[Studies on in vitro release kinetics of gentamicin sulfate polybutylcyanoacrylate nanoparticles].

The in vitro release characteristics of gentamicin sulfate polybutylcyanoacrylate nanoparticles were studied using a dialysis system comprising dialysis bag and receptor chamber. The whole apparatus was placed in a water bath shaker thermostated at 37 degrees C, and shaken at 50 cpm. The concentration of gentamicin in the receptor chamber was periodically determined by first derivative spectrometry. The results showed that the in vitro release of gentamicin sulfate from polybutylcyanoacrylate nanoparticles is characteristically biphasic, with an initial fast release (the burst effect), followed by a much slower release. These release profiles can be well modelled using a biexponential function. The related parameters of release kinetics have been calculated according to the biexponential function, and some factors that may affect the release characteristics were studied.

[Study on sodium norcantharidate albumin microspheres].

In this paper sodium norcantharidate (Na2NC) was chosen as model drug and sodium norcantharidate albumin microspheres (Na2NC AM) was prepared by an optimal procedure. The embedding nature, appearance, morphology, size and size distribution, release characteristics in vitro, freeze-drying, 60Co radiosterilization and stability of Na2NC AM were tested. The results showed that the mean size was 0.43 +/- 0.12 micron, embedding concentration was 20.34-26.75 micrograms/mg, embedding ratio was 21.9-26.4%, release characteristics in vitro was in accord with Higuchi equation. Freeze-drying and 60Co radiosterilization showed no influence on Na2NC AM. The stability of Na2NC AM was good after 3 months storage.

[Study on pharmacokinetics of mitoxantrone polycyanoacrylate nanoparticles freeze-dried injection by HPLC column switching technique].

The drug concentration--time curves of mitoxantrone polycyanoacrylate nanoparticles freeze-dried injection (DHAQ-PBCA-NP-FDIn) and mitoxantrone solution injection (DHAQ-SIn) in rabbit blood were determined by HPLC column switching technique, and the difference between the DHAQ-PBCA-NP-FDIn and DHAQ-SIn in vivo was observed. The pharmacokinetic parameters of DHAQ-PBCA-NP-FDIn and DHAQ-SIn were presented by statistical moment. The results showed that the MRT and T1/2 of DHAQ-PBCA-NP-FDIn were 2.15 times longer than that of DHAQ-SIn, and the Vss was 4.81 times bigger than that of DHAQ-SIn. This indicates that DHAQ-PBCA-NP-FDIn has targeting and prolonging effect on the action in vivo.

[Study on mitoxantrone polycyanoacrylate nanospheres].

The mitoxantrone polybutylcyanoacrylate nanosparticles (DHAQ-PBCA-NP) were prepared by emulsion polymerization method. The surface charge, drug loading, morphology, size and size distribution, release characteristics in vitro, stability and distribution in animals of DHAQ-PBCA-NP were studied. The results showed that the mean size was d(av) = 55.23 nm, drug loading was 46.77%, embedding ratio was 84.89%. The surface carried negative charge and the release characteristics in vitro was in accord with two phases kinetics law. The colloidal solution of DHAQ-PBCA-NP can undergo boiling for 30 min sterilization. The radioactivity concentrated mainly in liver after iv 3H-DHAQ-PBCA-NP. The radioactivity in liver tumor was higher than that in the liver tissue. DHAQ-PBCA-NP was observed in parenchymal cell 15 min after iv DHAQ-PBCA-NS. This preparation seems to have important value for increasing the anti-liver tumor effect and decreasing the toxicity of DHAQ.

[Study on the mitoxantrone ethylcellulose microspheres for liver artery embolization].

In this paper, orthogonal test was used to optimize the preparation conditions and technique of mitoxantrone ethylcellulose microspheres (DHAQ-EC-MS) for liver embolization. The dynamic osmosis method was used to study the drug release characteristics of DHAQ-EC-MS. DHAQ-EC-MS suspension for clinical liver artery embolization was prepared. The result showed that the DHAQ-EC-MS is regular in its morphology with a mean diameter of 110.24 +/- 38.19 microns. The drug loading was 12.5% and embedding ratio was 55.6%. The release characteristics was in accord with single exponential model. The drug release equation is lg(Yinfinity - Y) = -0.116t - 1.198 x 10(-3) (gamma = 0.9992, t50 = 2.6 h). The DHAQ-EC-MS was shown to be physically and chemically stable and its suspension is suitable for clinical use. Experiments in dogs indicate that drug concentration of DHAQ-EC-MS in hepatic vein blood was higher than DHAQ solution, and the MRT0-72 was 2.45 times higher than DHAQ solution.

[Increase of gentamicin uptake in cultured mouse peritoneal macrophage and rat hepatocytes when used in the form of nanoparticles].

The polybutylcyanoacrylate nanoparticles of 3H-labeled gentamicin were prepared in order to investigate the possibility of gentamicin nanoparticles as an intracellular drug delivery system for intracellular chemotherapy. The 3H-labeled gentamicin nanoparticles were incubated with mouse peritoneal macrophage (MPM) or rat hepatocytes (RH) for some period, then the cells were separated from the nanoparticles, and finally the radioactivity (cpm) of 3H in the cells were measured by a liquid scintillation counter. By comparison with the solution of 3H-labeled gentamicin, a 6.34 times increase of cpm value in MPM after 30 min incubation, and 27.74, 9.03 and 8.36 times increase of MPM values in RH after 1, 12, and 24 h incubation respectively, were observed by binding gentamicin with polybutylcyanoacrylate nanoparticles. The particle size, surfactant coating, stabilizer and the gentamicin concentration were found to have some effect on the uptake of nanoparticles by two kinds of cells. This study provided a basis for the screening of intracellular drug delivery system.

[Study on albumin microspheres as drug carrier for liver targeting].

In this paper 6 factors and 12 levels of each variable were selected by Uniform Design Method and computer for preparing albumin microspheres with emulsion-chemical cross-linking. An optimal procedure for preparing albumin microspheres was established and the mean diameter of albumin microspheres is 0.41-0.47 micron. Albumin was labelled with 125I-isotope and 125I-albumin microspheres were prepared according to the optimal procedure. The suspension of 125I-albumin microspheres with 0.1% Tween-80 saline was injected via mice tail vein. The animals were sequentially killed and the radioactivity of blood, spleen, liver, kidney, stomach, heart, lung, thyroid and brain were measured. The results showed that albumin microspheres were accumulated mainly in the liver, about 68% of the injected dose at the peak concentration. The pharmacokinetics of albumin microspheres in liver was also studied and two-compartmental model can be used to describe the regulation.

[Feasibility assessment of skin permeation for the local anesthetic lidocaine].

In this paper, the feasibility of skin permeation for lidocaine and pressure sensitive adhesive (PSA) tape formulation containing lidocaine for skin local anesthetic were assessed. Firstly, in vitro skin permeation of the molecular and ionic forms of lidocaine from water and silicone fluid suspensions was measured using a side-by-side two diffusion cells and excised hairless rat skin. Secondly, PSA tape containing lidocaine was prepared by a general casting method using styrene-isoprene-styrene block copolymer. The in vitro release and skin permeation were evaluated and compared with that of Japan marketed xylocaine jelly. The effect of lidocaine concentration on the steady-state flux of skin permeation from 10% to 60% lidocaine PSA tapes was also evaluated.

[Studies on cisplatinum albumin microspheres for lung targeting].

An optimum procedure was established by orthogonal test for preparing cisplatinum albumin microspheres (CDDP-BSA-MS) with emulsion-chemical cross-linking. The quality, stability, distribution in vivo, kinetic characteristics and safety of the albumin microspheres were studied. The results showed that the surface was regular, the mean size was 13.13 +/- 3.55 microns, embedding ratio was 21.62% and the release characteristics in vitro were in accord with "biphase kinetics equation". The stability of the albumin microspheres was good after three months storage. The microspheres accumulated almost entirely in the lung 15 minutes after intravenous injection to mice. The total amount in the lung was about 97% of the injected dose at the peak concentration. Two-compartmental model can be used to describe the regulation of the pharmacokinetics of albumin microspheres in lung. Observation of the lung slice of mice showed no pathological damage.

[Photodecomposition of artificial calculus bovis].

Artificial calculus bovis (ACB) is widely used in dispensing Chinese Traditional Patent Medicine as a substitute for Calculus bovis. Photodecomposition rule of ACB sample irradiated with three different light sources was studied by diffuse reflectance spectrophotometry (DRS) in this paper. The results show that, the photodecomposition rate curves of the ACB sample irradiated by all three light sources are composed of two straight lines of different slopes, indicating that they are of two-step apparent first order reaction, the apparent photodecomposition constants in the first steps are about twice as high as those in the second steps. The ACB sample has the fastest photodecomposition rate when irradiated with the UV mercury-arc lamp and the second with the fluorescent mercury-arc lamp and slowest with the iodine-tungsten lamp. In these three light sources apparent photodecomposition constants of ACB sample are respectively: K1, 2.7629 x 10(-5), 4.4132 x 10(-6); k2, 1.2176 x 10(-5), 2.0684 x 10(-6), 1.4357 x 10(-6) (lx-1.h-1). The apparent constants are independent of the product of the radiation intensity and the irradiation time, but the irradiation time is in inverse ratio of the radiation intensity to get the same proportion of the sample photodecomposition. The fading time of the ACB sample under different radiation intensity can be predicted with the kinetic equations reported. The fading time of ACB sample if directly exposed to light in bright room is 1.6 days.(ABSTRACT TRUNCATED AT 250 WORDS)

[Study on cisplatin albumin microspheres for neck external artery embolization].

In this paper the technique of emulsion chemical-crosslinking was used to prepare cisplatin albumin microsphere for jaw squamous cancer by neck external artery embolization. It was yellow powder with yield 80 +/- 5%, mean size 56.3 microns, cisplatin concentration 14.02-14.20%, loading rate 97.08-97.95%. The release characteristics in vitro, sterilization, stability and recipe of disperse solvent of cisplatin albumin microsphere were investigated. Animal test showed that cisplatin albumin microsphere may plug the branches of neck external artery well and remain in local tissue.

[The antihepatoma effect of lyophilized aclacinomycin A polyisobutylcyanoacrylate nanoparticles in vitro and in vivo].

This paper reports the results of experiments on the antihepatoma effects of live targeted drug delivery system--lyophilized aclacinomycin A polyisobutylcyanoacrylate nanoparticle (ACM-IBC-NP) in vitro and in vivo. The median inhibition concentration were found to be 0.28 micrograms.ml-1 and 0.34 micrograms.ml-1 of lyophilized ACM-IBC-NP and ACM respectively in vitro. The inhibition ratio of colony formation were found to be 99% and 88% of lyophilized ACM-IBC-NP and ACM respectively in vitro. The antihepatoma activity was shown to be significantly concentration dependent. The results showed that lyophilized ACM-IBC-NP and ACM possess strong cytotoxicity on human hepatoma cell 7703, and the cytotoxicity was not significantly different between lyophilized ACM-IBC-NP and ACM in vitro. The model of orthotopic transplantation of human hepatoma in nude mice were used for evaluation of the activity of lyophilized ACM-IBC-NP against hepatoma. The tumor inhibition rate were found to be 86.84% for lyophilized ACM-IBC-NP and 46.69% for ACM. The cell proliferative activity of hepatoma were found to be 20.83% by lyophilized ACM-IBC-NP and 72.50% by ACM. All the results indicate that lyophilized ACM-IBC-NP and ACM have clinical application potential and the antihepatoma activity of lyophilized ACM-IBC-NP was obviously higher than that of ACM.

[Determination of the contents of bufadienolide and borneol in liushen pills].

The contents of bufadienolide and borneol in 01 and 02 Liushen Pills were determined by second-derivative spectrophotometry and gas chromatography respectively. The average recover of bufadienolide by SDS was 100.12% (n = 6, RSD = 1.44%) and of borneol by GC 97.68% (n = 4, RSD = 1.32%).

[Application of beta-cyclodextrin inclusion complex in liushen pills].

01 Liushen Pills (prepared by beta-CD inclusion complex) and 02 Liushen Pills (prepared according to the normal way) were compared by quality inspection, stability test, pharmacological experiments of irritative effects and dissolution test. The results indicated that 01 Liushen Pills were superior to 02 Liushen Pills.

[Optimization of the preparing process for sinitang drop pills by orthogonal test].

The preparing process for Sinitang drop pills was optimized by orthogonal test. The results from nine experiments were subjected with three indexes to objective analysis and variance analysis, and an optimum preparing process for Sinitang drop pills was sieved out. The quality of the drop pills prepared in this way was examined to be up to the standard.