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 explore the higher dangerous factors,the early clinical performances and its contents of neonatal pulmonary hemorrhage(NPH).Methods The clinical performances,chest radiograms and autoptical pathological materials of 66 cases of newborns who died of NPH at our neonatal department during 1993 to 2003 were reviewed and analyzed.Results The higher dangerous factors of NPH were premature delivery/low birth weight,serious diseases lead to hypoxia and severe infections.The early clinical performances of NPH were the suddenly aggravation of dyspnea and the increasing of moist sounds.The early X-ray performances were lower penetrance of lung fields extensively and well-distributly with path clouds,the intercostals space usually increased.According to the autoptical(patho)-logy,this X-ray perfomance indicated the edema of the pulmonary with small amount of hemorrhage.Conclusion The patients with the higher dangerous factors and the early clinical performances of NPH,must be diagnosed and interfered it as early as possible to reduce the mortality of NPH.

Objective To share our experience in the placement of a peripherally inserted central cathe -ter ( PICC) in critically ill patients intensive care unit ( ICU) .Method The clinical data of a critically ill pa-tient placed with PICC from neurosurgery department were collected and analyzed .Result A 78-year-old male patient diagnosed with type I respiratory failure , aspiration pneumonia , hypertension , and cerebral infarction sequelae successfully received ultrasound-guided modified Seldinger puncture technique for PICC and was trea-ted with intravenous nutrition after repeatedly vascular puncturing failure .Conclusion PICC placement is an effective method for patients in ICU to protect the peripheral vein and lower the incidence of catheter related in -fections.

OBJECTIVE: To study in vitro percutaneous permeability of methylphenidate cream. METHODS: Isolated rat skin was taken as permeable barrier. The influence of different concentrations of azone(0%, 2%. 5% ) in methylphenidate cream on drug permeation was observed. RESULTS: Steady-state percutaneous flow(J ) of methylphenidate cream with 2% and 5% azone increased 27. 80% and 49. 05%. respectively. CONCLUSION: Methylphenidate cream will be a safe. effective and conve- nient new preparation.

Under the condition of the inevitable development trend of teachers' specialization in the world,this paper discusses the professional quality and existing problems of the medical physics teachers and the development ways to realize the teachers' specialization in medical physics.

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.