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1.
Griseofulvin is a commonly used antifungal agent which is administered per oral (p.o.). The oral administration route, however, shows rather low bioavailability. The aim of this study was to improve the bioavailability and to evaluate and interpret the pharmacokinetic profiles after subcutaneous (s.c.) administration of crystalline griseofulvin nano- and microsuspensions. Both formulations were injected at 5 and 500 µmol/kg to rats. For the lower concentration, the profiles were similar after s.c. injection but extended as compared to p.o. administration. For the higher concentration, injection of microsuspension resulted in a maintained plateau whereas the nanosuspension resulted in an obvious peak exposure followed by extended elimination. Both suspensions showed improved exposure with dose. The differences in peak exposures between nano- and microparticles, at the high dose, were mainly ascribed to differences in dissolution rate, experimentally determined in vitro, using spectroscopic methods. The extended appearance in the circulation may depend on the physicochemical properties of the compound and the physiological conditions at the injection site. The bioavailability was improved for both formulations compared with an orally administered nanosuspension, suggesting the s.c. route to be a preferred administration option for compounds with low oral bioavailability regarding both overall exposure and extended efficacy.  相似文献   

2.
In the present paper, BA99 and AC88 were used as model compounds for intraperitoneal (i.p.) administration to Sprague-Dawley rats. A major problem for the compounds, like many others newly developed pharmaceutical drugs, is the poor solubility in water. To solve solubility related problems, development of nanosuspensions is an attractive alternative. Both compounds are suitable for nanosuspensions, using the milling approach. After 2 weeks in freezer, the nanoparticles aggregated to form particles in the 400–2000?nm interval. However, following a 20 s ultrasonication step, the original particle sizes (about 200?nm) were obtained. Adding 5% mannitol before the samples were frozen abolished aggregation. It is also possible to freeze-dry the nanosuspension in the presence of 5% mannitol and re-disperse the formulation in water. Nanosuspensions of both compounds were injected i.p. to rats at 5 and 500 µmoL/kg. At the low dose, also a microsuspension was administered. I.p. administration resulted in overall improved Cmax for both AC88 and BA99 compared to s.c. and oral administration. I.p. is the preferred route of administration of tolerable drugs when a fast onset of action is desired and when a significant first passage metabolism occurs. The net charge of the active molecule appeared to affect the absorption kinetics. In the present work, the neutral molecule was favored over the negatively charged one.  相似文献   

3.
Background: In this study, nanosuspension was prepared to improve the dissolution rate and bioavailability of lipophilic fenofibrate. Method: Melt emulsification method combined with high-pressure homogenization was adapted, and mixture of poloxamer188 and PVP K30 were selected as surfactants. This method consumed less energy and was more efficient than traditional homogenization of drug solid particles suspension directly. Results: The dissolution rate of fenofibrate nanosuspension was increased obviously, and the product was evaluated by pharmacokinetic characteristic in rats. The AUC0–36 h and Cmax of nanosuspensions were increased when compared with the reference formulations. No significant differences were found between the two nanosuspensions A and B, of which the mean particle sizes were 356 and 194 nm, respectively. Therefore, nanosuspensions may be a suitable delivery system to improve the bioavailability of those drugs with poor water solubility.  相似文献   

4.
In Sigfridsson et al. (2011, Drug Dev Ind Pharm, 37:243-251), there was no difference in plasma concentration of BA99 when administering the drug as nanosuspension or microsuspension and analyzing the blood samples by liquid chromatography-mass spectrometry. This was related to the dissolved amount of drug in the gastric tract, which was high enough to support fast absorption when the drug reached the small intestine. One single physicochemical property (pK(a), about 3 for BA99) abolished the benefit of small particles. These results were further confirmed in the present study, where a proton pump inhibitor, AZD0865, was used to elevate the gastric pH and then drastically decreased the gastric solubility. In this way, BA99 could be considered as a model compound for a neutral substance. By increasing the gastric pH to 5-6 and 8-9, respectively, in rats, the plasma concentrations of BA99, after administering nanosuspensions, were unchanged compared with untreated (i.e. no AZD0865) animals. For microsuspensions of the test compound, on the other hand, the exposure of BA99 was 2- to 3-fold lower than for nanosuspensions at both pHs. Moreover, the blood concentrations of BA99 administered as microsuspension were also 2- to 3-fold lower compared with untreated (no AZD0865) individuals receiving both nanoparticles and microparticles of BA99. Obviously, for neutral compounds, with similar physicochemical properties as the present compound, size reduction will be crucial for increased plasma exposure. For basic compounds, with similar physicochemical properties as the present compound, the crucial step for absorption is the dissolution and solubility in the gastric tract.  相似文献   

5.
The purpose of this study was to investigate the formation of drug nanoparticles from binary and ternary mixtures, consisting of dihydroartemisinin (DHA), a poorly water-soluble antimalarial drug, with water-soluble polymer and/or surfactant. Binary mixtures of drug/polyvinyl pyrrolidone K30 (PVP K30), binary mixtures of drug/sodium deoxycholate (NaDC), and ternary mixtures of drug/PVP K30/NaDC were prepared at different weight ratios and then ground by vibrating rod mill to obtain ground mixtures. Nanosuspension was successfully formed after dispersing ternary ground mixtures or DHA/NaDC ground mixtures in water. The ternary ground mixtures did not give superior nanosuspension in terms of particle size reduction and recovery of drug nanoparticles, but they provided more physically stable nanosuspensions than DHA/NaDC ground mixtures. The size of drug nanoparticles was decreased with increasing grinding time and lowering amount of PVP K30 and NaDC. About 95% of drug nanoparticles were found in the nanosuspension from ternary ground mixtures. Zeta potential measurement suggested that stable nanosuspension was attributable to adsorption of NaDC and PVP K30 onto surface of drug particles. Atomic force microscopy and transmission electron microscopy with selected area diffraction indicated that DHA in nanosuspension was existed as nanocrystals. The obtained nanosuspensions had higher in vitro antimalarial acitivity against Plasmodium falciparum than microsuspensions. The results suggest that co-grinding of DHA with PVP K30 and NaDC seems to be a promising method to prepare DHA nanosuspension.  相似文献   

6.
The aim of the present study was to evaluate and interpret the pharmacokinetic profiles of two compounds after subcutaneous (s.c.) administration. The compounds have similar physicochemical properties, but are a base (BA99) and an acid (AC88), respectively. The compounds were administered as nano- (5 and 500?µmol/kg) and microsuspensions (5?µmol/kg) s.c. to Sprague–Dawley rats. At the low dose, the exposure was higher for both compounds administered as nanocrystals compared to microparticles. The high dose of the compounds resulted in even higher exposure, but not in a dose-linear manner. The differences in exposure between nano- and microparticles were mainly ascribed to higher dissolution rate and improved solubility for smaller particles. In addition to differences in exposure, there were also differences in the elimination pattern. After s.c. injection of 5?µmol/kg of BA99 as nano- and microsuspensions, the elimination profile was similar as observed earlier after oral administration. However, after injection of the higher dose of BA99 and all formulations of AC88, an extended elimination profile was observed, forming a maintained plateau under the investigated time-period. Essentially, constant plasma levels were caused by a balanced equilibrium between total body clearance of the drug and supply rate of drug from the formulations.  相似文献   

7.
The purpose of this study was to investigate the formation of drug nanoparticles from binary and ternary mixtures, consisting of dihydroartemisinin (DHA), a poorly water-soluble antimalarial drug, with water-soluble polymer and/or surfactant. Binary mixtures of drug/polyvinyl pyrrolidone K30 (PVP K30), binary mixtures of drug/sodium deoxycholate (NaDC), and ternary mixtures of drug/PVP K30/NaDC were prepared at different weight ratios and then ground by vibrating rod mill to obtain ground mixtures. Nanosuspension was successfully formed after dispersing ternary ground mixtures or DHA/NaDC ground mixtures in water. The ternary ground mixtures did not give superior nanosuspension in terms of particle size reduction and recovery of drug nanoparticles, but they provided more physically stable nanosuspensions than DHA/NaDC ground mixtures. The size of drug nanoparticles was decreased with increasing grinding time and lowering amount of PVP K30 and NaDC. About 95% of drug nanoparticles were found in the nanosuspension from ternary ground mixtures. Zeta potential measurement suggested that stable nanosuspension was attributable to adsorption of NaDC and PVP K30 onto surface of drug particles. Atomic force microscopy and transmission electron microscopy with selected area diffraction indicated that DHA in nanosuspension was existed as nanocrystals. The obtained nanosuspensions had higher in vitro antimalarial acitivity against Plasmodium falciparum than microsuspensions. The results suggest that co-grinding of DHA with PVP K30 and NaDC seems to be a promising method to prepare DHA nanosuspension.  相似文献   

8.
Various particle sizes of spironolactone as a model low solubility drug were formulated to yield micro-and nanosuspensions of the type solid lipid nanoparticles and DissoCubes. Seven oral and one i.v. formulations were tested in an in vivo pharmacokinetic study in rats with the aim of characterizing the bioavailability of spironolactone on the basis of its metabolites canrenone and 7-alpha-thiomethylspirolactone. In addition, a dose escalation study was carried out using nonmicronized spironolactone suspension as well as a nanosuspension type DissoCubes. On the basis of AUC as well as Cmax ratios, three groups of formulations were distinguished. The biggest improvement was seen with a solid lipid nanoparticle formulation yielding a 5.7-fold increase in AUC for canrenone and a similar improvement based on the Cmax metric, followed by a group of three formulations containing nanosized, micronized, and coarse drug material and surfactant. The DissoCubes nanosuspension yielded highly significant improvements in bioavailability averaging 3.3-fold in AUC and 3.0-fold in terms of Cmax for canrenone. The third class encompasses all other formulations, which showed very little to no improvement in bioavailability. The results show that the particle size minimization was not the major determining factor in the bioavailability improvement. Rather, the type of surfactant used as stabilizer in the formulations was of greater importance. Improvement in drug solubility in the intestine as well as in dissolution rate of spironolactone are the most likely mechanisms responsible for the observed effect, although additional mechanisms such as permeability enhancement may also be involved.  相似文献   

9.
Abstract

The purpose of this paper was to study the influence of drug physicochemical characteristics on in vitro transdermal absorption of hydrophobic drug nanosuspensions. Four drug nanosuspensions were produced by high-pressure homogenization technique, which were the same in stabilizer and similar in particle size. Differential scanning calorimetry and powder X-ray diffraction analysis showed that the crystalline state of the nanocrystals did not change. In vitro permeation study demonstrated that the drug nanosuspensions have a higher rate of permeation that ranged from 1.69- to 3.74-fold compared to drug microsuspensions. Correlation analysis between drug physicochemical properties and Jss revealed that log P and pKa were factors that influenced the in vitro transdermal absorption of hydrophobic drug nanosuspensions, and drugs with a log P value around 3 and a higher pKa value (when pKa?<?pH+2) would gain higher Jss in this paper.  相似文献   

10.
Purpose: The aim of this work was to prepare azithromycin (AZI) nanosuspensions to increase the solubility and dissolution rate.

Method: AZI nanosuspensions were prepared by the combination of reactive precipitation and freeze-drying in presence of biocompatible stabilizer. Formulation and process variables affecting the characteristics of nanosuspensions were optimized. Various tests were carried out to study the physicochemical characteristics of AZI nanosuspensions.

Results: The nanosuspensions were parenterally acceptable and autoclavable, because soybean lecithin was the stabilizer of choice and no organic solvents were used during the preparation. The mean particle size and zeta potential of the AZI nanosuspensions were about 200?nm (±20?nm) and ?36.7 mV (±7.6 mV), respectively. Solid nanoparticles were obtained by lyophilization of the nanosuspensions and nanosuspensions rapidly reconstituted when the nanoparticles were dispersed in water. X-ray diffraction and differential scanning calorimetry analysis showed that the crystal state of nanoparticles was amorphous. Solubility and in vitro release studies indicated that the saturated solubility and dissolution rate increased obviously in comparison of raw AZI. The nanoparticles were physically stable over a period of 5 months as demonstrated by unchanged crystallinity and stable particle size when stored at room temperature and protected from humidity.

Conclusion: The results suggested that reactive precipitation is an effective way to prepare AZI nanosuspensions with increased solubility and dissolution rate.  相似文献   

11.
The purpose of the present study was to prepare itraconazole-loaded chitosan nanosuspension and evaluate it for ocular delivery. Itraconazole-loaded chitosan nanosuspension was prepared by controlled co-precipitation of chitosan and itraconazole from aqueous acetate solution using a combination of pH change and non-solvent addition. The co-precipitated suspension was evaluated for particle size, zeta-potential, entrapment efficiency and solubility study. It was observed that co-precipitation of itraconazole and chitosan from chitosan–lysine system in the presence of Poloxamer-188 as stabiliser provided nanosuspension of the smallest particle size with a 12-fold increase in aqueous saturation solubility of itraconazole and the fastest in vitro release. Transmission electron micrographs of the nanosuspension showed ovoid-shaped particles. A comparative evaluation of the itraconazole (1%, w/v) nanosuspension with commercial itraconazole suspension (1%, w/v) revealed a significantly higher percentage cumulative permeation of itraconazole across the isolated goat cornea from the nanosuspension dosage form as compared to the commercial suspension (P < 0.01).  相似文献   

12.
Objective: To accelerate the determination of optimal spray drying parameters, a “Design of Experiment” (DoE) software was applied to produce well redispersible hesperidin nanocrystals.

Significance: For final solid dosage forms, aqueous liquid nanosuspensions need to be solidified, whereas spray drying is a large-scale cost-effective industrial process.

Methods: A nanosuspension with 18% (w/w) of hesperidin stabilized by 1% (w/w) of poloxamer 188 was produced by wet bead milling. The sizes of original and redispersed spray-dried nanosuspensions were determined by laser diffractometry (LD) and photon correlation spectroscopy (PCS) and used as effect parameters. In addition, light microscopy was performed to judge the redispersion quality.

Results: After a two-step design of MODDE 9, screening model and response surface model (RSM), the inlet temperature of spray dryer and the concentration of protectant (polyvinylpyrrolidone, PVP K25) were identified as the most important factors affecting the redispersion of nanocrystals. As predicted in the RSM modeling, when 5% (w/w) of PVP K25 was added in an 18% (w/w) of hesperidin nanosuspension, subsequently spray-dried at an inlet temperature of 100?°C, well redispersed solid nanocrystals with an average particle size of 276?nm were obtained. By the use of PVP K25, the saturation solubility of the redispersed nanocrystals in water was improved to 86.81?µg/ml, about 2.5-fold of the original nanosuspension. In addition, the dissolution velocity was accelerated.

Conclusions: This was attributed to the additional effects of steric stabilization on the nanocrystals and solubilization by the PVP polymer from spray drying.  相似文献   

13.
ABSTRACT

All-Trans Retinoic Acid (ATRA) nanosuspensions were prepared with a modified precipitation method. The ATRA solution in acetone was injected into pure water by an air compressor under the action of ultrasonication. Photon correlation spectroscopy results showed that the mean particle size of ATRA nanoparticles in nanosuspensions reduced from 337 nm to 155 nm as the injection velocity increased and the polydispersity index was 0.45–0.50. The morphology of ATRA nanoparticles varied with the different concentration of ATRA solution in acetone. ATRA nanoparticles showed an amorphous state and stable in 6 months. It could be concluded that this modified precipitation method could produce stable and controllable ATRA nanosuspension to a certain extent, thus benefit for higher saturation solubility.  相似文献   

14.
15.
Nanotechnology is a promising technique to increase the bioavailability of herbal medicines. This paper presents the nanosuspension approach for increasing the aqueous solubility and thereby bioactivity of important herbal extracts. Nanosuspensions of the seeds of three plants extract (Silybum marianum, Elettaria cardamomum and Coriandrum sativum) were prepared by using polyvinyl alcohol (1.5% w/v) as a stabiliser. Prepared nanoparticles were characterised by scanning electron microscope. Activity of nanosuspension formulation was assessed by using four in vitro antioxidant assays. S. marianum, E. cardamomum and C. sativum particle size was observed to fall in range of 446.1 ± 112.6, 456.63 ± 339.2 and 432.1 ± 172.8 nm, respectively, most of the particles were having spherical shape and smooth topology. These synthesised nanoparticles were found to be more effective against quenching free radical than their crude extracts and standards [butylated hydroxyl toluene and ascorbic acid]. C. sativum nanosuspension showed most free radical scavenging potential against 2,2-diphenyl-1-picrylhdrazyl (DPPH) and superoxide free radical scavenging assays (IC50 0.59 ± 0.01 and 0.81 ± 0.11 mg/ml). S. marianum nanosuspension was found to be most effective against DPPH radicals scavenging (IC50 0.34 ± 0.02 mg/ml). It was concluded that nanosuspension of herbal medicines potentiates the antioxidant potential.  相似文献   

16.
The objective of the present study was to develop stable pellets-layered Simvastatin (SIM) nanosuspensions with improved dissolution and bioavailability. The nanosuspensions were prepared with 7% HPMC, antioxidant 0.03% butylated hydroxyanisole and 0.2% citric acid (m/v) by low temperature grinding. After that, SDS with SIM was in a ratio of 1:5 (m/m), was evenly dispersed in the nanosuspensions. Then, they were layered on the surface of sugar pellets. The mean particle size of the SIM nanosuspensions was 0.74 µm, and 80.6% of the particles was below 1 µm in size. The pellets could re-disperse into nanoparticle status in the dissolution medium. In 900?mL pH 7.0 phosphate solutions, the dissolution of the layered pellets was better than that of commercial tablets. Also, nearly 100% of the drug dissolved from the pellets within 5?min under sink conditions. During the stability studies, SIM pellets exhibited good physical and chemical stability. The relative bioavailability of SIM and Simvastatin β-hydroxy acid (SIMA) for nanosuspensions layered pellets compared with commercial tablets was 117% and 173%, respectively. The bioavailability of SIMA was improved significantly (p < 0.05), confirming the improvement of bioavailability. Thus, the present study demonstrates that the pellet-layered SIM nanosuspensions improved both the dissolution and bioavailability of SIM.  相似文献   

17.
Nanosuspension technology is an attractive approach for the formulation and solubility enhancement of poorly water-soluble drug compounds. The technology requires adequate excipients for stabilizing the suspensions during nanogrinding and storage. This study aimed at establishing a near-infrared (NIR) method for assaying simultaneously the two nanoparticle stabilizers, sodium dodecyl sulphate (SDS) and hydroxypropylcellulose (HPC), in miconazole nanosuspensions. Second derivative of NIR signals was used to establish calibration curves in concentration ranges of interest of SDS (0.03–0.3%) and HPC (0.75–7.5%). The suitability and applicability of the NIR method was verified by evaluating the linearity, accuracy, precision, and specificity of the obtained data. The method was then used to quantify indirectly the amount of SDS and HPC adsorbed onto miconazole nanoparticles. Within the concentration range of interest, SDS adsorption increased up to 122 µg/m2 (4.2?×?10?7 mol/m2) with increasing SDS concentration, and HPC adsorption was in the range of 800–1000 µg/m2 (21–27?×?10?7 mol/m2) for nanosuspensions containing nominally 5% HPC and 12.5% or 20% miconazole. Interestingly, some of the adsorbed HPC was displaced upon increase of SDS concentration and adsorption. The data were also confirmed by surface tension measurements of aqueous solutions of SDS and HPC and nanosuspension supernatants. The availability of a fast and nondestructive method for quantifying simultaneously the adsorption of two stabilizers onto nanoground particles may not only speed up nanosuspension development, but also provide insight into the mechanisms of nanoparticle stabilization regarding competitive adsorption and electrostatic versus steric stabilization.  相似文献   

18.
Nanosuspension technology is an attractive approach for the formulation and solubility enhancement of poorly water-soluble drug compounds. The technology requires adequate excipients for stabilizing the suspensions during nanogrinding and storage. This study aimed at establishing a near-infrared (NIR) method for assaying simultaneously the two nanoparticle stabilizers, sodium dodecyl sulphate (SDS) and hydroxypropylcellulose (HPC), in miconazole nanosuspensions. Second derivative of NIR signals was used to establish calibration curves in concentration ranges of interest of SDS (0.03-0.3%) and HPC (0.75-7.5%). The suitability and applicability of the NIR method was verified by evaluating the linearity, accuracy, precision, and specificity of the obtained data. The method was then used to quantify indirectly the amount of SDS and HPC adsorbed onto miconazole nanoparticles. Within the concentration range of interest, SDS adsorption increased up to 122 μg/m(2) (4.2?×?10(-7) mol/m(2)) with increasing SDS concentration, and HPC adsorption was in the range of 800-1000 μg/m(2) (21-27?×?10(-7) mol/m(2)) for nanosuspensions containing nominally 5% HPC and 12.5% or 20% miconazole. Interestingly, some of the adsorbed HPC was displaced upon increase of SDS concentration and adsorption. The data were also confirmed by surface tension measurements of aqueous solutions of SDS and HPC and nanosuspension supernatants. The availability of a fast and nondestructive method for quantifying simultaneously the adsorption of two stabilizers onto nanoground particles may not only speed up nanosuspension development, but also provide insight into the mechanisms of nanoparticle stabilization regarding competitive adsorption and electrostatic versus steric stabilization.  相似文献   

19.
Purpose: Pranlukast, one of the potential therapeutic tools in the treatment of asthma, has limited clinical applications due to its poor water solubility. The study is aimed to provide a platform for better utilizing pranlukast with enhancement of the dissolution rate and, thus, the oral bioavailability of pranluka’st by preparing nanosuspensions through high-pressure homogenization method.

Method: Poloxamer407 and PEG200 were chosen as stabilizer and surfactant. The formulation was investigated systematically with the dissolution tests as predominant method. Nanosuspensions were prepared by programmed high-pressure homogenization method. The product was characterized by particle size analysis, TEM and XRD are evaluated by in vitro dissolution tests and in vivo absorption examination. In addition, nanosuspensions with only pranlukast were prepared and compared with formulated nanosuspensions.

Results: The optimal values of formulation were 0.5% (w/v) pranlukast with 0.375% (w/v) Poloxamer407, 0.375% (w/v) PEG200 and the screened programming homogenizing procedure parameters were 680 bar for the first 15 circles, 1048 bar for the next 9 circles and 1500 bar for the last 9 circles. Nanosuspensions of 318.2?±?7.3?nm, ?29.3?±?0.8 mV were obtained. The XRD analysis indicated no change of crystalline occurred in the process of homogenization. The in vitro dissolution behavior of nanosuspensions exhibited complete release in 30?min with a remarkable fast dissolution rate. The in vivo bioavailability of formulated pranlukast nanosuspensions demonstrated its enhancement of fast onset of therapeutic drug effects with 4.38-fold improved compared to that of raw crystals.

Conclusion: The study provides a feasible, practical thinking of industry development in the clinical use of pranlukast.  相似文献   

20.
The objective of this study was to develop a tablet formulation of ketoconazole incorporating drug nanoparticles to enhance saturation solubility and dissolution velocity for enhancing bioavailability and reducing variability in systemic exposure. The bioavailability of ketoconazole is dissolution limited following oral administration. To enhance bioavailability and overcome variability in systemic exposure, a nanoparticle formulation of ketoconazole was developed. Ketoconazole nanoparticles were prepared using a media-milling technique. The nanosuspension was layered onto water-soluble carriers using a fluid bed processor. The nanosuspensions were characterized for particle size before and after layering onto water-soluble carriers. The saturation solubility and dissolution characteristics were investigated and compared with commercial ketoconazole formulation to ascertain the impact of particle size on drug dissolution. The drug nanoparticles were evaluated for solid-state transitions before and after milling using differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). This study demonstrated that tablet formulation incorporating ketoconazole nanoparticles showed significantly faster rate of drug dissolution in a discriminating dissolution medium as compared with commercially available tablet formulation. There was no affect on solid-state properties of ketoconazole following milling. The manufacturing process used is relatively simple and scalable indicating general applicability to enhance dissolution and bioavailability of many sparingly soluble compounds.  相似文献   

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