In this study,a new class of biodegradable contraceptive implants was prepared via the UV irradiation molding method,among which,progestin levonorgestrel(LNG)was used as a model drug.Photo-cross-linked aliphatic polyc...In this study,a new class of biodegradable contraceptive implants was prepared via the UV irradiation molding method,among which,progestin levonorgestrel(LNG)was used as a model drug.Photo-cross-linked aliphatic polycarbonates(APCs),namely,poly(trimethylene carbonate-co-2,2′-dimethyltrimethylene carbonate)[P(TMC-co-DTC)]elastomers,were used as the drug delivery matrix.The results obtained from the degradation experiments carried out in Sprague-Dawley(SD)rats showed that the cross-linked elastomer had the degradation characteristics of the surface erosion degradation mechanism,with no generation of acid degradation products,and excellent form-stability,which met the performance requirements of the matrix for a long-acting sustained-release delivery system.The in vitro cytotoxicity tests and histological and immunohistochemical evaluations showed good biocompatibility and biosafety of the elastomer matrix material and contraceptive implants.Subsequently,the implant formulations were screened by in vitro release experiments,and their release kinetics were explored.Finally,in the evaluation study of the in vivo anti-fertility effect,the implants exhibited excellent dimensional stability and were degraded by a surface erosion mechanism.LNG achieved a stable and sustained release in female SD rats,maintaining a long-acting contraceptive duration of up to 4 months.The contraceptive implants obtained in this study could be used to address the limitations of currently available formulations,which required secondary surgical removal and a single means of regulating drug release kinetics.Therefore,these implants could provide a new option for birth control needs and may be of significance in reducing the incidence of induced abortion and protecting female fertility.展开更多
Objective: To compare the efficacy, side-effects and acceptability of domestic produced implant No. I and No. II with Norplant. Method: A multicentered randomized prospective clinical trial was conducted in ten center...Objective: To compare the efficacy, side-effects and acceptability of domestic produced implant No. I and No. II with Norplant. Method: A multicentered randomized prospective clinical trial was conducted in ten centers in Chi na since 1993. Every center have recruited 100 cases for each of the three types of implants. Results: Altogether l, 001 cases of No. I, 1, 000 cases of No. II and 998 cases of Norplant were recruited. The follow--up rate was 99. 2% at the end of 24 months and 99. 1% at the end of 36 months. One pregnancy in No. I implant occurred & months after insertion and the net cumulative pregnancy rate was 0. 1 per 100 women. Total discontinuation rates were 15. 1, 14. 1, and 12. 9 per 100 women in NO. I, No. II and Norplant groups respectively. Among them about 75% of discontinuation was due to the menstrual problems. The incidence of side-effects were 22. 6%, 19. 0% and 19. 7% respectively at 36 months follow--up. There was no significant differences in efficacy and side effects among these three types of implant. Conclusion: The result of this three-years’ follow--up indicated that the domestic products implant No. I and No. II just as Norplant are long term, highly effective contraceptive and have been accepted in different area by different people. It will be widely selected by women of reproductive age in China.展开更多
CaproF is a biodegradable subcutaneous contraceptive implant of releasing levonorgestrel (LNG), which is expected to provide an effective contraception for 2 years. This study was undertaken to assess the one year pr...CaproF is a biodegradable subcutaneous contraceptive implant of releasing levonorgestrel (LNG), which is expected to provide an effective contraception for 2 years. This study was undertaken to assess the one year preliminary clinical results of using CaproF in 19 subjects. All subjects (n=19) completed the 1 year study, and the contraceptive effectiveness and follow up rate were both 100%. The incidence of side effects was low. The major side effects were menstrual disorder, but bleeding patterns tended to be improved and restored to be the same as pre implantation ones with time. There were no significant increase in weight (P>0.05) and no changes in blood pressure. In the 3 rd , 6 th and 12 th months after using CaproF, the cervical mucus became scanty and viscous without fern like crystals. The amount of menstrual blood loss decreased from 49.38 ml of pre implantation to 33.23 ml of the 12 th month of using the implant (P<0.05). Hemoglobin concentrations showed no changes, but serum ferritin concentrations were slightly increased. No changes in liver function, kidney function, glucose tolerance test and lipoprotein levels were found. Determinations of sex hormones (FSH, LH, E 2 and progesterone) levels, ultrasonography of ovary, and endometrial biopsy in observed group (n=9) showed that all had normal ovulation before insertion. But ovulation was suppressed and endometrium development was inhibited after insertion. All basal body temperatures were single phase patterns during the 1 year follow up. This study suggested that CaproF is an effective, safe and acceptable long acting contraceptive method. It is likely to reach its contraceptive effectiveness through suppressing ovulation, inhibiting endometrium development and influencing cervical mucus characteristics.展开更多
基金sponsored by the Natural Science Foundation of Liaoning Province(Nos.2022-YGJC-69,2021-BS-110)the support program for excellent young scholars of China Medical University.
文摘In this study,a new class of biodegradable contraceptive implants was prepared via the UV irradiation molding method,among which,progestin levonorgestrel(LNG)was used as a model drug.Photo-cross-linked aliphatic polycarbonates(APCs),namely,poly(trimethylene carbonate-co-2,2′-dimethyltrimethylene carbonate)[P(TMC-co-DTC)]elastomers,were used as the drug delivery matrix.The results obtained from the degradation experiments carried out in Sprague-Dawley(SD)rats showed that the cross-linked elastomer had the degradation characteristics of the surface erosion degradation mechanism,with no generation of acid degradation products,and excellent form-stability,which met the performance requirements of the matrix for a long-acting sustained-release delivery system.The in vitro cytotoxicity tests and histological and immunohistochemical evaluations showed good biocompatibility and biosafety of the elastomer matrix material and contraceptive implants.Subsequently,the implant formulations were screened by in vitro release experiments,and their release kinetics were explored.Finally,in the evaluation study of the in vivo anti-fertility effect,the implants exhibited excellent dimensional stability and were degraded by a surface erosion mechanism.LNG achieved a stable and sustained release in female SD rats,maintaining a long-acting contraceptive duration of up to 4 months.The contraceptive implants obtained in this study could be used to address the limitations of currently available formulations,which required secondary surgical removal and a single means of regulating drug release kinetics.Therefore,these implants could provide a new option for birth control needs and may be of significance in reducing the incidence of induced abortion and protecting female fertility.
文摘Objective: To compare the efficacy, side-effects and acceptability of domestic produced implant No. I and No. II with Norplant. Method: A multicentered randomized prospective clinical trial was conducted in ten centers in Chi na since 1993. Every center have recruited 100 cases for each of the three types of implants. Results: Altogether l, 001 cases of No. I, 1, 000 cases of No. II and 998 cases of Norplant were recruited. The follow--up rate was 99. 2% at the end of 24 months and 99. 1% at the end of 36 months. One pregnancy in No. I implant occurred & months after insertion and the net cumulative pregnancy rate was 0. 1 per 100 women. Total discontinuation rates were 15. 1, 14. 1, and 12. 9 per 100 women in NO. I, No. II and Norplant groups respectively. Among them about 75% of discontinuation was due to the menstrual problems. The incidence of side-effects were 22. 6%, 19. 0% and 19. 7% respectively at 36 months follow--up. There was no significant differences in efficacy and side effects among these three types of implant. Conclusion: The result of this three-years’ follow--up indicated that the domestic products implant No. I and No. II just as Norplant are long term, highly effective contraceptive and have been accepted in different area by different people. It will be widely selected by women of reproductive age in China.
文摘CaproF is a biodegradable subcutaneous contraceptive implant of releasing levonorgestrel (LNG), which is expected to provide an effective contraception for 2 years. This study was undertaken to assess the one year preliminary clinical results of using CaproF in 19 subjects. All subjects (n=19) completed the 1 year study, and the contraceptive effectiveness and follow up rate were both 100%. The incidence of side effects was low. The major side effects were menstrual disorder, but bleeding patterns tended to be improved and restored to be the same as pre implantation ones with time. There were no significant increase in weight (P>0.05) and no changes in blood pressure. In the 3 rd , 6 th and 12 th months after using CaproF, the cervical mucus became scanty and viscous without fern like crystals. The amount of menstrual blood loss decreased from 49.38 ml of pre implantation to 33.23 ml of the 12 th month of using the implant (P<0.05). Hemoglobin concentrations showed no changes, but serum ferritin concentrations were slightly increased. No changes in liver function, kidney function, glucose tolerance test and lipoprotein levels were found. Determinations of sex hormones (FSH, LH, E 2 and progesterone) levels, ultrasonography of ovary, and endometrial biopsy in observed group (n=9) showed that all had normal ovulation before insertion. But ovulation was suppressed and endometrium development was inhibited after insertion. All basal body temperatures were single phase patterns during the 1 year follow up. This study suggested that CaproF is an effective, safe and acceptable long acting contraceptive method. It is likely to reach its contraceptive effectiveness through suppressing ovulation, inhibiting endometrium development and influencing cervical mucus characteristics.
