Optimization of S-Nitrosocaptopril Monohydrate Storage Conditions Based on Response Surface Method

Abstract

From unstable crystals to relatively stable monohydrate crystals, many researchers have been working on S-nitrosocaptopril for more than two decades. S-nitrosocaptopril monohydrate (Cap-NO·H2O) is a novel crystal form of S-nitrosocaptopril (Cap-NO), and is not only a nitric oxide (NO) donor, but also an angiotensin-converting enzyme inhibitor (ACEI). Yet, a method for long-term storage has never been reported. In order to determine the optimal storage conditions, Plackett–Burman (PB) design was performed to confirm the critical factors. Response surface methodology (RSM) was employed to determine the optimal Cap-NO·H2O storage condition, based on the rough interval determined by the path of steepest ascent experiment. The optimized storage condition was denoted as nitrogen purity of 97%, temperature of −10 °C and 1.20 g deoxidizer. In this case, a final preservation rate of 97.91 ± 0.59% could be obtained. In specific storage conditions, Cap-NO·H2O was found to be stable for at least 6 months in individual PE package, procreating a potentially applicable avenue.

Characterization of an α-Amylase from the Honeybee Chalk Brood Pathogen Ascosphaera apis

“…where E is the effect of the tested variable; M + is the amylase activity from the trials where the variable was present at a high concentration; M − is the amylase activity from the experiment where the variable was present at a low concentration; and N is the total number of trials. The method of steepest ascent is a procedure for moving sequentially along the path of steepest ascent, i.e., along the path of the maximum increase in the response [30]. Based on the results of PBD experiments, the optimal level of scope of every selected variable was explored by the mean of the steepest ascent method.…”

Modelling and Simulation of Nonlinear Dynamic Flow Field and Temperature Field of Depyrogenation Tunnel

“…Compared with the far-infrared radiation sterilization method, the implementation process of dry heat sterilization is more controllable in the control of temperature and pressure difference, and it is more in line with Good Manufacturing Practice (GMP) requirements, resulting in higher sterilization quality and efficiency [1,2]. Consequently, under this premise, the control of the temperature and the control of differential pressure of the sterilization depyrogenation tunnel have become the key control parameters of the equipment.…”