Assessment of the solid-state composition of an active salicylanilide compound by FT-Raman spectroscopy

Polymorphic characterization and bioavailability of 20(R)-25-methoxyl-dammarane-3β,12β,20-triol, a novel dammarane triterpenoid saponin, as anticancer agents

This research, for the first time, obtained and reported three novel Form I, Form II, and Form III of 20(R)-25-methoxyl-dammarane-3β,12β,20-triol polymorphs, which were distinguished by PXRD, IR, DSC, and SEM. This study firstly exploited a rapid and feasible UHPLC-ESI-MS/MS method to determine plasma levels of 20(R)-25-OCH3-PPD within 4.5min. The composition of mobile phase was acetonitrile and 5mM ammonium acetate water (85:15, v/v) at a flow rate of 0.2mL/min on the BEH C18 Column (2.1mm×50mm, 1.7μm). The approach enhanced the efficiency of analysis compared to reported methods, making a 3-fold reduction in runtimes. The research exhibited that optimal crystal Form I displays higher bioavailability (P<0.05) compared to the other crystal forms. These findings hold great significance in the early research stages of 20(R)-25-OCH3-PPD polymorphs.

Effect of milling conditions on solid-state amorphization of glipizide, and characterization and stability of solid forms

In this study, the amorphization of glipizide was systematically investigated through high-energy ball milling at different temperatures. The results of solid-state amorphization through milling indicated that glipizide underwent direct crystal-to-glass transformation at 15 and 25°C and crystal-to-glass-to-crystal conversion at 35°C; hence, milling time and temperature had significant effects on the amorphization of glipizide, which should be effectively controlled to obtain totally amorphous glipizide. Solid forms of glipizide were detailedly characterized through analyses of X-ray powder diffraction, morphology, thermal curves, vibrational spectra, and solid-state nuclear magnetic resonance. The physical stability of solid forms was investigated under different levels of relative humidity (RH) at 25°C. Forms I and III are kinetically stable and do not form any new solid-state forms at various RH levels. By contrast, Form II is kinetically unstable, undergoing direct glass-to-crystal transformation when RH levels higher than 32.8%. Therefore, stability investigation indicated that Form II should be stored under relatively dry conditions to prevent rapid crystallization. High temperatures can also induce the solid-state transformation of Form II; the conversion rate increased with increasing temperature.

FT-IR, FT-Raman and DFT calculations of 4-chloro-2-(3,4-dichlorophenylcarbamoyl)phenyl acetate

FT-IR and FT-Raman spectra of 4-chloro-2-(3,4-dichlorophenylcarbamoyl)phenyl acetate were recorded and analyzed. Synthesis and elemental analysis are also reported. The vibrational wavenumbers of the compound have been computed on the basis of density functional theory using B3LYP/6-31G* basis set. The predicted infrared intensities and Raman activities are reported.

Quantitative determination of diclofenac sodium in solid dosage forms by FT-Raman spectroscopy

The FT-Raman quantification of diclofenac sodium in tablets and capsules was performed with the help of the partial least squares (PLS), principal component regression (PCR) and counter-propagation artificial neural networks (CP-ANN) methods. For the analysed tablets, calibration models were built using unnormalised spectra and spectra normalised by the intensity of a selected band of an internal standard. Different pre-processing methods were applied for the capsules. To compare the predictive ability of the models, the relative standard errors of prediction (RSEP) were calculated. The 5 x 5 CP-ANN and PLS methods gave models of comparable quality, which were usually more efficient than the PCR ones. The RSEP error values for the tablets were in the range of 2.4-3.8% for the calibration and 2.6-3.5% for the validation data sets and for the three procedures applied. For capsules, the RSEP errors were in the range of 0.8-1.9% and 1.4-1.7% for the calibration and validation samples, respectively. Five commercial products containing 25, 50 or 75 mg of diclofenac sodium per tablet/capsule were quantified. Concentrations found from the Raman data analysis agree with the results of the reference analysis and correlate strongly with the declared values with the recovery of 99.5-101.3%, 99.7-102.0% and 99.9-101.2% for the PLS, PCR and CP-ANN methods, respectively. The proposed procedure can be a fast and convenient alternative to the standard pharmacopoeial methods of diclofenac sodium quantification in solid dosage forms.