Insoluble breviscapin was chosen as the model drug. Bi-layer osmotic pump technology and gel matrix technology were used to prepare the breviscapin sustained and controlled release preparations. Dissimilarity factors (f1) and similarity factors (f2) were applied as similar judgment index to compare the effects of in vitro conditions on the release behavior of different types of breviscapin sustained and controlled release preparations. The tolerance of in vitro release conditions of bi-layer osmotic pump technology and gel matrix technology were studied. The results showed that in vitro release conditions have a greater impact on the gel matrix sustained release formulations, while have almost no effects on the osmotic pump controlled release formulations. Therefore, osmotic pump controlled release technology is less affected by the drug release environment. And it has a very good application prospect.
Delayed-Action Preparations ; Drug Carriers ; Excipients ; Flavonoids ; administration & dosage ; Hypromellose Derivatives ; Methylcellulose ; analogs & derivatives ; chemistry ; Osmolar Concentration ; Osmosis ; Polyethylene Glycols ; chemistry ; Rotation ; Technology, Pharmaceutical ; methods ; Temperature

Solvents ; chemistry ; Technology, Pharmaceutical ; methods

An application of supercritical fluids technology for processing of budesonide-poly (ethylene oxide) solid dispersions was presented. The correlations of the operation parameters in the preparation process were studied. Solid dispersions of budesonide in poly (ethylene oxide) were prepared using a static method for supercritical carbon dioxide and characterized by powder X-ray diffractometry, differential scanning calorimetry, intrinsic dissolution, and in vitro dissolution. It was found that the optimum condition of solid dispersions formation was as follows: temperature, 40 degrees C ; pressure, 20 MPa; the ratio of budesonide and poly (ethylene oxide) , 1: 10. Drug existed in amorphous state in hydrophilic poly (ethylene oxide) carriers and intrinsic solubility and dissolution rates were significantly enhanced. The mechanism of the enhanced dissolution may be attributed to the amorphous character of the budesonide, improvement of the wettability of the hydrophobic budesonide, together with the formation of hydrogen bond of budesonide and hydrophilic poly (ethylene oxide). The supercritical fluids process can be used as an alternative method for preparation of solid dispersions.
Budesonide ; chemistry ; Calorimetry, Differential Scanning ; Carbon Dioxide ; Chromatography, Supercritical Fluid ; methods ; Drug Carriers ; Ethylene Oxide ; chemistry ; Powders ; Pressure ; Solubility ; Temperature ; Wettability ; X-Ray Diffraction

AIMTo investigate the in vitro influencing factors on drug release from matrices with sodium alginate as the hydrophilic polymer.

METHODSSodium alginate hydrophilic matrix tablets were prepared by direct compression method with theopylline as a model drug. The in vitro influencing factors on drug release behavior from matrices were studied by investigating the swelling, water uptake and erosion characteristics of pure sodium alginate matrices.

RESULTSThe results showed that drug release rate and drug release mechanism were both related to the viscosity of sodium alginate used in matrices, pH values and ionic strength of dissolution media and rotation speeds.

CONCLUSIONSodium alginate can be tailor-made to suit the demands of applicants in sustained delivery systems as a good candidate of hydrophilic polymer.

Alginates ; administration & dosage ; chemistry ; Chemistry, Pharmaceutical ; Delayed-Action Preparations ; Drug Carriers ; Drug Delivery Systems ; Glucuronic Acid ; administration & dosage ; chemistry ; Hexuronic Acids ; administration & dosage ; chemistry ; Hydrogen-Ion Concentration ; Solubility ; Tablets ; Theophylline ; administration & dosage ; chemistry ; Viscosity

The purpose of this study is to design push-pull osmotic pump (PPOP) tablets of famotidine using the expert system for the formulation design of osmotic pump of poor water-soluble drug which had been established by the authors. Firstly, the parameters which were requisite of the system input were obtained from literatures and experimental tests. Then the parameters were input into the system, and the program was run. The system displayed the designed formulations sequential. Finally, famotidine PPOP was prepared according to the designed formulations and the in vitro dissolution was carried out. It was found out that the target formulation of famotidine PPOP which could release for 24 hours was obtained in a very short period. Meanwhile, the practicability of the established expert system was proved.
Delayed-Action Preparations ; Drug Delivery Systems ; methods ; Excipients ; chemistry ; Expert Systems ; Famotidine ; administration & dosage ; chemistry ; Osmosis ; Solubility ; Tablets ; Water

AIMTo investigate the effects of surface modification of lactose carrier on performance of dry powder inhalations (DPIs).

METHODSModified lactose surface was prepared using a "particle smoothing" process to obtain smooth carrier surface and low surface energy with the presence of magnesium stearate, colloidal silica dioxide and talc. Inverse gas chromatography (IGC) was used to assess the surface energy of treated lactose, and the in vitro deposition of carrier-based IFNa-2b DPIs was evaluated with twin stage impinger.

RESULTSThe flowing property of lactose was greatly improved and the surface energy decreased by the "particle smoothing" process. Decreasing surface energy resulted in greater aspiration fraction of IFNa-2b.

CONCLUSIONIGC is a potentially useful tool for rapid formulation design and screening.

Administration, Inhalation ; Chromatography, Gas ; methods ; Drug Carriers ; administration & dosage ; chemistry ; Interferon-alpha ; administration & dosage ; chemistry ; Lactose ; administration & dosage ; chemistry ; Particle Size ; Powders ; Recombinant Proteins ; Stearic Acids ; chemistry ; Surface Properties ; Talc ; chemistry ; Technology, Pharmaceutical ; methods

Objective To analyse the characterisitics of daily blood glucose profiles of insulinoma using continuous glucose monitoring system(CGMS) and to investigate the value of CGMS in the diagnosis of insulinoma. Methods The blood glucose of 6 patients with pathologically-confirmed insulinoma(insulinoma group) were detected by CGMS for 3 consecutive days.The mean blood glucose(MBG),M-value of Schlichtkrull(M-value),frequency distribution of glucose levels and the hypoglycemic episodes of CGMS were measured,and the results were compared with those of normal glucose regulation(n=6,control group) and patients with newly-diagnosed type 2 diabetes with reactive hypoglycemia(n=5,diabetes group). Results The M-value of insulinoma group was significantly higher than that of control group(P0.05).The M-value and MBG of diabetes group were higher than those of insulinoma group and control group(P

Objective To assay serum apelin level in obesity and newly-diagnosed type 2 diabetes mellitus (DM) patients and investigate the relationship between serum apelin level and body fat parameter,glucose and lipid metabolism and insulin resistance index,etc.Methods Sixty-two patients with type 2 DM and 72 subjects with normal glucose regulation (NGR) were selected and each group was divided into obese and non-obese subgroups according to body mass index (BMI)≥25 kg/m~2 or

To study the in situ intestinal absorption kinetics of flrubiprofen in rats, the absorption of flurbiprofen in small intestine (duodenum, jejunum and ileum) and colon of rats was investigated using in situ single-pass perfusion method and the drug content was measured by HPLC. The effects of drug concentration on the intestinal absorption were investigated. The K(a) and P(app) values of flurbiprofen in the small intestine and colon had no significant difference (P > 0.05). Drug concentration (4.0, 10.0 and 16.0 mg x L(-1)) had no significant influence on the K(a) values (P > 0.05). However, when concentration was 4.0 mg x L(-1) and 10.0 mg x L(-1), significant effect on the P(app) values (P < 0.05) was found, but significant effect on the P(app) values was not shown between 10.0 mg x L(-1) and 16.0 mg x L(-1) (P > 0.05). The K(a) and P(app) values of flurbiprofen on the perfusion flow rate had significant difference (P < 0.05). Flurbiprofen could be absorbed at all segments of the intestine in rats and had no special absorption window. The absorption of flurbiprofen complies with the facilitated diffusion in the general intestinal segments, and accompany with the cytopsistransport mechanism probably. The perfusion flow rate had significant effect on the K(a) and P(app).
Analgesics ; administration & dosage ; pharmacokinetics ; Animals ; Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; pharmacokinetics ; Colon ; metabolism ; Dose-Response Relationship, Drug ; Duodenum ; metabolism ; Female ; Flurbiprofen ; administration & dosage ; pharmacokinetics ; Ileum ; metabolism ; Intestinal Absorption ; Jejunum ; metabolism ; Male ; Perfusion ; Rats ; Rats, Sprague-Dawley

The three-step dissolution experiment was established to investigate the in vitro release of budesonide colon-specific tablet and to elucidate the drug release mechanism by fitting to different mathematical models. The physiological parameters of stomach, small intestine and colon such as pH value, intestinal flora, specific organic enzyme, vermiculation and conveying time were mimicked to plot the in vitro dissolution, separately. Sample were taken at predetermined time intervals in 24 h and the accumulated drug releases were determined by using HPLC method. Drug release curves of the localization tablets were fitted to various mathematical models. It shows that no drug release was found in 2 h. About 5% release was determined after 6 h while 77.5% accumulated release was reached within 24 h. Drug release from the in house formulation fitted well into first-order model. The three-step dissolution method could be used to evaluate the colon-specific characteristics of budesonide colonic localization tablet. The drug release behavior of the localization tablet conforms to the drug release mechanisms of controlled porosity osmotic pump where osmotic pressure is the main driving force for controlled delivery of drugs.
Animals ; Anti-Inflammatory Agents ; administration & dosage ; pharmacokinetics ; Budesonide ; administration & dosage ; pharmacokinetics ; Colon ; metabolism ; Delayed-Action Preparations ; Drug Carriers ; Drug Compounding ; Drug Delivery Systems ; methods ; Excipients ; Hydrogen-Ion Concentration ; In Vitro Techniques ; Intestinal Secretions ; Models, Theoretical ; Rats ; Tablets