ABSTRACT
Objective: To reduce the frequency of administration of tamoxifen citrate so as to improve its bioavailability and patients’ compliance. Methods: HPMC K4M was employed as major retarded release controller. The wetting granulation and directly compressing method was used to produce the sustained release tablet. Then the in vitro release profile was applied as main criteria to evaluate six formulations according to the variation of HPMC K4M amount. The concentration of tamoxifen citrate was measured by UV spectrometry. Finally the releasing characteristics of sustained release and conventional tablets were compared to clarify the sustained effect of the former. Result: At 278 nm there was no interaction between tamoxifen citrate and the recipients so that it was adopted as the wavelength of determination. The recovery efficiency of this method ranged from 95%-105%. The final formulation could release 86.40% of its loading amount in 12 h and its releasing profile fitted the Zero order equation well. The percentages of accumulative release in 1 h were 76.81% and 7.08% for sustained release tablet and conventional tablet respectively. Conclusion: The sustained release tablet of tamoxifen citrate could demonstrate a continuous and stable releasing profile and last for over 12 h. It has significant retarded effect in comparison with the conventional one and could be a new choice of regimen in its clinical application.
ABSTRACT
Objective To investigate the occurrence of cesarean section (CS) among reproductive age women in last thirty years, and explore the factors related to high CS rate. Methods Population proportional to size sampling method was employed in sampling. The sampled women were interviewed face to face. Data were double entered by EPIDATA 2.1 and analyzed by SPSS 11.5. Results The CS rate continuously increase from 0.9% in 1971-1980 to 20.2% in 2001-2002 and the speed is more and more rapid. More and more CSs were required by the women themselves and the rate increased from 19.3% in 1971-1985 to 49.7% in 2001-2002. Logistic regression analysis showed that women who were less than 30, senior high education or above and white-collar or jobless women had more than 8 times of antenatal visits, lived in eastern region and had B-ultrasound exam, were more likely to have caesarean section. Conclusions The caesarean section rate was increasing rapidly in the last thirty years especially after 1990. There are two reasons for this increase, on one hand caesa- rean sections with medical indications increase because of the progress of perinatal care and related technology; on the other hand unnecessary caesarean sections increase because of some social and demographic factors, which result in more caesarean section required by the pregnant women.