Résumé
The purity of 4,4′-dimethoxy-5,6,5′,6′-bis (methylenedioxy)-2′-morpholine methylenebiphenyl-2-methyl formate methanesulfonate (IMH), a new drug for fatty liver treatment, was determined through differential scanning calorimetry (DSC). Analysis of two-factor non repeatability method was performed in the investigation the effects of two factors (heating rate and sample weight) on purity determination. The DSC experimental parameters were optimized as follows: heating rate was 10 ℃·min-1, temperature range was 150-300 ℃, sample weight was 2.0-4.1 mg, and N2 flow rate was 80 mL·min-1. The linear correlation coefficient (r) of this DSC method was 0.999 8. The RSD value (n = 6) of precision was 0.03%. The standard value and uncertainty of the purity results of the multiple batches of IMH drugs were (99.74 ± 0.29)%, (99.91 ± 0.28)%, (99.90 ± 0.28)%, and (99.81 ± 0.28)% with inclusion factor (K) of 2 and confidence probability (P) of 0.95. The results were basically consistent with the results of the mass balance method. The DSC mehod is a simple, rapid and accurate method, and provides a new reference method for determining the purity of IMH drugs, improves the accuracy and reliability of purity determination.
Résumé
OBJECTIVE: To establish an HPLC method and potentiometric titration method for the determination of escitalopram oxalate and its related substances for quality control.
Résumé
<p><b>BACKGROUND</b>The infection risk of natural orifice transluminal endoscopic surgery (NOTES) is of concern. The aim of this study was to assess the safety of NOTES by investigating the intraperitoneal bacterial load during transgastric and transvaginal procedures with antiseptic or controlling perioperative preparation.</p><p><b>METHODS</b>Forty-five female pigs were randomly assigned to five equal groups: the transgastric (TG) control group (group A), the TG middle volume gastric lavage group (group B), the TG high volume lavage group (group C), the transvaginal (TV) control group (group D) and the TV study group (group E). The study groups received gastric or vaginal lavage and abdominal antimicrobial irrigation, while the control groups received neither. All animals were administered intravenous antibiotics, underwent NOTES peritoneoscopy and transumbilical laparoscopic cholecystectomy under NOTES view with sterile instruments. The viscerotomy was closed by laparoscopic suture. The animals were observed until necropsy was performed 14 days postoperatively. Quantitative bacteriologic cultures were taken from the gastric or vaginal aspirate before and after lavage; peritoneal fluid was collected before and after peritoneal irrigation and at necropsy.</p><p><b>RESULTS</b>The surgical procedures were completed for all the pigs and all of them survived. The mean operative time of the TG group and the TV group was (81 ± 27) minutes and (66 ± 12) minutes, respectively. All animals survived for 14 days. At necropsy, significantly more peritoneal infections were noted in group A than in group D (5:9 vs. 0:9; P < 0.05). No gross evidence of intra-peritoneal infection was found in groups B, C, D and E. Bacteriological evidence was seen in all pigs in group A, 7 pigs in group B, 6 pigs in group D, and none in groups C and E.</p><p><b>CONCLUSIONS</b>Without gastric or vaginal lavage and antibiotic peritoneal irrigation, the TG procedure has a higher infection rate than the TV access. After antiseptic preparation, the bacterial load significantly decreased in the TG group, which seems as safe as the sterile TV approach.</p>