Nerve growth factor-basic fibroblast growth factor poly-lactide co-glycolid sustained-release microspheres and the small gap sleeve bridging technique to repair peripheral nerve injury

We previously prepared nerve growth factor poly-lactide co-glycolid sustained-release microspheres to treat rat sciatic nerve injury using the small gap sleeve technique.Multiple growth factors play a synergistic role in promoting the repair of peripheral nerve injury;as a result,in this study,we added basic fibroblast growth factors to the microspheres to further promote nerve regeneration.First,in an in vitro biomimetic microenvironment,we developed and used a drug screening biomimetic microfluidic chip to screen the optimal combination of nerve growth factor/basic fibroblast growth factor to promote the regeneration of Schwann cells.We found that 22.56 ng/mL nerve growth factor combined with 4.29 ng/mL basic fibroblast growth factor exhibited optimal effects on the proliferation of primary rat Schwann cells.The successfully prepared nerve growth factor-basic fibroblast growth factor-poly-lactide-co-glycolid sustained-release microspheres were used to treat rat sciatic nerve transection injury using the small gap sleeve bridge technique.Compared with epithelium sutures and small gap sleeve bridging alone,the small gap sleeve bridging technique combined with drug-free sustained-release microspheres has a stronger effect on rat sciatic nerve transfection injury repair at the structural and functional level.

Combustion Characteristics of Solid Sustained-Release Energetic Materials

A solid sustained-release energetic material sample,an eruption device and a complete test system were prepared further to analyse the combustion characteristics of solid sustainedrelease energetic materials.The high-temperature heat flux generated by the combustion of the samples from the eruption device was used to penetrate the Q235 target plate.In addition,the meaning and calculation formula of energy density characterising the all-around performance of heat flux were proposed.The numerical simulation of the combustion effect of samples was carried out.According to the data comparison,the numerical simulation results agreed with the experimental results,and the maximum deviation between the two was less than 8.9%.In addition,the structure of the combustion wave and high-temperature jet was proposed and analysed.Based on theoretical analysis,experimental research and numerical simulation,the theoretical burning rate formula of the sample was established.The maximum error between the theoretically calculated mass burning rate and the experimental results was less than 9.8%.Therefore,using the gas-phase steady-state combustion model to study the combustion characteristics of solid sustained-release energetic materials was reasonable.The theoretical burning rate formula also had high accuracy.Therefore,the model could provide scientific and academic guidance for the theoretical research,system design and practical application of solid sustained-release energetic materials in related fields.

格列奇特(Gliclazide)治疗Ⅱ型糖尿病的临床观察

本文对30例单纯饮食治疗不理想的Ⅱ型糖尿药患者用山东省医药工业研究所提供的新药格列奇特(gliclzzide,甲磺吡脲,国产达美康治疗3～6个月。开始剂量为160mg/d,2～3周后根据血、尿糖情况调整为80～240mg/d。治疗有效者治疗后的空腹血糖、餐后2h血糖、24h尿糖定量及糖化血红蛋白均较冶疗前有明显下降(p【0.01)。

Improvement of Dissolution Rate of Gliclazide Using Solid Dispersions with Aerosil 380 and Its Effect on Alloxan Induced Diabetic Rats

The main objective of this research is to conduct a comprehensive study for enhancing the aqueous solubility of poorly water soluble gliclazide using hydrophilic fumed silica particles (Aerosil®380) and evaluating the influence of silica on drug release profile and pharmacological activity on alloxan induced diabetic rats. Solid dispersions (SD’s) of gliclazide were prepared using solvent evaporation method. The dissolution profiles and solid state characterization of the SD’s prepared were all evaluated. The dissolution rate of gliclazide in the SD’s with fumed silica (weight ratio, 1:1) was approximately 38%, which is about 10 fold higher than that of the pure drug after 30 min. After forming the SD’s, gliclazide changed into an amorphous state, which can infer from differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). Fourier transform infrared spectroscopy (FTIR) also revealed the formation of weak hydrogen bonding through the interactions between the secondary amine groups of gliclazide and silanol groups of silica particles in the SD’s. The rapid dissolution rate from the SD’s might be attributed to the amorphization of drug, improved specific surface area and wettability than the original drug crystals. Further, we investigated the antidiabetic effects of SD’s of gliclazide in alloxan induced diabetic rats. The SD’s of gliclazide decrease the blood glucose level 64% whereas the conventional gliclazide decreases only 37% in diabetic rats. Lipid profiles, kidney and liver functions are remarkably improved in diabetic rat treated with SD’s of gliclazide than that of conventional gliclazide. These results suggest that SD’s of gliclazide have much more bioavailability and hence are more pharmacologically active than that of conventional gliclazide form.

Methylprednisolone microsphere sustained-release membrane inhibits scar formation at the site of peripheral nerve lesion

Corticosteroids are widely used for the treatment of acute central nervous system injury. However, their bioactivity is limited by their short half-life. Sustained release of glucocorticoids can prolong their efficacy and inhibit scar formation at the site of nerve injury. In the present study, we wrapped the anastomotic ends of the rat sciatic nerve with a methylprednisolone sustained-release membrane. Compared with methylprednisone alone or methylprednisone microspheres, the methylprednisolone microsphere sustained-release membrane reduced tissue adhesion and inhibited scar tissue formation at the site of anastomosis. It also increased sciatic nerve function index and the thickness of the myelin sheath. Our findings show that the methylprednisolone microsphere sustained-release membrane effectively inhibits scar formation at the site of anastomosis of the peripheral nerve, thereby promoting nerve regeneration.

Release performance and sustained-release efficacy of emamectin benzoate-loaded polylactic acid microspheres

High-performance liquid chromatography （HPLC） was employed to determine drug release rates based on emamectin benzoate concentrations in the medium. Release kinetics equations were used to fit the drug release behavior. The effects of particle size and release medium pH on the release rate were also investigated. The indoor toxicity of emamectin benzoate-loaded polylactic acid microspheres on the diamondback moth larva （Plutella xylostella） was studied to explore drug sustained-release performance. In acidic and neutral media, the drug release behavior of the microspheres was in accord with the first-order kinetics equation. Increasing the spray dosage of emamectin benzoate-loaded polylactic acid microspheres initially resulted in an equivalent insecticidal efficacy with the conventional emamectin benzoate microemulsion. However, the drug persistence period was four-fold longer than that observed using the conventional formulation. The developed emamectin benzoate-loaded polylactic acid microspheres showed dramatic sustained-release performance. A treatment threshold of greater than 35 mg mL-1 was established for an efficient accumulated release concentration of emamectin benzoate-loaded microspheres.

The preparation and the in-vitro pharmacodynamics study of the intracapsular sustained-release preparations for the prevention of posterior capsule opacification

Docetaxel-loaded sustained-release preparation based on 2-Hydroxyethyl methacrylate(HEMA)and Methyl methacrylate(MMA)cross-linked copolymer(P(HEMA-co-MMA))was prepared to examine the potential use for preventing posterior capsule opacification(PCO).The preparations were prepared by polymerizing the mixture of HEMA,MMA,cross-linking agent(EGDMA),initiator(AIBN)and docetaxel.The influence factors and mechanism of drug release were studied in the experiments.FT-IR,X-RD and SEM methods were used to characterize the polymer(P(HEMA-co-MMA))and docetaxel-loaded sustained-release preparations.Biocompatibility of P(HEMA-co-MMA)and in-vitro effect of docetaxel-loaded sustained-release preparations were also evaluated.The results showed that docetaxel could release sustainedly from these preparations prepared by cross-linking polymerization.And the release rate could be accelerated by increasing the MMA ratio or EGDMA ratio of the polymer.Release mechanism of docetaxel fitted the Higuchi model well.The results of IR and X-RD showed that only a hydrogen bond was formed between docetaxel and P(HEMA-co-MMA).Docetaxel dispersed in P(HEMA-co-MMA)in amorphous form.The elution test showed that P(HEMA-co-MMA)had good biocompatibility and the in-vitro pharmacodynamics study proved that docetaxel could release stably from the preparations and inhibit HLECs’proliferation.The docetaxel-loaded sustained-release preparations proved to be a promising therapy for preventing PCO.These results also lay a theoretical and experimental foundation for the future.

Application of D-Optimal Study Design with Contour Surface Response for Designing Sustained Release Gliclazide Matrix Tablets

An optimized formulation of a sustained release tablet of Gliclazide was developed. The use of Doptimal design with a polynomial statistical model to analyze dissolution data reduced the number of laboratory tests required to obtain an optimal dosage form. The final formulation contained 22 mg of Methocel&regE15LV, 16.5 mg Methocel&regE15 and 10.0 mg of Dibasic Calcium Phosphate per 30 mg Gliclazide sustained release tablet. Dissolution studies performed on tablets from 5000 tablet test batches released greater than 90 percent of loaded drug in eight hours. Drug release from the optimized tablets followed a pattern more closely similar to zero-order than other mechanisms of drug release tested. Storage of tablets in accelerated and ambient conditions for 6 and 12 months respectively did not alter any of the physico-chemical properties, drug release or the drug release rate compared to initial observations and dissolution data of the prepared tablets. The addition of potassium phosphate and monosodium phosphate to the tablet reduced the effect pH has on Gliclazide dissolution compared to the commercially available product.

Tunable and sustained-release characteristics of venlafaxine hydrochloride from chitosan–carbomer matrix tablets based on in situ formed polyelectrolyte complex film coating

The objective of this study is to design sustained-release tablets using matrix technology, which can well control the release of highly water-soluble drugs with good system robustness and simple preparation process. Taking venlafaxine hydrochloride(VH) as a drug model, the feasibility of using chitosan(CS), carbomer(CBM) combination system to achieve this goal was studied. Formulation and process variables influencing drug release from CS–CBM matrix tablets were investigated. It was found that CS–CBM combination system weakened the potential influence of CS, CBM material properties and gastric emptying time on drug release profile. Demonstrated by direct observation, differential scanning calorimetry(DSC) and Fourier transform infrared spectroscopy(FTIR), in situ self-assembled polyelectrolyte complex(PEC) film was formed on the tablet surface during gastrointestinal tract transition, which contributed to the tunable and robust control of drug release. The sustained drug release behavior was further demonstrated in vivo in Beagle dogs, with level A in vitro and in vivo correlation(IVIVC) established successfully. In conclusion, CS–CBM matrix tablets are promising system to tune and control the release of highly water-soluble drugs with good system robustness.

Preparation and evaluation of tamsulosin hydrochloride sustained-release pellets modified by two-layered membrane techniques

The aim of the present study was to develop tamsulosin hydrochloride sustained-release pellets using two-layered membrane techniques.Centrifugal granulator and fluidizedbed coater were employed to prepare drug-loaded pellets and to employ two-layered membrane coating respectively.The prepared pellets were evaluated for physicochemical characterization,subjected to differential scanning calorimetry(DSC)and in vitro release of different pH.Different release models and scanning electron microscopy(SEM)were utilized to analyze the release mechanism of Harnual■ and home-made pellets.By comparing the dissolution profiles,the ratio and coating weight gain of Eudragit■ NE30D and Eudragit■ L30D55 which constitute the inside membrane were identified as 18:1 and 10%-11%.The coating amount of outside membrane containing Eudragit■ L30D55 was determined to be 0.8%.The similarity factors(f_(2))of home-made capsule and commercially available product(Harnual■)were above 50 in different dissolution media.DSC studies confirmed that drug and excipients had good compatibility and SEM photographs showed the similarities and differences of coating surface between Harnual■ and self-made pellets before and after dissolution.According to Ritger-Peppas model,the two dosage form had different release mechanism.

Waist Circumference-dependent Peripheral Monocytes Change after Gliclazide Treatment for Chinese Type 2 Diabetic Patients

Gliclazide used for the treatment of type 2 diabetes mellitus（T2DM） stimulates insulin secretion and influences peripheral blood monocytes.The roles of gliclazide in peripheral monocytes of newly diagnosed T2 DM patients were investigated in this study.A total of 105 newly diagnosed T2 DM patients with no history of antihyperglycemic medication were treated with gliclazide-modified release for 16 weeks.The total and differential leukocyte profiles of peripheral blood were measured at baseline and week 16.The peripheral blood monocyte count at week 16 was significantly lower than that at baseline（P=0.019）.Peripheral monocytes level at baseline was positively correlated with waist circumference.After gliclazide treatment,the peripheral monocytes were decreased [（320.09±15.13）×10~6/L vs.（294.19±14.22）×10~6/L] in non-abdominal obesity group,but increased in abdominal obesity group [（344.36±17.24）×10~6/L vs.（351.87±16.93）×10~6/L].Compared with non-abdominal obese patients,abdominal obese patients showed higher Δmonocytes（P=0.046） and Δacute insulin secretion（P=0.049）,but lower ΔHb A1c（P=0.047）.There was significantly positive correlation between Δmonocytes and Δacute insulin secretion（P=0.015）,which disappeared after adjusting for age,waist circumference and dosage at baseline.In conclusion,waist circumference is correlated with peripheral monocyte change after gliclazide treatment in Chinese newly diagnosed T2 DM patients.Peripheral monocytes are decreased in non-abdominal obesity group and increased in abdominal obesity group after gliclazide treatment.

Comparison of gliclazide vs linagliptin on hypoglycemia and cardiovascular events in type 2 diabetes mellitus: A systematic review

BACKGROUND Cardiovascular outcome trials have demonstrated cardiovascular safety of glimepiride(a sulfonylureas) against dipeptidyl peptidase-4 inhibitor linagliptin.Gliclazide(another newer sulfonylureas) has shown similar glycemic efficacy and 50% decreased risk of hypoglycemia compared to glimepiride.AIM Considering the absence of cardiovascular outcome trials for gliclazide, we decided to conduct a systematic review of the literature to assess the cardiovascular(CV) safety by assessing the risk for major adverse CV events and hypoglycemia risk of gliclazide vs linagliptin in patients with type 2 diabetes(T2D).METHODS This systematic review followed the current Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to analyze all the clinical studies published from 2008 that compared the two drugs in patients with T2D with no risk of CV disease(CVD). We included only evidence designated high quality by the Oxford Center for Evidence-based Medicine-Levels of Evidence.RESULTS Eight clinical studies were included in the narrative descriptive analysis(gliclazide: 5 and linagliptin: 3). The CV safety of gliclazide in the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation trial and of linagliptin in the Cardiovascular and Renal Microvascular Outcome Study With Linagliptin(CARMELINA) and CARdiovascular Outcome study of LINAgliptin vs glimepiride in patients with T2D(CAROLINA)trials were excluded from the comparative analysis as these trials demonstrated CV and hypoglycemia benefits in patients at high risk of CVD. However, since these are landmark trials,they were discussed in brief to show the CV benefits and low hypoglycemia risk of gliclazide and linagliptin. We did not find any study comparing gliclazide with linagliptin. Hence, direct comparison of their major adverse CV events and hypoglycemia risk could not be carried out.However, the literature meeting the inclusion criteria showed that both drugs were effective in achieving the desired glycemic control and had low major adverse CV events and hypoglycemia risk in adult patients with no history of CVD.CONCLUSION Gliclazide can be considered an effective and safe glucose-lowering drug in T2D patients with no established CVD but at high risk of CVD due to their T2D status. Future randomized controlled trials comparing gliclazide with linagliptin or dipeptidyl peptidase-4 inhibitors can confirm these findings.

No long-term survival benefit with sustained-release 5-fluorouracil implants in patients with stages Ⅱ and Ⅲ gastric cancer

BACKGROUND The prognosis of gastric cancer in an advanced stage remains poor. The exact efficacy of the use of intraoperative sustained-release chemotherapy with 5-fluorouracil(5-FU) in advanced-stage gastric cancer is still unelucidated.AIM To explore the long-term survival benefit of using sustained-release 5-FU implants in stage Ⅱ and stage Ⅲ gastric cancer patients.METHODS Patients with gastric cancer in a locally advanced stage and who underwent an R0 radical resection between Jan 2014, to Dec 2016, in this single institution were included. Patients with pathological diagnoses other than adenocarcinoma were excluded. All included patients were grouped according to whether intraoperative sustained-release(SR) chemotherapy with 5-FU was used or not(NSR). The primary end-point was 5-year overall survival. Kaplan–Meier method with logrank test was used to analyze the overall survival of patients and Cox analysis was used to analyze prognosis factors of these patients.RESULTS In total, there were 563 patients with gastric cancer with locally advanced stage, who underwent an R0 radical resection. 309 patients were included in the final analysis. 219(70.9%) were men, with an average age of 58.25 years. Furthermore, 56(18.1%) received neoadjuvant chemotherapy, and 191(61.8%) were in TNM stage Ⅲ. In addition, 158 patients received intraoperative sustainedrelease chemotherapy with 5-FU and were included in the SR group, while the other 161 patients were included in the NSR group. The overall complication rate was 12.94% in the whole group and 10.81%, 16.46% in SR and NSR groups, respectively. There were no significant differences between the two groups in overall survival and complication rate(P > 0.05). The multivariate cox analysis indicated that only N Stage and neoadjuvant therapy were independent influencing factors of survival.CONCLUSION Intraoperative sustained-release chemotherapy usage with 5-FU, did not improve the survival of patients who underwent an R0 radical resection in locally advanced stage of gastric cancer.

Preparation and <i>in Vitro</i>Drug Release Evaluation of Once-Daily Metformin Hydrochloride Sustained-Release Tablets

The objective of this study was to develop once-daily metformin hydrochloride sustained-release tablets (MHSRT) and evaluate their in vitro release behavior. MHSRT were prepared by the film coating method. The in vitro drug release rate of MHSRT and the commercial tablets Fortamet? made in the United States of America in water was fitted with zero order kinetic equation, and Ritger-Peppas kinetic equation in 0.1 M HCl and pH 6.8-phosphate buffer, respectively. The similarity factor f2 values of MHSRT in three different dissolution medium were 82, 80 and 74, respectively in comparison with imported Fortamet?, which were all greater than 50. The results of storage-stability showed that MHSRT were stable for at least 6 months under stress condition (40℃ ± 2℃, RH 75% ± 5%). Therefore, in this study, MHSRT were successfully prepared using optimized formulation technologies that meet mass produce. The in vitro release behavior of MHSRT was almost similar to that of imported Fortamet?.

Comparison of the Hypoglycemic, Hypolipidemic and Hepatoprotective Effects of<i>Asparagus racemosus</i>Linn. in Combination with Gliclazide and Pioglitazone on Alloxan-Induced Diabetic Rats

In recent years, the popularity of medicinal plants as a remedy has been increased manifold due to having minimal adverse effects. The current study aimed to compare the hypoglycemic, hypolipidemic and hepatoprotective effects of the ethanolic extract of Asparagus racemosus (EEAR) Linn. alone and combinedly with conventional antidiabetic agents (gliclazide and pioglitazone) in alloxan-induced diabetic rats. Diabetes was induced in male Wister albino rats by the administration of single intra-peritoneal injection of alloxan monohydrate (120 mg/kg b.w.). Effect of oral administration of two different doses of EEAR (200 and 400 mg/kg b.w.), gliclazide (10 mg/kg b.w.) and pioglitazone (10 mg/70kg/b.w.) alone for 2 weeks and a combination of EEAR (200 mg/kg b.w.) with either gliclazide (10 mg/kg b.w.) or pioglitazone (10 mg/70kg/b.w.) for 2 weeks were examined on hypoglycemic activity on 0th, 5th, 10th and 14th day of treatment. After 2 weeks of treatment, hypolipidemic and hepatoprotective effects were estimated by serum biochemical markers such as total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), very low density lipoprotein (VLDL), high density lipoprotein (HDL), serum glutamate oxaloacetate transaminases (SGOT), serum glutamate pyruvate trans-aminases (SGPT) and total protein (TP) with the help of commercially available kits. The survival rate, body weight and organ weight were also measured. Alloxan treatment resulted in persistent hyperglycemia, hyperlipidemia and liver dysfunction in rats. Treatment with EEAR at different doses improved hyperglycemia significantly (p th and 14th day of treatment in a dose-dependent mood when compared to the disease control rats, gliclazide treated rats and pioglitazone treated rats. The combination therapy significantly (p th, 10th and 14th day of treatment as compared to that of disease control rats, gliclazide treated rats and pioglitazone treated rats. Proposed adjunct therapy also markedly (p < 0.001;p < 0.01, p < 0.001) improved serum TG, HDL and LDL level with insignificant change in VLDL and TC level while comparing with groups receiving gliclazide treated rats and pioglitazone treated rats. Administration of different doses of EEAR markedly (p < 0.05, p < 0.01, p < 0.001;p < 0.05, p < 0.01;p < 0.05) reduced the activity of TC, TG, LDL, VLDL and HDL cholesterol levels in a dose-dependent approach with respect to that of gliclazide treated rats and pioglitazone treated rats. The effect of combination therapy significantly (p < 0.001;p < 0.001;p < 0.01, p < 0.001) decreased the SGOT, SGPT and TP hepatic enzyme levels when compared to disease control rats, gliclazide treated rats and pioglitazone treated rats indicated improvement in liver dysfunctions. Administration of different doses of EEAR noticeably (p < 0.05, p < 0.01, p < 0.001;p < 0.05, p < 0.01;p < 0.05, p < 0.01) reduced the liver enzymes level including SGOT, SGPT and TP in a dose-dependent manner as compared to the disease control rats, gliclazide treated rats and pioglitazone treated rats. The maximum survival rate (100%) was observed in rats of combination treated rats. No significant changes in the body weight and organ weight to body weight ratio were observed except the groups that were given combined therapy showed improvement in the liver and pancreas weight. Our study suggests that the EEAR potentiates the activity of gliclazide and pioglitazone in controlling blood glucose levels, modifies the lipid profile and improves in liver dysfunction on alloxan-induced diabetic rats.

Evaluation of Control Effects against Sugarcane Pests：A New Sustained-release and Long-lasting Pesticide and Convenient and Efficient Pesticide Application Technology

[Objective]The paper was to screen a new ideal sustained-release,long-lasting and low-toxic pesticide and convenient and efficient pesticide application technology for controlling Ceratovacuna lanigera and Baliathrips serratus. [Method]2% Imidacloprid GR were selected and applied in the soil for field efficacy trial. [Result] The optimum dosage of 2% imidacloprid GR was 30 kg/hm^2（ active ingredient 600 g）,which can be mixed with fertilizer（ 30 kg pesticide and 40-80 kg fertilizer per hm^2） once combined with sugarcane planting management or big ridging during February and June. The control effects against C. lanigera and B. serratus could be more than 98. 2% and 81. 1%,respectively. The actual yield and sugar content in various pesticide treatments were increased by 33 390 kg/hm^2 and 6. 6% respectively compared to blank control. [Conclusion]2% imidacloprid GR has good control effects on C. lanigera and B. serratus. It is a new pesticide with ideal sustained-release,long-lasting and low-toxin effects against C. lanigera and B. serratus. Therefore,it could be used alternatively with other pesticides,to delay production and development of drug resistance.

Formulation Development and Evaluation of Poorly Water Soluble Gliclazide Tablet Containing Aerosil 380 as Carrier

The core objective of the current work was to improve dissolution rate of poorly water-soluble anti-diabetic drug gliclazide by solid dispersions (SDs) technique using fumed silica particles Aerosil 380 as carrier into compressed tablets. Different FGA-1, FGA-2, FGA-3 (Formulated Gliclazide Aerosil;weight ratio, 1:1) and FPG-1, FPG-2 (Formulated Plain Gliclazide) tablet batches were formulated, prepared, evaluated and characterized. All the findings of pre-compression factors were found to be satisfactory and post-com- pression parameters revealed good mechanical integrity and good uniformity in all formulations. All the formulated tablets satisfied the compendia limits of weight variation, friability and the disintegration time. Among all formulations, FGA-3 was optimized based on in vitro drug release findings, disintegration time, hardness and other quality attributes. The percent of drug release from the formulated FGA tablets containing gliclazide loaded aerosil is about 3 fold higher when compared with the tablets formulated and prepared with plain gliclazide (FPG) and the tested commercial brands in first 60 minutes. There was no significant change noted in the drug content and drug release pattern in the FGA tablets batches when stored in 40℃?and 75% RH for three months. It was thus concluded that SDs formulations of gliclazide could be successfully used to design and develop a solid dosage form of the drug, which would have significant benefits over the existing commercial brands.

Pharmacokinetic Study on Lovastatin Sustained-release Tablet and Sustained-release Capsule in Begal Dogs

This study pharmacokinetically examined the lovastatin sustained-release tablet and sustained-release capsule in Beagle dogs. An reversed-phase HPLC method was established for the determination of lovastatin in Beagle dog plasma. Pharmacokinetic findings were compared among three preparation(lovastatin sustained-release tablet,T p; sustained-release capsule,T J and conventional capsule). Our results showed that the pharmacokinetic parameters in 6 dogs after single-dose oral administration of three perparations were calculated. T max, C max and MRT revealed significant difference (P<0.05). Relative bioavailability was 111.5±16.9 % (T P) and 110.4%±9.6 % (T J). The pharmacokinetic parameters in the 6 dogs after multiple-dose oral administration of three perparations, T max, C max MRT and DF had significant difference (P<0.05); C av , C min and AUC 0-24 h displayed no significant difference (P>0.05). It is concluded that the lovastatin sustained-release tablet and sustained-release capsule are able to maintain a sustained-release for 24 h.

Effects of Sustained-Release Calcium Hydroxide and Sustained-Release Hydrochloric Acid on Nutrient Di-gestion and Absorption of Rabbits

Rabbits with the body weight of （2.0 ± 0.5 ） kg were chosen, to study the effects of sustained-release calcium hydroxide and sustained-release hydro- chloric acid on nutrient digestion and absorption of rabbits. The results showed that sustained-release calcium hydroxide promoted digestion and absorption of nutri- ents, especially calcium and crude protein. The digestibility of calcium and crude protein was increased from 89.8% and 93.8% to 41.0% and 65.2%, respec- tively. Sustained-release hydrochloric acid was adverse to digestion and absorption of nutrients, especially calcium and crude protein. The digestibility of calcium and crude protein were decreased from 55.5% and 84.9% to 28.4% and 68.7%, respectively. The promotion effects of sustained-release hydrochloride on diges- tion lasted for 3 -4 d. Therefore, sustained-release calcium hydroxide promoted digestion and absorption of calcium and protein, while digestion and absorption of fat remained at a high level no matter what the condition was. Consequently, increasing the intake of fat would cause over nutrition. However, taking sustained-re- lease hydrochloric acid would reduce nutrient digestion and absorption.

Preparation and evaluation of sustained-release azithromycin tablets in vitro and in vivo

The objective of this study was to prepare azithromycin(AZI)sustained-release products in order to allow for a high dose to be administered,reduce gastrointestinal side-effects and increase the compliance of patients.AZI sustained-release tablets with different release performance(F-I:T_(100%)=3 h and F-II:T_(100%)=8 h in pH 6.0 phosphate buffer)were successfully prepared by wet granulation.The in vitro release rate and drug release mechanism were studied.The release rate of F-Iwas affected by dissolutionmedia with different pH,but not for F-II.HixsoneCrowellmodel was the best regression fitting model for F-I and F-II.Additionally,F-I and F-II both belonged to non-Fick diffusion.Oral pharmacokinetics of the two tablets and one AZI dispersible tablet as reference were studied in six healthy beagle dogs after oral administration.Compared with the reference,the C_(max) of F-I and F-II were decreased,and the T_(max) were prolonged,in that case which meet the requirement of sustained-release tablets.The relative bioavailability of F-I and F-II were 79.12%and 64.09%.T-test ofAUC_(0-144),and AUC_(0-∞) for F-I and F-II indicated there was no significant difference between F-I and F-II.These mean that the extended release rate did not induce different pharmacokinetics in vivo.