Polymorphism of drug is known to influence the stability, dissolution, bioavailability and other performance characteristics of the products. Therefore, the crystal form of the drug must be identified and determined in order to ensure consistent product performance. Even if the identification and characterization of crystal forms are performed thoroughly and the effective crystal form is selected for preparation, it is important to ensure that the effective crystal form in the final product remains unchanged. Therefore, it is essential to quantitate the content of the effective crystal form in the product to control the quality and performance of them. X-ray powder diffraction, FT-Raman, mid-IR, near-IR, terahertz pulsed spectroscopy, solid-state NMR spectroscopy, and DSC are the quantitative methods of crystal form used in the recent 10 years. This review briefly highlights the basic principles and the progress of these methods and discusses the perspective as they apply to pharmaceutical research and development.

Objective To investigate the clinical efficacy of CO2 lattice laser combined with 595 nm pulsed dye laser in the treatment of cesarean section skin scar.Methods A total of 60 patients with cutaneous scar after cesarean section in our hospital from June 2015 to October 2017 were enrolled.The patients were divided into observation group and control group according to the order of hospitalization.Each group had 30 cases.Both CO2 lattice and 595 nm pulsed dye lasers were used in study group.Only CO2 lattice laser was used in control group.Vancouver scar scale (VSS) and adverse reactions were analyzed after treatment in both groups.Results The two groups were compared at 3 months and 6 months after treatment.The VSS scores of the study group were (52.00± 1.31) and (3.81±1.38),which was significantly lower than that of the control group (6.30±1.21) and (5.00± 1.38).The difference was statistically significant (t =3.175,3.35,P ＜0.05).There were no significant differences in adverse reactions between the two groups (P＞0.05).Conclusions CO2 dot laser combined with 595 nm pulsed dye laser for the treatment of cesarean section skin scar is more effective than CO2 dot matrix laser alone.