苦参碱直肠原位温敏凝胶的制备及性能评价

目的优选得到具有温敏性和直肠滞留黏附性的苦参碱原位温敏凝胶。方法通过冷法制备,以胶凝温度为指标,采用星点设计-效应面法(CCD-RSM),对泊洛沙姆407(P407)、泊洛沙姆188(P188)以及羧甲基纤维素钠(CMC-Na)的用量进行优选,采用质构仪测定制剂的凝胶强度、黏附力,通过大鼠直肠给药考察其直肠滞留情况,并以改良桨法考察体外释放度。结果确定的苦参碱原位温敏凝胶最优处方为苦参碱2%、CMC-Na 1.0%、P188 1.3%、P407 16.5%、苯扎溴铵0.02%。该处方凝胶在大鼠直肠给药后不会出现泄漏,且能在体内滞留6 h以上,其体外释放符合Weibull模型。结论优选得到符合直肠给药需求的苦参碱原位温敏凝胶。     

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??OBJECTIVE To prepare the tulobuterol crystal reservoir patch, and to evaluate morphology, stability and crystallization factors of the crystal in the patch, adhesive force, dissolution, transdermal properties in vitro and the pharmacokinetics in rabbits. METHODS The transdermal patch was prepared on the basis of drug recrystallization and characterized by morphology, stability and crystallization factors using microscope and adhesive force using initial adhesion tester, adhesion tester and peel tester. The dissolution and transdermal properties were evaluated by using the dissolution tester and transdermal tester. In addition, pharmacokinetics was studied using New Zealand rabbits as experimental animals. RESULTS The drug crystals were evenly distributed in the form of filaments, which had average width of (4.4??1.8)??m and kept stable at 2-40 ??. The crystallization in patches is affected by tulobuterol supersaturation and temperature. The adhesive force of patch was suitable and its dissolution matched standard which can be fitted by the Higuchi equation. In the diffusion cell in vitro, the drug penetrated through the skin in a Zero-order kinetic equation, and the cumulative penetration percentage and skin retention concentration were 92.04% and 10.36 ??g??cm^-2 with in 24 h. The pharmaceutic parameters showed that the tulobuterol blood concentration can be maintained within 24 h, whose t_max and ??_max were (6.67??3.06)h and (3.08??1.32) ng??mL^-1, respectively. CONCLUSION The tulobuterol crystal reservoir patch can be established by control of recrystallization conditions. The patch has good adhesive properties and sustained release characteristics in vitro and in vivo, which has the practical significance for further study.     

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??OBJECTIVE To prepare ion-sensitive ophthalmic in situ gel containing bendazac lysine (BDZL-ISG) and preliminarily study its rheological behavior, in vitro drug release, corneal permeation, and pharmacokinetics in rabbit aqueous humor. METHODS Single factor investigation was carried out to optimize the formulation, taking viscosity and gelling capacity as evaluation indices. Using aqueous solution or eye drops as control, the in vitro release of the formulation was evaluated by dialysis membrane method. Then, the corneal permeation experiment of the optimum formulation was carried out with Franz diffusion cell. The pharmacokinetics of BDZL-ISG in rabbit aqueous humor was preliminarily studied by microdialysis. RESULTS Compared with the control group, the optimum formulation had shear thinning behavior and significant sustained release effect. There was no significant difference in the corneal permeation between the two groups. The RESULTS of pharmacokinetic study showed that ??_max (13.25 ??g??L^-1) and AUC_0-t of BZDL-ISG were 2.38 and 2.2 times higher than those of BDZL eye drops respectively, which suggested that the ocular bioavailability of BDZL was greatly enhanced by the optimum in situ gel formulation. CONCLUSION With significant sustained release effect, the ion-sensitive ophthalmic in situ gel will become a promising alterative formulation for bendazac lysine for treatment of cataracts.     

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??OBJECTIVE To prepare lappaconitine(LA)-loaded chitosan/ sodium ??-glycerophosphate(CS/??-GP) thermosensitive hydrogels and investigate its phase transition mechanism of gel formation process and release properties in vitro. METHODS The injectable CS/??-GP thermosensitive hydrogels were prepared with biodegradable CS as carrier material and ??-GP as coagulation accelerator. The release behavior in vitro was studied by dynamic dialysis, and the phase transition mechanism of gel formation process was further investigated by rheological method. RESULTS The optimized process condition was as follows:the concentration of ??-GP and CS was 560 and 22 mg??mL^-1, respectively, CS was dissolved by 0.1 mol??L^-1 HOAc, and the valume ratio of CS to ??-GP was 8.75??1.25(V/V), the gelation time of CS/??-GP thermosensitive hydrogels with volume ratio of 8.75??1.25(V/V) at 37 ?? was 5 min 38 s. The in vitro release study showed that these injectable CS/??-GP thermosensitive hydrogels had sustained release effect for LA, and the release behavior could be well described by the Higuchi model and Korsmeyer-Peppas model. The mechanism of LA releasing from CS/??-GP thermosensitive hydrogels was attributed to drug dissolution and diffusion. Rheological studies showed that the CS/??-GP thermosensitive hydrogels belonged to thixotropic system and exhibited non-Newtonian and shear-thinning fluid behavior as well as ??solid-like?? gelatin behavior. CONCLUSION LA-Loaded CS/??-GP injectable thermosensitive hydrogels with good elasticity and gel strength properties are prepared successfully, and they show sustained release effect of LA in vitro.     

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??OBJECTIVE To investigate the in-vitro release behavior of venetoclax preparations, the pharmacokinetic processes and the correlations between in-vitro release and in-vivo absorption of venetoclax in Beagle dogs. METHODS The dissolution curves of venetoclax preparations in different dissolution media were studied. HPLC method was established for the determination of venetoclax in Beagle dogs, and the pharmacokinetics were studied for commercial venetoclax tablets in Beagle dogs under fed and fasted states.The IVIVC study was carried out by linear regression of cumulative in-vitro drug release and in-vivo absorption accumulation percentage data. RESULTS The in-vitro release behavior among venetoclax formulation in 4 dissolution media were significant difference. The simple, accurate and rapid analysis method for venetoclax blood samples was established. The fed group and the fasted group AUC_0???? were (32.38??5.87) and (27.70??6.32) mg??h??L^-1, the concentration of peak were (4.04??0.78) and (3.72 ??0.69) ??g??mL^-1, the peak time were (6.01??1.04) and (4.27??0.92) h, respectively, and there was obvious difference (P<0.05) in AUC_0???? and the peak time between two group. Percentage of in-vivo absorption was in good agreement with in-vitro release in pH 6.8 0.2%SDS media. CONCLUSION The study shows that food could improve the bioavailability of venetoclax formulation; 0.2%SDS pH 6.8 media (paddle, 75 r??min^-1) is the in-vivo release of venetoclax associated with the in-vitro release condition.     

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??OBJECTIVE To prepare and optimize meloxicam nanosuspensions fast dissolving sublingual films (MLX-NS-FDSFs) and to evaluate its in vitro dissolution characteristics. METHODS Meloxicam nanosuspensions (MLX-NS) were prepared by pH-dependent dissolving-precipitating/high speed shearing method and then transformed into fast dissolving sublingual films (FDSFs). The formulations of MLX-NS-FDSFs were optimized by employing Box-Behnken design-response surface methodology with the amount of HPMC-E30, PEG-400 and MLX-NS as investigation factors, and particle size of reconstituted nanoparticles from MLX-NS-FDSFs, disintegration time and stretch length as indexes. The morphology, content uniformity and in vitro dissolution of the optimal formulation were also evaluated. RESULTS The MLX-NS-FDSFs prepared by optimized formulation (35 mg??mL^-1 HPMC-E30, 40 mg??mL^-1 PEG-400, 10 mL MLX-NS) could fast disintegrate in (26.08??1.76) s, the tensile length was (1.51??0.13) mm, and the particle size of reconstituted nanoparticles from MLX-NS-FDSFs was (186.4??6.3) nm. There was a little deviation between the theoretically predicted value and the measured value. It showed that this model had a good prediction. Morphological analysis showed that well-dispersed MLX nanoparticles embedded in MLX-NS-FDSFs. The conformity of drug content was up to standard. MLX could be released in vitro as much as (91.75??8.05)% within five minutes. CONCLUSION Using Box-Behnken design and response surface method to optimize MLX-NS-FDSFs is effective and feasible. MLX-NS-FDSFs can significantly increase the cumulative dissolution of MLX.     

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??In situ gel is liquid upon instillation and undergo phase transition under physiological conditions to form visco-elastic gel with dual advantages of liquid and gel.Ordinary eye drops exist a problem of short residence time with low bioavailability. In recent years, an impressive number of novel in situ gel systems have been reported for ocular drug delivery to increase bioavailability with the extension of corneal residence time. In this article, the classification and application about in situ gel for ocular drug delivery are reviewed, then the study status and the key technical problem of the in situ ophthalmic gel in detail are described. In addition, the future advancement of this field is also discussed.     

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??OBJECTIVE To enhance dissolution rate of silymarin (SM) by forming SM nanoparticles (SM-NA) with supercritical anti-solvent (SAS) method. MOTHODS Single-factor test was employed to investigate the influencing factors of particle size and yield of SM-NA, such as pressure, temperature, flow rate, and concentration of the solution. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) were used to determine the state of SM-NA. The dissolution characteristics in vitro were investigated with 0.3% SDS aqueous solution as the solvent and compared with the SM powder. RESULTS Taking size distribution as well as yield of SM-NA as the evaluation indexes, the optimal prepration parameters were selected as followings:pressure 15 MPa, temperature 35 ??, flow rate 1.5 mL??min^-1, concentration 100 mg??mL^-1. The XRD and DSC of SM-NA described the decrease of SM in crystallinity, and it was transformed mostly with the amorphous state, compared with the SM powder. The accumalte release rate of SM-NA achieved 80% within 10 min, markedly higher than that of the SM powder and its commercial preparation. CONCLUSION The SM-NA prepared by SAS has remarkablly smaller particle size thus can greatly improve the in vitro release of SM.
     

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??OBJECTIVE To examine the in vitro release profile and in vivo retention of estradiol vaginal thermosensitive gel (E2-VTG).METHODS E2-VTISG was prepared by cold dissolving method.The dynamic membrane dialysis method and HPLC-fluorometric method were used to determine the in vitro release characteristic of the estradiol vaginal thermosensitive gel.CRi Maestro was applied to evaluate the retention of E2-VTG in ICR mice with IR820 as the fluorescent marker. RESULTS Estradiol could be released slowly from the thermosensitive gel and the release profile was fitted with Higuchi equation. It was speculated that estradiol was mainly released through diffusion.NIR imaging and fluorescence quantitative analysis showed that thermosensitive gel could reside in vagina for at least 8 h. CONCLUSION Estradiol thermosensitive gel can prolong the drug residence time in vagina and sustain the drug release rate.