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.

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.

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.

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.

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 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.

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.

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 Rapid and Sensitive HPLC Method for Quantitation of Paclitaxel in Biological Samples using Liquid-Liquid Extraction and UV Detection: Application to Pharmacokinetics and Tissues Distribution Study of Paclitaxel Loaded Targeted Polymeric Micelles in Tumor Bearing Mice.

A simple, rapid, and sensitive reversed-phase HPLC method was developed and validated for determination of paclitaxel (PTX) in plasma, various organs and tumor tissues of tumor-bearing mice. Tissue specimens of liver, kidneys, spleen, lungs, heart and tumor were separately homogenized in normal saline. Plasma or tissue homogenate (250 µl) containing PTX and internal standard (diazepam) were extracted by diethyl ether (6 ml). The separation was achieved on a µ-Bondapak C18 HPLC column using sodium acetate buffer solution (0.01 M)/acetonitrile (58/42 v/v) at pH 5 ± 0.1 and flow rate of 1.9 mL/min. The effluent was monitored at 227 nm and column temperature was adjusted at 58ºC. The internal standard and PTX were eluted at 4.2 and 5.2 min, respectively and no interfering peaks were observed. Calibration curves were linear over the concentration range of 0.25-10 µg/ml of PTX in plasma and 0.3-20 µg/ml PTX in tissue homogenates with acceptable precision and accuracy (<15%). The mean recoveries of the drug after plasma extraction was 87.4% ± 3.6 while those of tissue homogenates ranged from 62.1± 4.5 to 75.5± 3.2 depending on the type of tissues studied. PTX was stable in samples with no evidence of degradation during 3 freeze-thaw cycles and 3 months storage at -70 °C. The developed HPLC method was applied to quantify PTX in the mouse plasma and tissues after intravenous administration of 10 mg equivalent PTX/Kg dose of PTX-loaded tocopherol succinate-chitosan-polyethylene glycol-folate (TS-CS-PEG-FA) micelles formulation or Anzatax® (Cremophor® EL- based formulation of PTX) to female Balb/c mice.

Co-delivery of paclitaxel and α-tocopherol succinate by novel chitosan-based polymeric micelles for improving micellar stability and efficacious combination therapy.

The aim of this study was to develop chitosan derivative polymeric micelles for co-delivery of paclitaxel (PTX) and α-tocopherol succinate (α-TS) to the cancer cells to improve the therapeutic efficiency and reduce side effects of PTX. In this study, amphiphilic tocopheryl succinate-grafted chitosan oligosaccharide was synthesized and physically loaded by PTX and α-TS with entrapment efficiency of 67.9% and 73.2%, respectively. Physical incorporation of α-TS into the micelles increased the hydrophobic interaction between PTX and the micelles core, which improved micelle stability, reduced the micelle size and also sustained the PTX release from the micelles. The mean particle size and zeta potential of αTS/PTX-loaded micelles were about 133 nm and +25.2 mV, respectively, and PTX release was completed during 6-9 d from the micelles. Furthermore, the cytotoxicity of α-TS/PTX-loaded micelles against human ovarian cancer cell line cancer cell in vitro was higher than that of PTX-loaded micelles and the free drug solution. Half maximal inhibitory concentration values of PTX after 48-h exposure of the cells to the PTX-loaded micelles modified and unmodified with α-TS were 110 and 188 ng/ml, respectively.

Formulation and optimization of celecoxib-loaded PLGA nanoparticles by the Taguchi design and their in vitro cytotoxicity for lung cancer therapy.

The objective of the present study was to develop, evaluate and optimize a polymeric nanoparticle (NP) system containing Cxb for pulmonary delivery of Cxb in the treatment of lung cancer. NPs were prepared by the emulsion solvent diffusion and evaporation method using poly(D, L lactideglycolide) (PLGA). The size of NPs ranged from 153 to 192 nm and was affected by PLGA content, surfactant concentration and organic phase volume. Zeta potential of NPs (-4.5 to -8.6 mV) was more affected by PLGA content and organic phase volume. PLGA content was also the most effective factor on the entrapment efficiency and release rate of Cxb from NPs. The optimum formulation which obtained with 5 mg Cxb, 25 mg PLGA, 0.5% surfactant, 2.5% organic volume and 15 000 rpm showed release of Cxb within 30 h. The optimized formulation co-spray dried with lactose (hybrid microparticles) displayed desirable fine particle fraction, mass medium aerodynamic diameter, geometric standard deviation of 70.3%, 1.46% and 3.38%, respectively. Our results provide evidence for the potential of PLGA NPs for delivery of Cxb through inhalation as means to alleviate the cardiovascular risk of Cxb administration.

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.

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.

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.

Microencapsulation of budesonide with dextran by spray drying technique for colon-targeted delivery: an in vitro/in vivo evaluation in induced colitis in rat.

The aim of this study was developing colon targeted-delivery of budesonide for ulcerative colitis. Microcapsules were prepared using spray drying technique by different drug-to-dextran ratios and three molecular weights (MWs) of polymer. Differential scanning calorimetry, X-ray diffraction (XRD), drug release and loading efficiency of microcapsules were studied. In vivo efficacy of the selected formulation prepared by 1 : 10 drug-to-polymer ratio and dextran with MW 500 000 (D10M500) against acetic acid-induced colitis in rats was evaluated and compared to the control and reference groups (mesalasine and budesonide suspensions). The results showed that D10M500 microcapsules could target the drug to colon and its efficacy in reducing macroscopic damage score was higher than mesalasine suspension. Treatment with D10M500 decreased the scores of crypt damage and total colitis significantly compared to the control group which just received the vehicle and the groups treated with mesalasine and budesonide suspension which could not reduce the colitis parameters significantly.

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.

Effectiveness of budesonide-succinate-dextran conjugate as a novel prodrug of budesonide against acetic acid-induced colitis in rats.

BACKGROUND: Anti-inflammatory drugs with high potency and low systemic adverse effects, such as budesonide, are drugs of choice for the treatment of ulcerative colitis (UC). Budesonide controlled-release formulations are now being used to induce and maintain clinical remission of Crohn's disease. Budesonide-dextran conjugates were synthesized as novel prodrugs of budesonide for oral controlled delivery of the major part of the drug to the colon without needing to coat the pellets of the drug. The aim of this study was to evaluate the in vivo efficacy of this conjugate against acetic acid-induced colitis in rats. MATERIALS AND METHODS: Experimental UC was induced by rectal instillation of 4% solution of acetic acid to rats. After induction of colitis, rats were treated with vehicle (dextran solution), mesalasine (120 mg/kg), budesonide suspension (300 microg/kg) and BSD-70 (equivalent to 300 microg/kg of budesonide), prednisolon (4 mg/kg), hydrocortisone acetate enema (20 mg/kg), and 5-ASA enema (Asacol) (400 mg/kg) for 5 days and then colon macroscopic and microscopic sections were examined for inflammatory response. RESULTS: Vehicle-treated rats presented bloody diarrhoea and gross lesions. The effective formulations for attenuating the damage were BSD-70, oral prednisolon and hydrocortisone acetate enema. Rats treated with BSD-70 showed huge improvement in macroscopic and histological scores of colitis compared to the negative control group and mesalasine and budesonide suspension. CONCLUSION: Data indicated that budesonide-dextran conjugate is effective in improving signs of inflammation in experimental model of colitis through selective delivery of the drug to the inflamed area.

Pharmacokinetics and pharmacodynamics of controlled release insulin loaded PLGA microcapsules using dry powder inhaler in diabetic rats.

The pulmonary route is an alternative route of administration for the systemic delivery of peptide and proteins with short-half lives. A long-acting formulation of insulin was prepared by encapsulation of protein into respirable, biodegradable microcapsules prepared by an oil in oil emulsification/solvent evaporation method. Insulin-loaded PLGA microcapsules prepared as a dry powder inhaler formulation were administered via the pulmonary route to diabetic rats and serum insulin and glucose concentrations were monitored. Control treatments consisted of respirable spray-dried insulin (RSDI) powder administered by intratracheal insufflation, insulin-loaded PLGA microcapsules and NPH (long-acting) insulin administered by subcutaneous (SC) administration. Pharmacokinetic analysis demonstrated that insulin administered in PLGA microcapsules illustrated a sustained release profile which resulted in a longer mean residence time, 4 and 5 fold longer than those after pulmonary administration of RSDI and SC injection of NPH insulin, respectively. Accordingly, the hypoglycemic profile followed a stable and sustained pattern which remained constant between 10 and 48 h. Results of the in vitro experiments were in good agreement with those of in vivo studies. Bronchoalveolar lavage fluid analysis indicated that microcapsules administration did not increase the activities of lactate dehydrogenase and total protein. However, histological examination of the lung tissue indicated a minor but detectable effect on the normal physiology of the rat lung. These findings suggest that the encapsulation of peptides and proteins into PLGA microcapsules technique could be a promising controlled delivery system for pulmonary administration.

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.