ABSTRACT
In this study, fluvoxamine maleate sustained-release pellet system tablets were prepared and were used to evaluate their release behaviors in vitro. Fluvoxamine maleate pellets were prepared using centrifugal-spherization method and coated by fluidized bed as bottom-spray. The multi-unit sustained-release pellets and appropriate excipients for prescription volumes were mixed uniformly and then compressed to tablets. Screening and determining the optimal formulation of drug loaded pellets through L8 (24) Taguchi experiment. Using Minitab software to design a DOE experiment with 24 partial factors, including material temperature, fan speed, atomization pressure, and spray rate to optimize the bottom spray coating process. Taking monostearate glycerol ester with a particle size of 24-40 mesh as the main diluent for tableting to relieve the delamination phenomenon between pellets and excipients during tablet pressing and reduce mechanical damage to the coating film. By examining the powder fluidity indexes such as angle of repose, bulk density, tapped density, and Hausner ratio of mixed particles, it was found that the flowability and compressibility are good and suitable for direct compression. Evaluate the basic properties of the sustained-release tablets, investigate the in vitro release behavior and study the release mechanism. The results of in vitro release test showed that the self-made sustained-release tablets could disintegrate into independent pellet units in phosphate buffer at pH 6.8 and release slowly within 24 h, which conformed to the first-order drug release model. The fluvoxamine maleate sustained-release pellet system tablets meet the requirements of preparation design and has a great commercial prospect.
ABSTRACT
UiO-66 (University of Oslo 66) is a kind of promising material that can improve the release and bioavailability of poorly water-soluble bioactive compounds of traditional Chinese medicine. However, the loading of quercetin in raw UiO-66 was not ideal. In this study, UiO-66-BH (UiO-66-blend-heating) was obtained by heating UiO-66 and KOH solution following blended them. UiO-66-BH maintained the outline of octahedral structure of UiO-66 but with obvious rough and uneven pores on the surface. UiO-66-BH had good adsorption of quercetin with saturation adsorption was 138.92 mg·g-1, the adsorption process belonged to single molecular layer adsorption and was controlled by chemisorption. UiO-66-BH can control the release of quercetin in simulated gastrointestinal fluid, and the drug concentration was significantly higher than that of free quercetin after long-term release (36% vs 9%). Compared with quercetin, the ABTS (2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt) radical scavenging activity of UiO-66-BH@quercetin drug delivery system decreased, while the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity remained almost unchanged. The drug delivery system showed a strong antioxidant effect similar to quercetin. The findings indicated that UiO-66-BH could control release of quercetin and was expected to be used as a drug carrier material for some insoluble active components of traditional Chinese medicine such as quercetin.
ABSTRACT
As a depot drug delivery system, injectable polylactide-polyglycolide (PLGA) sustained-release microspheres have been successfully used to treat many diseases since the first microsphere product Lupron depot was approved for marketing in the United States in 1989. It has the ability of long-term release in the body for several days to several months, which can not only reduce the times of administration, but also reduce the drug blood concentration fluctuations, significantly improve the safety and patient compliance. In vitro-in vivo correlation (IVIVC) makes the development of microspheres more possible. It can describe the dynamic information of drug release in vivo through the in vitro release behavior of microspheres, and can reduce the workload of each stage and shorten the time span while characterizing the performance of microspheres. IVIVC can provide guidance or support for drug development, production changes, supervision and management. This article summarizes the release mechanism of injectable PLGA sustained-release microspheres, common measurement methods and theories of in vitro and in vivo release. And we also focus on the establishment and application of IVIVC, especially A level IVIVC in the field of microsphere preparations, to provide a reference for further study on in vitro-in vivo correlation of microspheres.
ABSTRACT
The objective of this paper was to establish a level A in vitro-in vivo correlation (IVIVC) for goserelin acetate extended release microspheres for injection. Three kinds of goserelin acetate microspheres with different release rates were prepared and the critical physicochemical properties, such as drug loading, particle size, glass transition temperature and morphology were characterized. In vitro dissolution test of the prepared goserelin acetate microspheres was performed using sample-and-separate method at 45 ℃ in 5% (v/v) methanol. The morphology of the microspheres and the molecular weight of poly (lactic-co-glycolic acid) (PLGA) of the prepared goserelin acetate microspheres were investigated to research the release mechanism of microspheres. The plasma concentration of goserelin was detected after intramuscular injection of goserelin acetate microspheres to SD rats, and correlated with the in vitro release profiles after processing by percent AUC method. The pharmacokinetic experimental protocol of goserelin acetate microspheres for injection in SD rats was approved by the Animal Ethics Committee of Shandong Luye Pharmaceutical Co., Ltd. The results indicated that the developed sample and separate method was able to detect differences in the release characteristics of the prepared goserelin acetate microspheres, and the in vitro-in vivo correlation of goserelin acetate microspheres was excellent (r > 0.98) and had good predictive ability in SD rats.