Xiaxia Shen

Oral fast-dissolving drug delivery membranes prepared from electrospun polyvinylpyrrolidone ultrafine fibers

Oral fast-dissolving drug delivery membranes (FDMs) for poorly water-soluble drugs were prepared via electrospinning technology with ibuprofen as the model drug and polyvinylpyrrolidone (PVP) K30 as the filament-forming polymer and drug carrier. Results from differential scanning calorimetry, x-ray diffraction, and morphological observations demonstrated that ibuprofen was distributed in the ultrafine fibers in the form of nanosolid dispersions and the physical status of drug was an amorphous or molecular form, different from that of the pure drug and a physical mixture of PVP and ibuprofen. Fourier-transform infrared spectroscopy results illustrated that the main interactions between PVP and ibuprofen were mediated through hydrogen bonding. Pharmacotechnical tests showed that FDMs with different drug contents had almost the same wetting and disintegrating times, about 15 and 8 s, respectively, but significantly different drug dissolution rates due to the different physical status of the drug and the different drug-release-controlled mechanisms. 84.9% and 58.7% of ibuprofen was released in the first 20 s for FDMs with a drug-to-PVP ratio of 1:4 and 1:2, respectively. Electrospun ultrafine fibers have the potential to be used as solid dispersions to improve the dissolution profiles of poorly water-soluble drugs or as oral fast disintegrating drug delivery systems.

Electrospun diclofenac sodium loaded Eudragit® L 100-55 nanofibers for colon-targeted drug delivery

Eudragit® L 100-55 nanofibers loaded with diclofenac sodium (DS) were successfully prepared using an electrospinning process, and characterized for structural and pharmacodynamic properties. The influence of solvent and drug content on fiber formation and quality was also investigated. Fiber formation was successful using a solvent mixture 5:1 (v/v) ethanol:DMAc. XRD and DSC analysis of fibers confirm electron microscopic evidence that DS is evenly distributed in the nanofibers in an amorphous state. FTIR analysis indicates hydrogen bonding occurs between the drug and the polymer, which accounts for the molecular integration of the two components. In vitro dissolution tests verified that all the drug-loaded Eudragit® L 100-55 nanofibers had pH-dependent drug release profiles, with limited, less than 3%, release at pH 1.0, but a sustained and complete release at pH 6.8. This profile of properties indicates drug-loaded Eudragit® L 100-55 nanofibers have the potential to be developed as oral colon-targeted drug delivery systems.

Time-engineeringed biphasic drug release by electrospun nanofiber meshes

A drug-loaded nanofiber mesh which could achieve time-engineeringed biphasic release was fabricated through sequential electrospinning. The drug to polymer ratio of each single mesh was allocated and designed before the tri-layered meshes were created. The resultant meshes had the following construction: (i) the first drug-loaded mesh (top side), (ii) the second drug-loaded mesh (second side), and (iii) the third drug-loaded mesh (bottom side). The drug release speed and duration were controlled by designing morphological features of the electrospun meshes such as the fiber diameter and mesh thickness. An in vitro release experiment revealed that the tri-layered construction with distinct morphological features of each component mesh can provide biphasic drug release. The time-engineeringed dual release system using the multilayered electrospun nanofiber meshes was proved to be a useful formulation when achieving controlled drug release at different times.

Novel oral fast-disintegrating drug delivery devices with predefined inner structure fabricated by Three-Dimensional Printing.

Objectives Novel fast‐disintegrating drug delivery devices with special inner structure characteristics were designed and fabricated using Three‐Dimensional Printing.

Solid Dispersions of Ketoprofen in Drug-Loaded Electrospun Nanofibers

Solid dispersions of ketoprofen in nanofibers were prepared using electrospinning process with polyvinylpyrrolidone as the filament-forming polymer. Results from differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and fourier-transform infrared suggested that ketoprofen was well distributed in the polymer nanofibers in an amorphous solid dispersion state due to the hydrogen bonding between them. In vitro wetting and dissolution tests showed that the nanofibers could absorb water from the wet papers and wetted within several seconds, and ketoprofen could be exhausted within 30 seconds. Electrospinning is a useful process for the preparation of solid dispersions.

Electrospun zein–PVP fibre composite and its potential medical application

Abstract Electrospun zein–polyvinylpyrrolidone (PVP) ultrafine fibres containing varying polymer ratios were prepared and characterised. Ketoprofen was used as a model drug incorporated into the polymer system. The fibre morphologies, the composite physical states and their interactions were investigated using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Scanning electron microscopy observations revealed that ketoprofen was well distributed in the polymer matrix. Both the surface and cross-sections of fibres were homogeneous, although they characteristically became rounder as the content of PVP in the composite increased. Results from FTIR, DSC and XRD suggested that ketoprofen exist as an amorphous solid dispersion state in the matrix. The influence of zein-to-PVP content on the drug release profiles was investigated using in vitro dissolution tests under controlled conditions. The results prove that ketoprofen release rates increased at a higher PVP level. The present research demonstrates that zein can be introduced into a fibre composite that effectively has the potential to act as matrix for drug release. This is the first report of zein acting in this context.

Preparation and characterization of TAM-loaded HPMC/PAN composite fibers for improving drug-release profiles.

The present paper reports the preparation and characterization of composite hydroxypropyl methylcellulose/polyacrylonitrile (HPMC/PAN)-medicated fibers via a wet spinning technique. Tamoxifen (TAM) was selected as a model drug. Numerous analyses were conducted to characterize the mechanical, structure and morphology properties of the composite fibers. The drug content and in vitro dissolution behavior were also investigated. SEM images showed that the TAM-loaded HPMC/PAN composite fibers had a finger-like outer skin and a porous structure. FT-IR spectra demonstrated that there was a good compatibility between polymer and drug. Results from X-ray diffraction and DSC suggested that most of the incorporated TAM was evenly distributed in the fiber matrix in an amorphous state, except for a minority that aggregated on the surface of fibers. The drug content in the fibers was lower than that in the spinning solution and about 10% of TAM was lost during spinning process. In vitro dissolution results indicated that, compared to TAM–PAN fibers, HPMC/PAN composite systems had weaker initial burst release effects and more drug-loading. The combination of hydrophilic polymer HPMC with PAN could improve the performance of polymer matrix composite fibers in regulating the drug-release profiles.

Wet-Spinning Medicated PAN/PCL Fibers for Drug Sustained Release

Fine and continuous ibuprofen-loaded PAN/PCL fibers were successfully prepared using wet spinning processes. The co-dissolving method was employed to prepare the spinning solution. The prepared filaments had a diameter of 131 plusmn 24 mum. The drug content in the fibers was found to be a little lower than that in the spinning liquid, 10.7% of the drug was lost during the spinning processes. Polarized optical images showed that the drug molecular aggregated together from the spinning solutions to form fine particles on the fiber surface. In vitro dissolution tests indicated that the initial burst effect was clear. 21.64% of the total drug contained in the fibers was released during the test periods of 15 days. The medicated fibers had a potential usage for preparing transdermal drug delivery systems.

Applications of Polarization Microscope in Determining the Physical Status of API in the Wet-Spinning Drug-Loaded Fibers

The API (Active Pharmaceutical Ingredients) physical status and distributions in the drug-loaded fibers have a manifest influence on the drug-loaded capabilities and drug-released controlled properties. In the present study, an easy and useful method was developed for determining the drug physical status and distributions in the wet spinning API-loaded fibers. The fibers prepared from co-dissolved wet spinning methods were observed under orthogonal polarized light. The results demonstrated that the API in the fibers lost its original needle crystal shape, double refraction features and natural polychrome, but transferred to tiny white circular particles and evenly distributed on the fibers’ surface. The results from scanning electron microscope and X-ray diffraction analysis were basically concurred with those observations, illustrating the availability of polarization microscope observations. Polarization microscopy is a simple and useful method for the development of novel drug-loaded fibers.

Polyacrylonitrile/Kaolinite Hybrid Nanofiber Mats Aimed for Treatment of Polluted Water

The present study provides the methods of preparing organic/inorganic hybrid nanofiber mats. A simple process was developed in preparing polyacrylonitrile/kaolinite hybrid nanofiber mats based on electrospinning technology. The electrospinning of sub-nano kaolinite particles-contained PAN suspensions resulted in uniform distribution of kaolinite particles among the PAN nanofibers, which was demonstrated by scanning electron microscope and optical polarized microscope. However, FTIR results indicated that some interactions between PAN and kaolinite existed, which was useful for the stability of kaolinite-contained suspensions and the even distribution of kaolinite in the PAN nanofiber mats. The as-prepared hybrid nanofiber mats may find well applications in the treatment of phenol polluted water and heavy metal polluted water.