Preparation, characterization and pharmacokinetic studies of tacrolimus-dimethyl-β-cyclodextrin inclusion complex-loaded albumin nanoparticles

The purpose of the study is to develop a new formulation for clinically used anti-cancer agent tacrolimus (FK506) to minimize the severe side effects. Toward this end, a new formulation method has been developed by complexation of FK506 with an hydrophilic cyclodextrin derivative, heptakis (2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD) using ultrasonic means. The resulting complex displays dramatically enhanced solubility of FK506. Then bovine serum albumin (BSA) nanoparticles were prepared directly from the preformed FK506/DM-β-CD inclusion complex by the desolvation-chemical crosslinking method, with the size of 148.4-262.9 nm. Stable colloidal dispersions of the nanoparticles were formed with zeta potentials of the range of -24.9 to -38.4 mV. The entrapment efficiency of FK506 was increased as high as 1.57-fold. Moreover, notably FK506 was released from the nanoparticles in a sustained manner. As demonstrated, pharmacokinetic studies reveal that, as compared with FK506-loaded BSA nanoparticles, the FK506/DM-β-CD inclusion complex-loaded BSA nanoparticles have significant increase at T(max), t(1/2), MRT and decrease at C(max). In summary, these results suggest that the drug/DM-β-CD inclusion complex-loaded BSA nanoparticles display significantly improved delivery efficiency for poorly soluble FK506 or its derivatives.     

Preparation,characterization, dissolution,and permeation of flibanserin − 2-HP-β-cyclodextrin inclusion complexes

Flibanserin (FLB), an antiserotonin drug, is used to treat women with hypoactive sexual appetite disorder. FLB shows low bioavailability (~33%) probably due to its low water solubility. The current study investigated the impact of hydroxypropyl-β-cyclodextrin (HP-β-CD) and sodium lauryl sulfate (SLS) on the dissolution and permeation of FLB. HP-β-CD–FLB inclusion complexes were prepared using physical mixing and kneading at 1:1 and 1:2 M ratios and characterized using differential scanning calorimetry, Fourier transform infrared spectroscopy, and powder X-ray diffractometry. The dissolution and permeation of the complexes through a cellophane membrane were performed in, 0.1, 0.3 and 0.5% SLS in phosphate buffer (pH 6.8).Derived from the slope of the linear phase solubility diagram, the apparent stability constant (K_1:1) was 372.54 M⁻¹. Kneading changed the crystalline form of FLB to an amorphous appearance characterized by minimal crystalline peaks, indicating successful inclusion complex formation. In addition, the HP-β-CD–FLB inclusion complexes showed twofold increased dissolution efficiency at 6 h. The cumulative FLB amount permeated at 6 h increased from 14.1% to 21.88% and 34.56% in the presence of 0.1% and 0.3% of SLS, respectively. However, increasing SLS to 0.5% did not show an increase in FLB permeation. Therefore, the HP-β-CD–FLB inclusion complex has an improved dissolution rate compared to FLB alone. The presence of SLS in the dissolution medium increases the dissolution rate of pure FLB and its complex with HP-β-CD. kneaded 1:1 complex was formulated bioadhesive buccal tablets and showed enhanced drug release.     

Preparation and characterization of interferon-γ-containing liposomes

An immunoenzymatic (ELISA) assay was used to quantify the amount of interferon-γ, (IFN-γ) entrapped in liposomes extruded through polycarbonate membranes of 0.2 μm pore size. Tween 20 (1% final concentration) was able to disrupt the vesicles and release the entrapped material without affecting IFN-γ, activity, whereas a significant loss of activity was observed with Triton X-100 or Nonidet P-40. A substantial portion of the protein was adsorbed to glass and plastic surfaces during the preparation of IFN-y-containing liposomes, resulting in relatively low trapping efficiencies. Saturation of the material with a blocking buffer and/or adjunction of bulk proteins (murine albumin and gelatin) to the liposomal preparation increased only slightly the amount of encapsulated IFN-γ. However, incorporation of IFN-γ, within preformed blank liposomes using a freeze-thawing method yielded much better results, since up to 30% of the starting material was entrapped in the vesicles when the procedure was carried out in polystyrene tubes treated with polyether-polydimethyl-siloxane (PDMS).     

Preparation and characterization of D,L-PLA loaded 17-β-Estradiol valerate by emulsion/evaporation methods

PLA microparticles containing 17-β-estradiol valerate were prepared by an emulsion/evaporation method in order to sustain drug release. This system was characterized concerning particle size, particle morphology and the influence of formulation and processing parameters on drug encapsulation and in vitro drug release. The biodegradation of the microparticles was observed by tissue histological analysis. Scanning electron microscopy and particle size analysis showed that the microparticles were spherical, presenting non-aggregated homogeneous surface and had diameters in the range of 718–880 nm (inert micro-particles) and 3–4 µm (drug loaded microparticles). The encapsulation efficiency was ～80%. Hormone released from microparticles was sustained. An in vivo degradation experiment confirmed that microparticles are biodegradable. The preparation method was shown to be suitable, since the morphological characteristics and efficiency yield were satisfactory. Thus, the method of developed microparticles seems to be a promising system for sustained release of 17-β-estradiol.     

Preparation,purification and characterization of the polyclonal antibody against α1-AT

Objective To prepare the polyclonal antibody against α1-antitrypsin(α1-AT)by immunizing rabbits with α1-AT,and to purify and characterize the antibodies produced from rabbits in order to establish the production process of the polyclonal antibody against α1-AT.Methods The healthy rabbits were routinely immunized with α1-AT to prepare polyclonal antibody against α1-AT.The serum antibody titers were determined by ELISA.The rabbits with qualified antibody titers were killed to collect blood.The antisera,obtained by centrifugalizing the whole blood,were purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography.The purified polyclonai antibodies were analyzed by 15%SDS-PAGE,and antibody titers weIe measured by ELISA.Results ELISA assay showed that the titers of antisera were over 105.The polyclonal antibodies,purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography,had good purity and immunological activity.Conclusion The production and purification processes of polyclonal antibody against α1-AT are successfully established.     

Preparation,purification and characterization of the polyclonal antibody against α1-AT

Objective To prepare the polyclonal antibody against α1-antitrypsin(α1-AT)by immunizing rabbits with α1-AT,and to purify and characterize the antibodies produced from rabbits in order to establish the production process of the polyclonal antibody against α1-AT.Methods The healthy rabbits were routinely immunized with α1-AT to prepare polyclonal antibody against α1-AT.The serum antibody titers were determined by ELISA.The rabbits with qualified antibody titers were killed to collect blood.The antisera,obtained by centrifugalizing the whole blood,were purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography.The purified polyclonai antibodies were analyzed by 15%SDS-PAGE,and antibody titers weIe measured by ELISA.Results ELISA assay showed that the titers of antisera were over 105.The polyclonal antibodies,purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography,had good purity and immunological activity.Conclusion The production and purification processes of polyclonal antibody against α1-AT are successfully established.     

Preparation,purification and characterization of the polyclonal antibody against α1-AT

Objective To prepare the polyclonal antibody against α1-antitrypsin(α1-AT)by immunizing rabbits with α1-AT,and to purify and characterize the antibodies produced from rabbits in order to establish the production process of the polyclonal antibody against α1-AT.Methods The healthy rabbits were routinely immunized with α1-AT to prepare polyclonal antibody against α1-AT.The serum antibody titers were determined by ELISA.The rabbits with qualified antibody titers were killed to collect blood.The antisera,obtained by centrifugalizing the whole blood,were purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography.The purified polyclonai antibodies were analyzed by 15%SDS-PAGE,and antibody titers weIe measured by ELISA.Results ELISA assay showed that the titers of antisera were over 105.The polyclonal antibodies,purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography,had good purity and immunological activity.Conclusion The production and purification processes of polyclonal antibody against α1-AT are successfully established.     

Preparation and characterization of D, L-PLA loaded 17-β-Estradiol valerate by emulsion/evaporation methods

PLA microparticles containing 17-β-estradiol valerate were prepared by an emulsion/evaporation method in order to sustain drug release. This system was characterized concerning particle size, particle morphology and the influence of formulation and processing parameters on drug encapsulation and in vitro drug release. The biodegradation of the microparticles was observed by tissue histological analysis. Scanning electron microscopy and particle size analysis showed that the microparticles were spherical, presenting non-aggregated homogeneous surface and had diameters in the range of 718-880 nm (inert micro-particles) and 3-4 μm (drug loaded microparticles). The encapsulation efficiency was ～80%. Hormone released from microparticles was sustained. An in vivo degradation experiment confirmed that microparticles are biodegradable. The preparation method was shown to be suitable, since the morphological characteristics and efficiency yield were satisfactory. Thus, the method of developed microparticles seems to be a promising system for sustained release of 17-β-estradiol.     

Preparation of meloxicam-β-cyclodextrin-polyethylene glycol 6000 ternary system: characterization, in vitro and in vivo bioavailability

Ternary complexes of meloxicam (ML), a poorly water-soluble anti-inflammatory drug, with β-cyclodextrin (βCD) and polyethylene glycol (PEG) 6000 were prepared from an equimolar (ML-βCD) and 10% of PEG. Characterization of the ternary complex was carried out by differential scanning calorimetry and X-ray diffractometry. The solubility of ML increased as a function of increasing the concentration of βCD and PEG 6000. Ternary system increased significantly ML solubility in water. Ternary complexes improved drug release compared with ML and ML-βCD. The oral bioavailability of ML-βCD-PEG was investigated by administration to rat and compared with ML and ML-βCD. The results confirmed that the oral bioavailability of ML was significantly improved by complexation with βCD in the presence of PEG.     

Preparation,purification and characterization of the polyclonal antibody against α1-AT

Objective To prepare the polyclonal antibody against α1-antitrypsin(α1-AT)by immunizing rabbits with α1-AT,and to purify and characterize the antibodies produced from rabbits in order to establish the production process of the polyclonal antibody against α1-AT.Methods The healthy rabbits were routinely immunized with α1-AT to prepare polyclonal antibody against α1-AT.The serum antibody titers were determined by ELISA.The rabbits with qualified antibody titers were killed to collect blood.The antisera,obtained by centrifugalizing the whole blood,were purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography.The purified polyclonai antibodies were analyzed by 15%SDS-PAGE,and antibody titers weIe measured by ELISA.Results ELISA assay showed that the titers of antisera were over 105.The polyclonal antibodies,purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography,had good purity and immunological activity.Conclusion The production and purification processes of polyclonal antibody against α1-AT are successfully established.     

Preparation,purification and characterization of the polyclonal antibody against α1-AT

Objective To prepare the polyclonal antibody against α1-antitrypsin(α1-AT)by immunizing rabbits with α1-AT,and to purify and characterize the antibodies produced from rabbits in order to establish the production process of the polyclonal antibody against α1-AT.Methods The healthy rabbits were routinely immunized with α1-AT to prepare polyclonal antibody against α1-AT.The serum antibody titers were determined by ELISA.The rabbits with qualified antibody titers were killed to collect blood.The antisera,obtained by centrifugalizing the whole blood,were purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography.The purified polyclonai antibodies were analyzed by 15%SDS-PAGE,and antibody titers weIe measured by ELISA.Results ELISA assay showed that the titers of antisera were over 105.The polyclonal antibodies,purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography,had good purity and immunological activity.Conclusion The production and purification processes of polyclonal antibody against α1-AT are successfully established.     

Preparation,purification and characterization of the polyclonal antibody against α1-AT

Objective To prepare the polyclonal antibody against α1-antitrypsin(α1-AT)by immunizing rabbits with α1-AT,and to purify and characterize the antibodies produced from rabbits in order to establish the production process of the polyclonal antibody against α1-AT.Methods The healthy rabbits were routinely immunized with α1-AT to prepare polyclonal antibody against α1-AT.The serum antibody titers were determined by ELISA.The rabbits with qualified antibody titers were killed to collect blood.The antisera,obtained by centrifugalizing the whole blood,were purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography.The purified polyclonai antibodies were analyzed by 15%SDS-PAGE,and antibody titers weIe measured by ELISA.Results ELISA assay showed that the titers of antisera were over 105.The polyclonal antibodies,purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography,had good purity and immunological activity.Conclusion The production and purification processes of polyclonal antibody against α1-AT are successfully established.     

Preparation,purification and characterization of the polyclonal antibody against α1-AT

Objective To prepare the polyclonal antibody against α1-antitrypsin(α1-AT)by immunizing rabbits with α1-AT,and to purify and characterize the antibodies produced from rabbits in order to establish the production process of the polyclonal antibody against α1-AT.Methods The healthy rabbits were routinely immunized with α1-AT to prepare polyclonal antibody against α1-AT.The serum antibody titers were determined by ELISA.The rabbits with qualified antibody titers were killed to collect blood.The antisera,obtained by centrifugalizing the whole blood,were purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography.The purified polyclonai antibodies were analyzed by 15%SDS-PAGE,and antibody titers weIe measured by ELISA.Results ELISA assay showed that the titers of antisera were over 105.The polyclonal antibodies,purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography,had good purity and immunological activity.Conclusion The production and purification processes of polyclonal antibody against α1-AT are successfully established.     

Preparation,purification and characterization of the polyclonal antibody against α1-AT

Objective To prepare the polyclonal antibody against α1-antitrypsin(α1-AT)by immunizing rabbits with α1-AT,and to purify and characterize the antibodies produced from rabbits in order to establish the production process of the polyclonal antibody against α1-AT.Methods The healthy rabbits were routinely immunized with α1-AT to prepare polyclonal antibody against α1-AT.The serum antibody titers were determined by ELISA.The rabbits with qualified antibody titers were killed to collect blood.The antisera,obtained by centrifugalizing the whole blood,were purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography.The purified polyclonai antibodies were analyzed by 15%SDS-PAGE,and antibody titers weIe measured by ELISA.Results ELISA assay showed that the titers of antisera were over 105.The polyclonal antibodies,purified by caprylic acid-ammonium sulfate precipitation and protein A affinity chromatography,had good purity and immunological activity.Conclusion The production and purification processes of polyclonal antibody against α1-AT are successfully established.     

Preparation,characterization, and sonodynamic antitumor effect of the folate receptor targeted FA-EN-β-CD containing hematoporphyrin in vitro

To improve water solubility, reduce phototoxicity and increase the tumor-targeting ability of hematoporphyrin (Hp) as a sonosensitizer for sonodynamic therapy under ultrasonic conditions, a novel folate receptor (FR)-targeted, folate-conjugated ethylenediamine-β-cyclodextrin (FA-EN-β-CD) containing Hp (FA-EN-β-CD-Hp) was constructed. β-Cyclodextrin containing Hp (β-CD-Hp) was also established as a nontargeted control. The inclusion efficiencies of Hp in FA-EN-β-CD-Hp and β-CD-Hp were determined to be 90.4 ± 2.7% (wt/wt) and 92.5 ± 3.4% (wt/wt), respectively. Growth inhibition rates in HepG-2 cells in vitro were assessed upon ultrasound exposure. The results indicated that the growth inhibition rates of FA-EN-β-CD-Hp, β-CD-Hp, and F-Hp (Hp: 150 μg/ml) reached 96.4 ± 3.6%, 53.4 ± 3.4%, and 48.2 ± 2.8%, respectively. These results indicated that FA-EN-β-CD-Hp is a promising drug delivery system in the field of sonodynamic cancer therapy.     

β-cyclodextrin complexes of celecoxib: Molecular-modeling, characterization, and dissolution studies

Celecoxib, a specific inhibitor of cycloxygenase-2 (COX-2) is a poorly water-soluble nonsteroidal anti-inflammatory drug with relatively low bioavailability. The effect of beta-cyclodextrin on the aqueous solubility and dissolution rate of celecoxib was investigated. The possibility of molecular arrangement of inclusion complexes of celecoxib and beta-cyclodextrin were studied using molecular modeling and structural designing. The results offer a better correlation in terms of orientation of celecoxib inside the cyclodextrin cavity. Phase-solubility profile indicated that the solubility of celecoxib was significantly increased in the presence of beta-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Solid complexes prepared by freeze drying, evaporation, and kneading methods were characterized using differential scanning calorimetry, powder x-ray diffractometry, and scanning electron microscopy. In vitro studies showed that the solubility and dissolution rate of celecoxib were significantly improved by complexation with beta-cyclodextrin with respect to the drug alone. In contrast, freeze-dried complexes showed higher dissolution rate than the other complexes.     

Preparation, characterization, and screening of a high affinity organometallic probe for α-adrenergic receptors

An organometallic rhenium complex having high and selective affinity for α-adrenergic receptors is reported. A series of methoxyphenylpiperazinecarborane ligands complexed to the [Re(CO)(3)](+) core were prepared and the resulting organometallic compounds screened for binding to serotonin, σ, and adrenergic receptors as well as dopamine, serotonin, and norepinephrine transporters. An amide linked derivative, for which a single crystal X-ray structure was obtained, showed high and selective affinity toward α(1A), α(1D), and α(2C) adrenergic receptors with K(i) values of 17, 21, and 39 nM, respectively. A method to prepare the corresponding (99m)Tc complex was also developed where the resulting metallocarborane was shown to be stable and is therefore suitable for in vivo molecular imaging studies.     

Preparation and characterization of β-cyclodextrin and poly(acrylic acid) microspheres

Abstract

A method for the preparation of poly(acrylic acid) (PAA) microspheres cross-linked with beta-cyclodextrin (β-CD) is described. The method is based on a water-in-oil (w/o) emulsion solvent evaporation technique which facilitates a condensation reaction between PAA and β-CD. Aqueous solutions of PAA and β-CD were used as the dispersed phase and food grade olive oil was used as the continuous phase. The effect of homogenization speed (used in the preparation of the emulsion), phase volume ratio and cyclodextrin-polymer load on the particle size of the microspheres produced was investigated in a replicated factorial design. Microspheres were sized by light microscopy. The particle size of the microspheres was influenced by all three variables with two significant first order interactions between the variables being observed (homogenization speed with phase volume ratio and homogenization speed with load). A second order interaction between the three principal factors was also observed. Particle size ranged from 16 to 150m, depending on the production variables employed. The yield for the technique was 69.5 × 9.5%. Using selected conditions, microspheres of 15–25 pm size were prepared from a range of PAA with different weight average molecular weights (w). These particles were then characterized for β-CD, free carboxylic acid group content and residual oleic acid.     

Preparation and evaluation of ketoconazole-β-cyclodextrin multicomponent complexes

Increase in poor buffer pH 5 and 6 solubility of ketoconazole was studied. Two systems were used: binary complexes prepared with β -cyclodextrin and multicomponent systems (β-cyclodextrin and an acid compound), obtained by spray-drying. X-ray diffractometry and differential scanning calorimetry showed differences between ketoconazole/cyclodextrin complexes and their corresponding physical mixtures and individual components. The solubility of ketoconazole increased significantly with the cyclodextrin complexes. However, enhancement was better from the multicomponent systems.     

Physcion and physcion 8-O-β-glucopyranoside:a review of their pharmacology,toxicities and pharmacokinetics

Anthraquinones constitute an important class of natural and synthetic compounds with a broad scope of pharmacological including anti-bacterial, antioxidant, laxative, anti-tumor and other activities. Physcion and physcion 8-O-β-glucopyranoside(PG) are common anthraquinones existed in various plants. Emerging studies suggested that physcion and PG not only exert antitumor, anti-microbial, anti-inflammatory, anti-oxidant, optical-related, enzyme inhibitory, lipid regulation and neuroprotective activities, but also lead to hepatotoxicity, renal toxicity and genetic damage. Besides, a growing number of pharmacokinetics researches of physcion and PG also have been conducted. However, no review of physcion or PG have been published by now, so the aim of present review is to give a comprehensive summary and analysis of the pharmacology, toxicity and pharmacokinetics of physcion and PG by consulting all the currently available literatures published in Pub Med then give a future prospects about it.