OBJECTIVE:To optimize the formulation of azithromycin sustained-release vaginal suppository(ASVS).METHODS:The ASVS was prepared using S-40 as suppository base,HPMC as sustained-release material and glycerine as humectant.The formulation of ASVS was optimized by orthogonal design with accumulated release percentage and hardness as indexes and the amount of 8% HPMC and glycerol as factors;meanwhile,a verification test and the fitting of in vitro drug release model were performed.RESULTS:The optimized formulation ASVS was as follows:azithromycin 6 g,8% HPMC 23.52 g,glycerol 29.40 g,ethanol absolute 3 g,ethylparaben 0.59 g,and S-40 294 g.Three batches of suppositories prepared under the optimized formulation reached a mean content of 99.5%,with hardness up to the standard,showing good reproducibility and homogenicity in drug release in vitro.The accumulative release rates of all samples were greater than 98% at 180 min,and the release dynamics in vitro were in line with Higuchi equations.CONCLUSION:The optimized ASVS is feasible in formulation,stable and reproducible in preparation technology and up to the standard for sustained-release preparation.

The multiple-step cleavage of amyloid precursor protein (APP) generates amyloid-β peptides (Aβ), highly toxic molecules causing Alzheimer's disease (AD). The nonspecific cleavage between the transmembrane region of APP (APPTM) and γ-secretase is the key step of Aβ generation. Reconstituting APPTM under physiologically-relevant conditions is crucial to investigate how it interacts with γ-secretase and for future AD drug discovery. Although producing recombinant APPTM was reported before, the large scale purification was hindered by the use of biological protease in the presence of membrane protein. Here, we expressed recombinant APPTM in Escherichia coli using the pMM-LR6 vector and recovered the fusion protein from inclusion bodies. By combining Ni-NTA chromatography, cyanogen bromide cleavage, and reverse phase high performance liquid chromatography (RP-HPLC), isotopically-labeled APPTM was obtained in high yield and high purity. The reconstitution of APPTM into dodecylphosphocholine (DPC) micelle generated mono dispersed 2D ¹⁵N-¹H HSQC spectra in high quality. We successfully established an efficient and reliable method for the expression, purification and reconstruction of APPTM, which may facilitate future investigation of APPTM and its complex in more native like membrane mimetics such as bicelle and nanodiscs.
Humans ; Amyloid beta-Protein Precursor/chemistry* ; Micelles ; Amyloid Precursor Protein Secretases/metabolism* ; Magnetic Resonance Spectroscopy ; Recombinant Proteins

G protein-coupled receptors (GPCRs) are involved in all human physiological systems where they are responsible for transducing extracellular signals into cells. GPCRs signal in response to a diverse array of stimuli including light, hormones, and lipids, where these signals affect downstream cascades to impact both health and disease states. Yet, despite their importance as therapeutic targets, detailed molecular structures of only 30 GPCRs have been determined to date. A key challenge to their structure determination is adequate protein expression. Here we report the quantification of protein expression in an insect cell expression system for all 826 human GPCRs using two different fusion constructs. Expression characteristics are analyzed in aggregate and among each of the five distinct subfamilies. These data can be used to identify trends related to GPCR expression between different fusion constructs and between different GPCR families, and to prioritize lead candidates for future structure determination feasibility.
Animals ; Computational Biology ; Crystallography, X-Ray ; Gene Expression ; Humans ; Plasmids ; genetics ; metabolism ; Protein Domains ; Receptors, Adrenergic, beta-1 ; Receptors, G-Protein-Coupled ; classification ; genetics ; metabolism ; Receptors, Odorant ; metabolism ; Receptors, Purinergic P1 ; genetics ; metabolism ; Sf9 Cells ; Spodoptera