For the minimized phase transtorming risk, the most stable polymorph is generally considered as the desirable solid form for pharmaceutical applications. However, occasionally, the stable form may have some shortcomings such as low solubility, dissolution rate and bioavailability, etc. In that case, the metastable form which is kinetically stable at room or lower temperature could be selected. Using metastable form may result in polymorph transformation in pharmaceutical manufacture and storage. Hence, the knowledge of the transformation between solid forms is essential to the development of the drug materials. In this paper, we will review the recent studies in the area of crystal conversion of polymorphs and hydrates, to illustrate some cases to introduce the types, conditions and mechanisms of the crystalline solid transformation.
Biological Availability ; Chemistry, Pharmaceutical ; methods ; Crystallization ; Drug Stability ; Kinetics ; Pharmaceutical Preparations ; chemistry ; Solubility

Objeclive To investigate the relationship between carotid atheroselemtic(CAS)plaque and homocysteine(HCY),C-reactive protein(CRP)and ischemie eerebrovasclar desease(ICVD).Methods 468 patients with ICVD and 456 patients without eerebrovaseular disease(control group)were detected by carotid color duplex in IMI,number,size and character of carotid atherosclerosis(CAS) plaque and thelevels of HCY and CRP were evaluated,and compared with normal control group.Results(1)Compare with control group,the IMT,prevalence of CAS plaque,the rates of soft plaque in ICVD group were significantly higher(all P＜0.05).(2)The levels of HCY and CRP in ICVD were significantly higher than those in control group(P＜0.05),and in ICVD with plaque subgroup were significantly higher than those in ICVD without plaque subgroup(P＜0.05).(3)The prevalence of CAS plaque and IMT were positively correlated with the levels of HCY and CRP(r=0.32,0.30 repectively,P＜0.05).Condusion ICVD patients show increased IMT and hJish prevalence of CAS plaque.CAS plaque and hyperhomocystoinemia is an independent risk factor for ICVD.The level of CRP is an important biological marker to evaluate the severity and prognosis of ICVD.

Objective To explore the changes and the clinical signficance in serum myocardial zymogram of patients with intracerebral be hemorrhage(ICH).Methods To estimate the serum myocardial zymogram.Serum aspartate aminotrasferase(AST),lactate dehychogenase (LDH),creatine kinas (CK) in patients with ICH were measured in 3 days,then to make comparison with control group.Results The serum myocardial zymogram in ICH group were higher than that of control group(P <0.05).There were different changes in serum myocardial zymogram of various parts.The serum myocardial zymogram in group with temporal lobe damage was higher than that of group without temporal lobe damage (P < 0.05).The serum myocardial zymogram of group with colliculus brain damage was higher than that of group without colliculus brain damage(P <0.05) ,the serum myocardial zymogram of group with disorder of consciousness was higher than that of group wakefulness(P < 0.05).Conclusion There are significant changes in the serum myocardial zymogram of patients with ICH.The incidence of the serum myocardial zymogram in ICH was close]y correlated to the severity area and part of ICH,consciousness disorder.To estimate serum zymogram is helpful to judge patients' state and prognosis.

0.05).The degree of angiostegnosis:1-grade stenosis in MSCTA was higher than that in DSA.The 2-grade,3-grade and 4-grade stenosis in DSA were higher than that in MSCTA(all P

Objective To evaluate left ventricular regional volume and function of the patients with myocardial infarction by real-time three-dimensional echocardiography.Methods The study consisted of 24 normal subjects and 27 patients with myocardial infarction.Three-dimensional image data were acquired and were analysed offline.Regional volume curves and regional ejection fraction curves were derived.Regional diastolic volumes,regional systolic volumes and regional ejection fractions were compared respectively between two groups.Results The normal regional volume curves and regional ejection fraction curves were regular parabola.The regional volume increased and ejection fraction decreased in the zones with infarction,and the amplitudes of the regional volume curves and the regional ejection fraction curves decreased.Conclusions Real-time three-dimensional echocardiography can evaluate left ventricular regional volume and regional function objectively.

Objective To investigate the correlation of the plasma homocysteine level and serum B/apolipoprolionAl(ApoB/ApoAl) radio with cerebral vascular stenosis in patients with cerebral infarction.Methods 184 patients with cerebral infarction experienced cerebral digital substraction angiography (DSA) were selected.Among them,158 patients with cerebrovascular stenesis and 26 patients without stenosis were included.Three groups were categorized by distribution of artery lesion sites:isolated intracranial artery stenesis ( n =48 ),isolated extracranial artery stenosis( n =60) co-existing of intracranial and extracranial artery stenosis( n =50).The correlation analysis was made between the levels of Hcy and ApoB/ApoAl with cerebral vascular stenosis in patients with cerebral infarction.Results ( 1 ) The proportion of subjects with high level of plasma homocysteine was significantly higher in patients with cerebrovascular stenosis than those without[( 16.9 ±8.1 ) μmol/L vs (8.6 ±4.6) μmol/L,P ＜0.001 ;40％ vs 0,P ＜0.01].The proportion of subjects with high level of ApoB and ApoB/ApoA1 ratio was significantly higher in patients with cerebrovascular stenosis than those without ApoB [( 1.02 ± 0.25 ) vs ( 0.86 ± 0.22 ) g/L,P ＜ 0.01],ApoB/ApoAl ratio [( 0.94 ± 0.50) vs ( 0.64 ± 0.21,P ＜ 0.01 )].(2) For the different groups of artery lesion sites,the proportion of subjects with high level of plasma homocysteine was not significantly different[( 16.1 ± 8.5 )mml/L、( 17.0 ± 8.9 ) mmol/L、( 16.7 ± 8.7 ) mmol/L,P ＞ 0.05],the proportion of subjects with ApoB/ApoAl ratio was not significantly different [0.98 ± 0.45,0.93 ± 0.48,0.96 + 0.50,P ＞ 0.05].(3) Based on multivariable stepwise Logistic regression model,the increased level of Hcy( OR =1.146,95％ CI:1.021 ～ 1.287 ;P =0.021 ),the increased level of ApoB/ApoAl ( OR =4.71,95 ％ CI:1.70 ～ 14.20,P =0.005 ),the increased level of ApoB ( OR =4.50,95 ％ CI 为 1.62 ～ 12.80,P =0.007),the increased level of Cho ( OR =2.406 ;95％ CI:1.145 ～ 5.055 ; P =0.023 ),the decresed level of HDL( OR =0.089,95％ CI:0.014 ～ 0.551,P =0.017 ) were all risk factors.Conclusion High level of plasma homocysteine and ApoB/ApoAl were both independent risk factors for cerebral vascular stenosis.

Adult ; Dimethylformamide ; poisoning ; Female ; Humans ; Occupational Exposure ; Young Adult

Objective To explore the efficacy and safety of low-dose ketamine for prevention of shivering during cesarean section under subarachnoid space and epidural anesthesia.Methods Ninety pregnant women who scheduled cesarean delivery under subarachnoid space and epidural anesthesia were randomized divided into three groups:control group (30 patients) low-dose ketamine group (30 patients) and high-dose ketamine group (30 patients).0.9％ sodium chloride,0.25 mg/kg(3 ml),and 0.50 mg/kg (3 ml) ketamine were given in three groups before operation.The incidence of shivering and adverse effect were recorded respectively before anesthesia,after anesthesia 15 min and 30 min and after operation 1 h.Results The level of mean arterial pressure (MAP) in control group after anesthesia 15 main and 30 min and after operation 1 h[(62 ± 10),(58 ± 8),(61 ± 11) mm Hg(1 mm Hg =0.133 kPa)] were significantly lower than those in high-dose ketamine group [(78 ± 12),(82 ± 8),(76 ± 11)mm Hg] and low-dose ketamine group [(72 ± 10),(76 ± 6),(80 ± 7) mm Hg],there was significant difference (P ＜ 0.05).There was no shivering need treat in low-dose ketamine group and high-dose ketamine group.The rate of hallucinations and nystagmus in low-dose ketamine group [0,6.7％ (2/30)] was significantly lower than that in high-dose ketamine group [20.0％ (6/30),50.0％ (15/30)],there was significant difference (P ＜ 0.05).Conclusion The pretreatment with low-dose ketamine on shivering during cesarean section under subarachnoid space and epidural anesthesia has better preventive effectiveness,0.25 mg/kg of ketamine is more effective than 0.50mg/kg.

Objective To explore the risk factors of the recurrence of ischemic stroke and to supply theoretical basis for secondary prevention.Methods 612 patients with ischemic stroke were enrolled in the study and they were followed-up for 2 years to record the stroke recurrence.According to whether the recurrent stroke occurred,all the patients were divided into the recurrent group and the non-recurrent group.Logistic regression model was used to analyze the risk factors.Results Of 612 patients,90 patients suffered from recurrent stroke and the recurrence rate after 2 years was 14.7％.In the recurrent group,age,smoking,hypertension,diabetes,fibrillation atrial history and homocysteine level were significantly higher than those in non-recurrent group (P ＜ 0.05),compliance of anti-platelet drugs was significantly lower than that in non-recurrent group (P ＜ 0.01).Multivariate analysis suggested that age,smoking,hypertension,diabetes,atrial fibrillation history,homocysteine level and compliance of anti-platelet drugs were associated with recurrence of ischemic stroke (OR value =11.14,47.38,53.11,111.12,53.11,40.98,90.12,all P ＜ 0.05).Conclusion Age,smoking,hypertension,diabetes,atrial fibrillation history,homocysteine level and compliance of anti-platelet drugs are the independent risk factors of recurrent stroke.To enhance the interference of these risk factors are helpful for preventing the recurrence of stroke.