ABSTRACT
Objective To prepare TOGA-X4 microparticles with uniform size and good rehydration property and to obtain the stable and reliable preparation process, and evaluate the in vitro release characteristics. Methods With the average particle size, polydispersity index and rehydration as indexes, optimizing the process of antitumor active substance TOGA-X4 microparticles by stainless steel rapid film emulsification method through single factor investigation to investigate the factors influencing the size and dispersion of the drug microparticles and observe the morphology of the particles by scanning electron microscopy. With the cumulative release degree of TOGA-X4 as index, direct drug release method was adopted to determine the cumulative release rate of TOGA-X4 and the size of TOGA-X4 microparticles. The curve of in vitro drug release was fitted with different release model to estimate the in vitro release characteristics of TOGA-X4 raw powders and TOGA-X4 microparticles. Results The optimized preparation technology contained TOGA-X4 mass concentration of 5 mg/mL in oil phase, PVA mass concentration of 30 mg/mL in for aqueous phase, the ratio of oil to water was 1:1, transmembrane pressure at 0.4 MPa, sucrose aqueous solution of 50 mg/mL as freeze-drying protective agent, curing temperature at 70 ℃; Compared with other in vitro release models, the logistic equation was the fittest model to TOGA-X4 microparticles, zero order equation was the fittest model to TOGA-X4. Conclusion The preparation of microparticles by stainless steel rapid film emulsification is simple, stable and reliable, which can improve the dissolution rate of insoluble drugs and has advantages in the preparation of microparticles of poorly water-soluble drugs.
ABSTRACT
Background: An adaptive mechanism in plant roots is initiated in the event of nitrogen and potassium deficiency, and it facilitates the active uptake of these elements in order to ensure plant growth and survival in stress conditions. Signaling and transduction of signals in response to changing nitrogen and potassium concentrations is a complex process, affected by interactions between various gene expression products, and often subjected to modifications. Results: In order to identify genotypic differences between phenotypes of two populations of recombinant inbred rye lines (153/79-1 x Ot1-3 and Ot0-6 x Ot1-3) in response to nutrition stress caused by nitrogen and potassium deficiency at the seedling stage, bulk segregant analysis was utilized. Identification of genotypic differences between and within pooled DNA samples involved 424 RAPD, 120 ISSR primers and 50 combinations of R-ISSR. Identified markers were sequenced and converted to SCAR, attributing to them unique ESTs annotations, and chromosomal ones to selected localizations. Significant relationships with the examined trait were described for nine and eight RAPD markers, four and five ISSR, one and three R-ISSR markers for population 153/79-1 x Ot1-3 and Ot0-6 x Ot1-3, respectively. Sequences identified for the rye genome were characterized by a uniqueness and a similarity to the sequence of aquaporin PIP1, a gene encoding protein related to the function of the transcription factor in plant response to iron deficiency and the putative ethylene-responsive transcription factor, cytosolic acetyl-CoA carboxylase, HvHKT1 transporter, as well as HCBT proteins. Conclusion: Identified molecular markers differentiating rye genotypes of extreme response of root system on nitrogen and potassium deficiency play a significant role in systemic plant response to stress, including stress caused by nitrogen and potassium deficiency. They may constitute a system facilitating selection, and together with the material they are described in, they may be a starting point for research on mechanisms of sensing and transduction of signal across the plant.