Sleep Deprivation Induces Dry Eye Through Inhibition of PPARα Expression in Corneal Epithelium.

Purpose: To determine if sleep deprivation induces dry eye through altering peroxisome proliferator-activated receptor alpha (PPARα) expression in mice.

Methods: The "stick over water" sleep deprivation-induced dry eye (SDE) model evaluated PPARα involvement in inducing this condition. Scanning electron microscopy (SEM) examined microvilli morphology in superficial corneal epithelial cells (SCECs) in SDE and PPARα-/- mice.

[The swelling behavior of choline fenofibrate hydrogel matrix tablets using dynamic image analysis].

The purpose of this study is to investigate the effects of formulation on the swelling behavior of choline fenofibrate hydrogel matrix tablets and reveal the relation between swelling property and release profile using dynamic image analysis. The volume swelling ratio (SR) and height/width (k) could evaluate the swelling behavior of matrix tablets well. The mount of hydroxypropyl methylcellulose (HPMC) and the ratio between K15M and K4M affected the volume swelling ratio, while PVP didn’t.

[Preparation and properties of thermosensitive in situ gel for ophthalmic formulation containing pearl hydrolyzate].

The study was designed to generate an ophthalmic thermosensitive in situ gel with improved mechanical and mucoadhesive properties that may prolong the retention time to enhance the bioavalability of pearl hydrolyzate. The gene was comprised of poloxamer 407, poloxamer188 and Carbopol 934, which were optimized by central composite design and response surface methodology. The rheological properties, transcorneal permeability, retention time and in vitro release behaviors of the optimal gel formulation were investigated.

[Determination of contact angle of pharmaceutical excipients and regulating effect of surfactants on their wettability].

To study the effects of surfactants on wettability of excipients, the contact angles of six types of surfactants on the surface of two common excipients and mixture of three surfactants with excipients were measured using hypsometry method. The results demonstrated that contact angle of water on the surface of excipients was associated with hydrophilcity of excipients. Contact angle was lowered with increase in hydrophilic groups of excipient molecules.

[The rheology properties of common hydrophilic gel excipients].

To investigate theological properties of common hydrophilic gel excipients such as Carbopol based on viscosity, the viscosity was determined by rotation method and falling-ball method. Linear regression was made between ln(eta) and concentration, the slope of which was used to explore the relation between viscosity and concentration of different excipients. The viscosity flow active energy (E(eta)) was calculated according to Arrhenius equation and was used to investigate the relation between viscosity and temperature of different excipients.

To enhance the efficiency of nefopam transdermal iontophoresis by using a novel method based on ion-exchange fiber.

Background: In the system of the iontophoresis, the external electric field made the ions in the system moving directly, then, the current was generated. Because the current was contributed by all ions in the system, and the small ions with large amount often had higher conductibility than the drug ions, the fraction of the total current contributed by the drug ions was often low. It was the main reason for the generally low efficiency of the transdermal iontophoretic drug delivery.

[The preparation and kinetic study on enzymatically-controlled drug release of isotretinoin/amylose inclusion complex].

The inclusion complex of isotretinoin was prepared by sealed-control temperature method and amylose was used as carrier. The formation of inclusion complex was confirmed by powder X-ray diffraction and DSC. The equation of enzymatically-controlled drug release was established by kinetic theory, and the release characteristic of drug was confirmed by using the kinetic equation.

Ibuprofen ion-exchange fiber complex: improved dissolution and gastric tolerance based on ion exchange.

The purpose of the present study is to develop a novel method to improve the dissolution of water-insoluble drug ibuprofen and the gastric tolerance of this non-steroidal anti-inflammatory drug which has potentially serious gastrointestinal side effects. This method is based on ion exchange of ion-exchange fibers. Water-insoluble drug ibuprofen was dispersed in deionized water, and then the ion-exchange fibers in OH(-) type was immersed in it.

Ketoconazole ion-exchange fiber complex: a novel method to reduce the individual difference of bioavailability in oral administration caused by gastric anacidity.

Water insoluble faintly alkaline drugs often have potential absorption problem in gastrointestinal tract in oral administration for patients with gastric anacidity. The purpose of the present study is to develop a novel method to improve the absorption of the water insoluble faintly alkaline drug in peroral administration. This method is based on ion exchange of ion-exchange fibers.

A novel method to enhance the efficiency of drug transdermal iontophoresis delivery by using complexes of drug and ion-exchange fibers.

The main reason for generally low efficiency of the transdermal iontophoretic drug delivery is that the fraction of the total current contributed by the drug ions is very small. The objective of this study was to find a method to increase the fraction of the total current contributed by the drug ions so as to enhance the drug's iontophoretic delivery. Iontophoretic transport of diclofenac solution and diclofenac assisted by ion exchange materials, including ion-exchange resin, ion-exchange membrane and ion-exchange fiber, across the rat skin were investigated.

Modulating drug loading and release profile of beta-cyclodextrin polymers by means of cross-linked degree.

The purpose of the present study is to use beta-cyclodextrin polymers (beta-CDP) with different cross-linked degree (CLD) to form inclusion complexes with ibuprofen and examine the effects of structural and compositional factors of beta-CDP on its drug loading and release behaviors. A series of beta-CDP with different CLD were synthesized and characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and 13C NMR spectrum. The beta-CDP was systemically characterized for the relation between the CLD of beta-CDP and the drug loading and release as well.

Investigation into the potential of electroporation facilitated topical delivery of cyclosporin a.

Purpose: The potential for electroporation-facilitated topical transport of cyclosporin A (CysA) was investigated using rat skin.

Methods: Studies of various electrical factors acting on the deposition of CysA into the stratum corneum and deeper skin of in vitro electroporation were performed. We also tested the synergistic effect of electroporation and other approaches such as chemical enhancers and low-frequency ultrasound on topical drug delivery of CysA.

[Kinetic study on dissociation of amylose/salicylic acid compound using non-isothermal method].

The inclusion compound of amylose and salicylic acid (SA) was prepared by a sealed temperature control method, and the formation of the inclusion compound was confirmed by IR spectrum and powder X-ray diffraction. The kinetic parameters of dissociation of amylose/SA compound were studied by the nonisothermal method which was defined as a relationship between the dissociation ratio and time. The values of activation energy (Ea) and frequency factors (InA) were calculated by a nonlinear least-square method.

Pharmacokinetics of clarithromycin citrate salt after oral administration to beagle dogs and food effects on its absorption.

To investigate the pharmacokinetics of clarithromycin citrate salt and the effect of food on the absorption of free base and citrate salt, clarithromycin citrate was prepared and the in vitro intrinsic dissolution profiles of the free base and the salt were examined at pH 5.0 and pH 6.8.

Pharmacokinetic studies of meloxicam following oral and transdermal administration in Beagle dogs.

Aim: The potential for topical delivery of meloxicam was investigated by examining its pharmacokinetic profiles in plasma and synovial fluid following oral and transdermal administration in Beagle dogs.

Methods: The experiment was a two-period, crossover design using 6 Beagle dogs. Meloxicam tablets were administered orally at a dose of 0.

Development and evaluation of a pH-dependent sustained release tablet for irritable bowel syndrome.

The overall objective of this study was to develop a pH-dependent sustained release tablet formulation of a model drug, tegaserod maleate (TM), which is a poorly water soluble and acid labile drug in gastric milieu. The formulation's goal was to allow the dosage form to pass through the stomach intact, start disintegrating in the upper small intestine and slowly release the active in a controlled manner. Partition coefficient, contact angle and drug-excipient compatibility were investigated as part of the preformulation studies.

Cloud point extraction-HPLC method for determination and pharmacokinetic study of flurbiprofen in rat plasma after oral and transdermal administration.

A method based on cloud-point extraction (CPE) was developed for the determination of flurbiprofen (FP) in rat plasma after oral and transdermal administration by high-performance liquid chromatography coupled with UV detection (HPLC-UV). The non-ionic surfactant Genapol X-080 was chosen as the extract solvent. Variables parameter affecting the CPE efficiency were evaluated and optimized.

[LC-MS/MS determination of budesonide in dog plasma].

A liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of budesonide in dog plasma. Budesonide and the internal standard triamcinolone acetonide were separated from plasma by alkalinized liquid-liquid extraction with ethyl acetate. Chromatographic separation was performed on a Capcell Pak C18 MG column with the mobile phase consisted of acetonitrile -5 mmol x L(-1) ammonium acetate (60:40, v/v) at a flow-rate of 0.

In vitro and in vivo evaluation of tegaserod maleate pH-dependent tablets.

The purpose of this study was to prepare tegaserod maleate (TM) pH-dependent tablets and evaluate their advantages as a sustained release delivery system. TM, insoluble in water and unstable in gastric milieu, was formulated into pH-dependent tablets coated with combinations of two methacrylic acid copolymers - Eudragit L100 and Eudragit S100. The influence of core tablet compositions, polymer combination ratios and coating levels on the in vitro release rate of TM from coated tablets was investigated.

Preparation and evaluation of Ibuprofen solid dispersion systems with kollidon particles using a pulse combustion dryer system.

Solid dispersions (SDs) of ibuprofen (IBU) were prepared with four carriers: Kollidon 25, Kollidon 30, Kollidon VA64, and Kollidon CL, using a newly developed pulse combustion dryer system, HYPULCON. Physicochemical properties of the SDs obtained were investigated by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), scanning electron microscope (SEM), and Fourier transformation IR spectroscopy (FT-IR). Powder X-ray diffraction (PXRD) showed that the crystal diffraction peaks of IBU in SDs disappeared completely, and in differential scanning calorimetry (DSC) curves, the endothermic peaks of IBU in SDs were not observed.

[The delivery mechanism of micro-porous osmotic pump tablets].

To investigate the delivery mechanism of micro-porous osmotic pump tablets ( MPOP), taking tramadol hydrochloride ( TR) as the model drug, tramadol hydrochloride micro-porous osmotic pump tablets (TR MPOP) were prepared with compressible starch as diluent, cellulose acetate as coating material, polyethylene glycol 400 as pore-forming agents. The equilibrium solubility and osmolality of TR were determined. The effects of fillers in tablet cores, coating levels, and osmotic pressures of release media on expansion behavior of preparations were described.

Investigation of microemulsion system for transdermal delivery of meloxicam.

A new oil-in-water microemulsion containing 0.375% meloxicam was developed in order to improve the skin permeability of meloxicam. Among various surfactants and cosurfactants investigated in the microemulsion system, polyoxyethylene sorbitan trioleate (Tween 85) showed excellent solubility and ethanol expressed skin permeation enhancing effect for meloxicam.

[Determination of salidroside and p-tyrosol in Hongjingtian for injection(freezing-dry) by SPE-HPLC].

Objective: To assay salidroside and p-tyrosol in Hongjingtian for injection (freezing-dry).

Method: Samples were purified by Sep-Pak C18 column and salidroside and p-tyrosol were determined by HPLC with Irregular-H C18 (4.6 mm x 250 mm, 5 microm), and eluted with a mobile phase of methanol-acenitonitrile -0.

Evaluation of in-vitro dissolution and in-vivo absorption for two different film-coated pellets of clarithromycin.

The aim of this study was to compare two formulations of film-coated pellets containing clarithromycin after single oral dose study in healthy male volunteers. Two formulations with different coating polymers were prepared: formulation-1 (F-1) was prepared by incorporating three kinds of pH-dependent gradient-release coated pellets into capsules and formulation-2 (F-2) was prepared by coated with an insoluble semiosmotic film. Release profiles of film-coated pellets were evaluated using paddle method under different conditions.

[Effect of solution viscosity on polymer precorneal residence time evaluated by in vitro method].

Aim: To evaluate how solution viscosity affects the precorneal residence of five water-soluble polymers with different properties.

Methods: Captive bubble technique was used, with the consecutive change of contact angle interpreted as an indication of desorption process, to study the residence of those polymers in vitro on freshly enucleated rabbit eyes under physiological conditions.

Results: Carbopol and sodium hyaluronate (HA), which adsorbed to isolated ocular surface more than 15 min, showed the optimum precorneal retentive capabilities.