of around 19 days, has the potential of promoting half-life extension and targeted delivery of drugs. Therefore, this article focuses on the importance of albumin as a nanodrug delivery carrier for hydrophobic drugs, taking advantage of the passive as well as active targeting potential of this nanocarrier. Particular attention is paid to the breakthrough NAB-Technology, with emphasis on the advantages of Nab-Paclitaxel (Abraxane), compared to the solvent-based formulations of Paclitaxel, i.e., CrEL-paclitaxel (Taxol) in a clinical setting. Finally, the role of albumin in carrying anticancer compounds is depicted, with a particular focus on the albumin-based formulations that are currently undergoing clinical trials. The article sheds light on the power of an endogenous substance, such as albumin, as a drug delivery system, signifies the importance of the drug vehicle in drug performance in the biological systems, and highlights the possible future trends in the use of this drug delivery system.

In Vitro and In Vivo Evaluation of Two Hydroxychloroquine Tablet Formulations: HPLC Assay Development.

The relative in vitro and in vivo evaluation of two hydroxychloroquine (HCQ) products was conducted. In vitro studies involved assay, content uniformity and dissolution test, and a two-way crossover fashion were used for in vivo studies. Blood samples were collected at appropriate intervals and HCQ levels were measured using a validated reversed-phase high-performance liquid chromatography (HPLC) method. The drug and the internal standard, chloroquine (CQ), were extracted from blood with diethyl ether, separated and dried under nitrogen gas. Residues were reconstituted in the mobile phase and analyzed at 340 nm on a µ-bondapack C18 (250 × 4.6 mm) HPLC column with acetonitrile:methanol:KH2PO4 (10:10:80) mixture containing 0.01% triethylamine. The standard curve was linear within 50-1,500 ng/mL HCQ (R2 = 0.9996), relative errors were 1.6 to 5%, and the CV% ranged from 7 to 15.4. The resolution factor and RSD were 1.62 and 0.35% and in vitro data of both products met the USP requirements. The 90% confidence intervals for the ratios of the AUC0-96, Cmax and Tmax and their corresponding logarithmically transformed values of generic product over those of Plaquenil® were within the acceptable limit of 0.80-1.20 and 0.80-1.25, respectively. Therefore, the generic HCQ was bioequivalent to the innovator formulation.

In Vitro and In Vivo Evaluation of Novel DTX-Loaded Multifunctional Heparin-Based Polymeric Micelles Targeting Folate Receptors and Endosomes.

BACKGROUND: The development of biocompatible tumor-targeting delivery systems for anticancer agents is essential for efficacious cancer chemotherapy. Nanoparticles, as drug delivery cargoes for cancer therapy, are rapidly improving to overcome the limitations of conventional chemotherapeutic agents. Heparin-modified nanoparticles are currently being considered as one of the favorable carriers for the delivery of chemotherapeutics to cancer tissues. OBJECTIVE: This study was aimed at evaluating the in vitro and in vivo antitumor activity of a novel targeted, pH-sensitive, heparin-based polymeric micelle loaded with the poorly water-soluble anticancer drug, docetaxel (DTX). The micelles could overcome the limited water solubility, non-specific distribution, and insufficient drug concentration in tumor tissues. METHODS: DTX-loaded folate targeted micelles were prepared and evaluated for physicochemical properties, drug release, in vitro cellular uptake and cytotoxicity in folate receptor-positive and folate receptor-negative cells. Furthermore, the antitumor activity of DTX-loaded micelles was evaluated in the tumor-bearing mice. Some related patents were also studied in this research. RESULTS: The heparin-based targeted micelles exhibited higher in vitro cellular uptake and cytotoxicity against folate receptor over-expressed cells due to the specific receptor-mediated endocytosis. DTX-loaded micelles displayed greater antitumor activity, higher anti-angiogenesis effects, and lower systemic toxicity compared with free DTX in a tumor-induced mice model as confirmed by tumor growth monitoring, immunohistochemical evaluation, and body weight shift. DTX-loaded targeting micelles demonstrated no considerable toxicity on major organs of tumor-bearing mice compared with free DTX. CONCLUSION: Our results indicated that DTX-loaded multifunctional heparin-based micelles with desirable antitumor activity and low toxicity possess great potential as a targeted drug delivery system in the treatment of cancer.

Simultaneous Determination of Docetaxel and Celecoxib in Porous Microparticles and Rat Plasma by Liquid-Liquid Extraction and HPLC with UV Detection: in vitro and in vivo Validation and Application.

PURPOSE: A simple, rapid, sensitive, and reliable HPLC method with UV detection was developed and validated for simultaneous quantitation of docetaxel and celecoxib and paclitaxel for dissolution characterization and pharmacokinetic studies. METHODS: The HPLC assay was performed isocratically on a reversed-phase C18 µ-Bondapack column using a mobile phase of acetonitrile:water (45:55, v/v) at a flow rate of 1.2 mL/min, and the analytes were detected at 230 nm. Paclitaxel was used as an internal standard for analysis of plasma samples following simple liquid-liquid extraction with n-hexane:isoamyl alcohol (97:3). The method was validated for specificity, linearity, sensitivity, precision, accuracy, robustness, and in vitro-in vivo application. RESULTS: The retention times for docetaxel, paclitaxel, and celecoxib were 10.94, 12.4, and 16.81 min, respectively. The standard curves covering 0.1-1 µg/mL and 0.05-4 µg/mL were linear using dissolution medium and rat plasma, respectively. The limit of quantitation of the method was 50 ng/mL using 100 µL of rat plasma sample and injection of 50 µL of the residue. Within- and between-day precision and accuracy did not exceed 16.86% and 12.10%, respectively. This validated method was successfully used to quantify docetaxel and celecoxib simultaneously in the release study of docetaxel- celecoxib -loaded porous microparticles and pharmacokinetics studies. The methods were found to be simple, specific, precise, accurate, and reproducible. In this study, paclitaxel was used as the internal standard while dexamethasone, flutamide, and budesonide proved suitable alternative as an internal standard. CONCLUSION: Since docetaxel and celecoxib could be co-administered for the treatment of a wide range of cancers such as non-small cell lung carcinoma, the developed method is particularly advantageous for routine therapeutic drug monitoring and pharmacokinetic studies of these drugs.

Development of a RP-HPLC method for analysis of docetaxel in tumor-bearing mice plasma and tissues following injection of docetaxel-loaded pH responsive targeting polymeric micelles.

BACKGROUND AND PURPOSE: A simple, rapid, and sensitive reversed-phase high performance liquid chromatography (RP-HPLC) method based on liquid-liquid extraction was developed and validated for determination of docetaxel (DTX) in plasma and homogenate tissues of tumor-bearing mice. EXPERIMENTAL APPROACH: Samples were spiked with celecoxib as the internal standard and separation was achieved on a µ-Bondapak C18 HPLC column. The mobile phase consisted of a mixture of acetonitrile/water (40/60 v/v) at flow rate of 1.2 mL/min and the effluent was monitored at 230 nm. RESULTS: Calibration curves were linear over the concentration range of 0.1-10 µg/mL of DTX in plasma and 0.25-50 µg/mL in tissue homogenates with acceptable precision and accuracy. The mean recoveries of the drug from plasma extraction was 94.6 ± 1.44% while those of tissue homogenates ranged from 73.5 ± 3.2 to 85.3 ± 2.8% depending on the type of tissues examined. DTX was stable in biological samples with no evidence of degradation during 3 freeze-thaw cycles and two months of storage at -70 ± 15 °C. The developed HPLC method was applied to quantify DTX in the mouse plasma and tissues after intravenous administration of 7.5 mg equivalent DTX/kg dose of DTX-loaded folic acid-polyethylene glycol-heparin-tocopherol (FA-PEG-HEP-CA-TOC) micelle formulation to female Balb/c mice. CONCLUSION: A simple, sensitive, rapid, accurate, and prudent RP-HPLC method was developed, validated, and applied for DTX determination in plasma and tissues.

Novel pH-triggered biocompatible polymeric micelles based on heparin-α-tocopherol conjugate for intracellular delivery of docetaxel in breast cancer.

In this study, pH-triggered polymeric micelle comprising α-tocopherol (TOC) and heparin (HEP) was developed and loaded with docetaxel (DTX). The amphiphilic copolymer was synthesized by grafting TOC onto HEP backbone by a pH-cleavable bond. DTX-loaded micelles were characterized in terms of critical micelle concentration (CMC), particle size, zeta potential, entrapment efficiency (EE), pH-responsive behavior, and drug release. In vitro cytotoxicity of the micelles against breast cancer cells was investigated by MTT assay. The cellular uptake of coumarin-loaded micelles was also evaluated. Furthermore, the pharmacokinetics of DTX-loaded micelles was evaluated and compared with that of Taxotere®.HEP-CA-TOC copolymers showed low CMC values and high EE. At pH 7.4, the micelles remained stable in size and shape, whereas considerable changes in particle size and morphology were observed at pH 5.5. DTX-loaded micelles showed pH-dependent drug release profiles. Coumarin-loaded micelles showed higher cellular uptake than free coumarin. Therefore, the DTX-loaded micelles showed more toxicity against breast cancer cells than free DTX. A significant increase in T1/2 ß, AUC0-∞ and MRT was observed in DTX-loaded micelle treated group as compared to the group treated with Taxotere®.The results suggest that the pH-sensitive HEP-modified micelles could be promising for enhanced intracellular drug delivery of DTX for cancer treatment.

Therapeutic drug monitoring of vancomycin by AUCτ-MIC ratio in patients with chronic kidney disease.

In this study which was conducted in Alzahra University Hospital (Isfahan, I.R. Iran), the therapeutic drug monitoring of vancomycin focused on determining area under the concentration-time curve at dosing interval (τ) at steady state/minimum inhibitory concentration (AUCτ/MIC) was carried out in chronic kidney disease (CKD) patients. The study population was selected from patients with the history of CKD (stages 3 or 4) treated by intravenous vancomycin. To determine vancomycin AUCτ, blood samples were taken at four different occasions (trough-1, peak, random, trough-2) between the fourth and fifth doses of vancomycin. Drug concentration was determined by fluorescence polarization technique, and the E-TEST technique was used to determine the MIC. Nineteen patients were included. For 8 (42%), 7 (37%), and 4 (21%) patients, trough concentration levels were found to be less than 10 mg/L, 10-20 mg/L, and more than 20 mg/L, respectively. The mean value of AUCτ for studied patients was 470.7 ± 228.3 mg.h/L and the mean MIC values was 1.04 ± 0.43 mg/L. Ten patients (53%) and 9 patients (47%) had the AUCτ/MIC ratios above 400 and below 400, respectively, with the average of 519.4 ± 391.3 h. Vancomycin dosing based on patient glomerular filtration rate (GFR), as a traditional method, is not accurate enough to gain the most desired vancomycin concentration in patients with decreased or changing kidney function. Measuring drug concentration and observing its therapeutic effects accordingly is inevitable in susceptible populations receiving vital drugs such as vancomycin.

Receptor targeting drug delivery strategies and prospects in the treatment of rheumatoid arthritis.

Rheumatoid arthritis (RA), a chronic inflammatory disease, is characterized by cartilage damage, bone tissue destruction, morphological changes in synovial fluids, and synovial joint inflammation. The inflamed synovial tissue has potential for passive and active targeting because of enhanced permeability and retention effect and the existence of RA synovial macrophages and fibroblasts that selectively express surface receptors such as folate receptor ß, CD44 and integrin αVß. Although there are numerous interventions in RA treatment, they are not safe and effective. Therefore, it is important to develop new drug or drug delivery systems that specifically targets inflamed/swollen joints but attenuates other possible damages to healthy tissues. Recently some receptors such as toll-like receptors (TLRs), the nucleotide-binding oligomerization domain-like receptors, and Fc-γ receptor have been identified in synovial tissue and immune cells that are involved in induction or suppression of arthritis. Analysis of the TLR pathway has moreover suggested new insights into the pathogenesis of RA. In the present paper, we have reviewed drug delivery strategies based on receptor targeting with novel ligand-anchored carriers exploiting CD44, folate and integrin αVß as well as TLRs expressed on synovial monocytes and macrophages and antigen presenting cells, for possible active targeting in RA. TLRs could not only open a new horizon for developing new drugs but also their antagonists or humanized monoclonal antibodies that block TLRS specially TLR4 and TLR9 signaling could be used as targeting agents to antigen presenting cells and dendritic cells. As a conclusion, common conventional receptors and multifunctional ligands that arte involved in targeting receptors or developing nanocarriers with appropriate ligands for TLRs can provide profoundly targeting drug delivery systems for the effective treatment of RA.

Preparation and Characterization of Spray-Dried Inhalable Powders Containing Polymeric Micelles for Pulmonary Delivery of Paclitaxel in Lung Cancer.

PURPOSE: Local delivery of chemotherapeutic drugs to the lungs offers many advantages for lung cancer treatment compared to conventional systemic chemotherapy. In the present study, novel mixed polymeric micelles based on tocopheryl succinate-polyethylene glycol 1000 and 5000 Da (TPGS1K and TPGS5K) were synthesized and loaded with paclitaxel (PTX). Then, the optimized micelles were incorporated as colloidal drug delivery system into lactose carrier particles using a spray drying technique. METHODS: The mixed micelles of TPGS5K and TPGS1K in different molar ratios (10:0, 7:3, 5:5, 3:7, 0:10) were prepared and physicochemical properties including: particle size, zeta potential, critical micelle concentration (CMC), drug loading, drug release rate, and in vitro cytotoxicitywere investigated in details. The optimized nanoparticles were co-spray dried with lactose carriers to produce the spherical particle morphology of the inhalable particles. RESULTS: Particle sizes and zeta potentials of the different formulations varied in the range of 102 to 196 nm and -9.4 to -13.8 mV, respectively. The lowest CMC values were calculated for 5:5 and 7:3 combinations (16.33 and 17.89 µM, respectively). The drug release rate from different formulations were very slow and only 30% of the drug was released during 72 h. Cytotoxicity assay demonstrated increased cytotoxic activity of PTX-loaded mixed micelles compared to the free drug. The in vitro deposition data indicated that spray drying of PTX-loaded micelles with lactose resulted in the production of inhalable powders with the high fine particle fraction (60%). CONCLUSION: These results demonstrate that this novel PTX-loaded micelles embedded in dry powder inhalation aerosol platform has a great potential to be used in lung cancer treatment.

Targeted Nanostructured Lipid Carrier for Brain Delivery of Artemisinin: Design, Preparation, Characterization, Optimization and Cell Toxicity.

In the present study, a transferrin-conjugated nanostructured lipid carrier (TF-NLCs) for brain delivery of artemisinin (ART) was developed. ART-loaded NLCs (ART-NLCs) were prepared using solvent evaporation method and the impact of various formulation or process variables on the responses were assessed using a Taguchi design. Optimized ART-NLC was then coupled with transferrin as targeting ligand and its in vitro cytotoxicity was investigated against U-87MG brain cancer cell line. As a result, the following values are suggested by the software to prepare the optimized formulation: 20 mg Compritol®, 0.25% Tween 80, 5 mg oleic acid, 2.5 mL dichloromethane and 4 min sonication. Mean particle size (PS), zeta potential (ZP), polydispersity index (PDI), entrapment efficiency (EE), mean release time (MRT) of adopted formulation were confirmed to be 145 ± 12.5 nm, 24.3 ± 1.5 mV, 0.513 ± 0.021, 82.3 ± 7.3 % and 24.0 ± 1.1 h, respectively. Following conjugation of optimized ART-NLCs with TF, PS and MRT were increased, while ZP, and EE were decreased significantly. TF-ART-NLCs showed higher cytotoxic activity compared to non-targeted NLCs and free drug. These results indicated that the TF-ART-NLCs could potentially be exploited as a delivery system for anticancer and antimalarial drug ART in brain tumors and malaria.

Preparation and characterization of an injectable thermosensitive hydrogel for simultaneous delivery of paclitaxel and doxorubicin.

In the current study, we aimed to develop a novel injectable thermosensitive hydrogel for simultaneous intra-tumoral administration of paclitaxel (PTX) and doxorubicin hydrochloride (DOX). At first, mixed micelles composed of Pluronic F127 and α-tocopheryl polyethylene glycol 1000 succinate (TPGS) was loaded with PTX and their physicochemical properties including particle size, zeta potential, drug loading content, entrapment efficiency, and the drug release were investigated in details. In the second step, the optimized PTX-loaded micelles prepared in the first step were incorporated into the thermosensitive Pluronic F127/hyaluronic acid (PF127/HA) hydrogel containing fixed amount of DOX. Gel formation temperature, rheological properties, injectability, degradation rates of the hydrogel, and the release rate of PTX and DOX from the hydrogel were examined. The mean particle sizes and zeta potentials of the PTX-loaded micelles were 157.5 ± 20.1 nm and -9.6 ± 1.1 mV, respectively. The entrapment efficiency of the formulation was about 51%. The hydrogel containing PTX-loaded micelles and DOX existed as a solution with low viscosity at 4 °C converted to a semisolid upon increasing the temperature to 35 °C. DOX was completely released from the hydrogel within 12 h, while 40-80% of PTX could be released from the different formulations during 3 days. This novel thermosensitive hydrogel prepared in the current study could be efficiently used for co-delivery of PTX and DOX in solid tumor types.

A novel mixed polymeric micelle for co-delivery of paclitaxel and retinoic acid and overcoming multidrug resistance: synthesis, characterization, cytotoxicity, and pharmacokinetic evaluation.

In the current study, retinoic acid (RA) was conjugated to Pluronic F127 (PF127) through an esterification process. Mixed micelles were formed with tocopheryl polyethylene glycol 1000 (TPGS) for co-delivery of paclitaxel (PTX) and RA to the cancer cells. Mixed micelles of RA-PF127 and TPGS in different weight ratios (10:0, 7:3, 5:5, 3:7, 0:10 w/w) were prepared and physicochemical properties including, particle size, zeta potential, critical micelle concentration (CMC), drug loading content, entrapment efficiency, drug release, cellular uptake and in vitro cytotoxicity, were investigated in details. Furthermore, the pharmacokinetics of PTX-loaded optimized mixed micelles were evaluated in Sprague-Dawley rats and compared with Stragen® (PTX in Cremophor EL®). Particle sizes and zeta potentials of the drug-loaded micelles were in the range of 102.6-223.5 nm and -5.3 to -9.6 mV, respectively. The 7:3 and 5:5 micellar combinations had lower CMC values (0.034-0.042 mg/mL) than 0:10 (0.124 mg/mL). The entrapment efficiencies of 10:0, 7:3, and 5:5 were 53.4 ± 9.3%, 61.3 ± 0.5%, and 78.7 ± 1.66%, respectively. The release rates of PTX from 7:3 and 5:5 mixed micelles were significantly slower than other formulations. Cytotoxicity assay demonstrated increased cytotoxic activity of PTX-loaded mixed micelles compared to free PTX. The Vd and t1/2ß of PTX-loaded RA-PF127/TPGS (7:3) were increased by 2.61- and 1.27-fold, respectively, while the plasma area under the curve (AUC) of the micelles was 2.03-fold lower than those of Stragen®. Therefore, these novel mixed micelles could be effectively used for delivery of PTX and RA to the cancer cells. Moreover, TPGS as part of micelle composition could enhance the therapeutic effect of PTX and reduce side effects.

PLGA-PEG-RA-based polymeric micelles for tumor targeted delivery of irinotecan.

To develop an effective therapeutic treatment, the potential of poly (lactic-co-glycolic acid)-polyethylene glycol-retinoic acid (PLGA-PEG-RA) polymeric micelles for targeted delivery of irinotecan to hepatocellular carcinoma (HepG2) and colorectal cancer cell lines (HT-29) was evaluated. PLGA-PEG-RA was synthesized by amide reaction of PLGA with NH2-PEG-NH2 and then PLGA-PEG-NH2 with RA and confirmed by FTIR and 1H NMR spectroscopy. Irinotecan-loaded nanomicelles were prepared using thin-film hydration method and the impact of various formulation variables on their particle size (PS), polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (EE), and mean release time (MRT) were assessed using a Taguchi design. TEM was used to observe morphology of the nanomicelles and the CMC was determined by fluorescence spectroscopy. Adopted PLGA-PEG-RA nanomicelle exhibited PS of 160 ± 9.13 nm, PDI of 0.20 ± 0.05, ZP of -24.9 ± 4.03 mV, EE of 83.9 ± 3.61%, MRT of 3.28 ± 0.35 h, and CMC value of 25.7 µg/mL. Cytotoxicity of the targeted nanomicelles on HepG2 and HT-29 cell lines was significantly higher than that of non-targeted nanomicelles and the free drug. These results suggest that PLGA-PEG-RA nanomicelles could be an efficient delivery system of irinotecan for targeted therapy of colorectal cancer and hepatocellular carcinoma.

Targeted Nanostructured Lipid Carriers for Delivery of Paclitaxel to Cancer Cells: Preparation, Characterization, and Cell Toxicity.

OBJECTIVE: Low water solubility, high systemic toxicity and insignificant cellular uptake have limited efficient clinical applications of the anti-tumor agent Paclitaxel (PTX). To overcome these limitations, a Novel Nanostructured Lipid Carrier (NLC) modified with Folic Acid (FA) and polyethylene glycol (PEG) was prepared by emulsion solvent evaporation method using cholesterol, α-tocopherol, lecithin and Poloxamer. A partial factorial design was applied to determine the appropriate levels of variables for optimized formulation. Formulations were evaluated for Particle Size (PS), Zeta Potential (ZP), Entrapment Efficiency (EE), and release efficiency (RE72%). FA- and PEGconjugated octadecylamine (FA-ODA and PEG-ODA) were synthesized and confirmed by FTIR and H-NMR and incorporated either alone or in combination with the optimized formulation whose properties were also evaluated. PTX-loaded optimized, targeted, pegylated, targeted/pegylated NLCs, pure PTX, and Anzatax® along with their respective controls were selected for toxicity evaluation on human breast cancer cell line, MCF-7, using MTT assay. METHODS: PS, ZP, EE%, and RE72% of the optimized formulation were 154.6 nm, -16.5 mv, 79.1% and 49.3%, respectively. Incorporation of α-tocopherol as the liquid lipid allowed for more efficient drug encapsulation, PS reduction, enhanced stability and sustained-release of the drug. Cytotoxicity of PTX-loaded NLCs modified with both FA-ODA and PEG-ODA was significantly enhanced compared to that of free PTX and other drug-loaded modified NLCs. RESULTS AND CONCLUSION: The results suggest that preparation of NLCs with synthesized conjugates might be a promising candidate for drug delivery of PTX to the cancerous cells and has a great potential as a carrier for tumor targeting in breast cancer.

Development and optimization of transferrin-conjugated nanostructured lipid carriers for brain delivery of paclitaxel using Box-Behnken design.

The treatment of brain cancer remains one of the most difficult challenges in oncology. The purpose of this study was to develop transferrin-conjugated nanostructured lipid carriers (Tf-NLCs) for brain delivery of paclitaxel (PTX). PTX-loaded NLCs (PTX-NLCs) were prepared using solvent evaporation method and the impact of various formulation variables were assessed using Box-Behnken design. Optimized PTX-NLC was coupled with transferrin as targeting ligand and in vitro cytotoxicity of it was investigated against U-87 brain cancer cell line. As a result, 14.1 mg of cholesterol, 18.5 mg of triolein, and 0.5% poloxamer were used to prepare the optimal formulation. Mean particle size (PS), zeta potential (ZP), entrapment efficiency (EE), drug loading (DL), mean release time (MRT) of adopted formulation were confirmed to be 205.4 ± 11 nm, 25.7 ± 6.22 mV, 91.8 ± 0.5%, 5.38 ± 0.03% and 29.3 h, respectively. Following conjugation of optimized PTX-NLCs with transferrin, coupling efficiency was 21.3 mg transferrin per mmol of stearylamine; PS and MRT were increased while ZP, EE and DL decreased non-significantly. Tf-PTX-NLCs showed higher cytotoxic activity compared to non-targeted NLCs and free drug. These results indicated that the Tf-PTX-NLCs could potentially be exploited as a delivery system in brain cancer cells.

A simple and sensitive high-performance liquid chromatography method for determination of ciprofloxacin in bioavailability studies of conventional and gastroretentive prolonged-release formulations.

BACKGROUND: A very simple, sensitive, and accurate high-performance liquid chromatography (HPLC) method with ultraviolet detector was developed and applied to determine ciprofloxacin in human plasma following administration of a gastroretentive formulation developed in our laboratory. MATERIALS AND METHODS: HPLC analysis was performed on a C18 µ-Bondapack column (250 mm × 3.9 mm) using acetonitrile: potassium dihydrogen phosphate solution 0.1 M (20:80, v/v, pH 3) at a flow rate of 1.5 ml/min and eluate was monitored at 276 nm. After addition of phenacetin as internal standard, plasma samples were treated with 0.1 M phosphate buffer (pH: 7) and followed by extraction with dichloromethane. The method was validated for linearity, precision, accuracy, limit of quantitation (LOQ), robustness, stability, and applied in bioavailability studies of our developed gastroretentive formulation in healthy volunteers. RESULTS: The calibration curves were linear over the concentration range 0.025-4 µg/ml with the detection limit of 15 ng/ml. Accuracy % were within 93-115 and the coefficient of variance % ranged from 0.20 to 12.8. The very low LOQ (25 ng/ml) allowed avoiding fluorometric detection which is more expensive and is not available in all laboratories. Ciprofloxacin was stable in samples with no evidence of degradation during 3 freeze-thaw cycles and 3 months storage at -70°C. CONCLUSION: This validated HPLC method was successfully used for the determination of ciprofloxacin in human plasma following oral administration of controlled release formulation, conventional immediate-release tablets and when administered concomitantly with divalent and trivalent cations such as aluminum-, magnesium-, or calcium-containing products under which the bioavailability of ciprofloxacin is significantly reduced.