AIMTo evaluate the in vitro/in vivo correlation for three kinds of self-designed sustained-release nitrendipine formulations using deconvolution method.

METHODSThe characteristics of in vivo release were calculated by deconvolution method using the data of plasma concentration of three kinds of self-designed sustained-release nitrendipine formulations in healthy dogs, in which the in vivo results of nitrendipine solution after oral administrated to dogs were used as weight function. It was the compared with characteristics of in vitro release to assess the in vitro/in vivo correlations.

RESULTSThe good correlations of in vitro/in vivo were shown in three kinds of self-designed sustained-release nitrendipine formulations using deconvolution method.

CONCLUSIONThe deconvolution method exhibited advantage in evaluation of in vitro/in vivo correlation for self-designed sustained-release nitrendipine formulations.

Administration, Oral ; Animals ; Delayed-Action Preparations ; Dogs ; Methylcellulose ; analogs & derivatives ; Microspheres ; Nitrendipine ; administration & dosage ; blood ; pharmacokinetics ; Powders ; Silicone Gels ; Technology, Pharmaceutical ; methods

To date, few studies have compared the effectiveness of topical silicone gels versus that of silicone gel sheets in preventing scars. In this prospective study, we compared the efficacy and the convenience of use of the 2 products. We enrolled 30 patients who had undergone a surgical procedure 2 weeks to 3 months before joining the study. These participants were randomly assigned to 2 treatment arms: one for treatment with a silicone gel sheet, and the other for treatment with a topical silicone gel. Vancouver Scar Scale (VSS) scores were obtained for all patients; in addition, participants completed scoring patient questionnaires 1 and 3 months after treatment onset. Our results reveal not only that no significant difference in efficacy exists between the 2 products but also that topical silicone gels are more convenient to use. While previous studies have advocated for silicone gel sheets as first-line therapies in postoperative scar management, we maintain that similar effects can be expected with topical silicone gel. The authors recommend that, when clinicians have a choice of silicone-based products for scar prevention, they should focus on each patient's scar location, lifestyle, and willingness to undergo scar prevention treatment.
Adult ; Aged ; Cicatrix/*prevention & control ; Female ; Humans ; Male ; Middle Aged ; Postoperative Period ; Prospective Studies ; Questionnaires ; Random Allocation ; Silicone Gels/*administration & dosage/*pharmacology ; Surgery, Plastic/*methods ; Surgical Procedures, Operative/*adverse effects ; Wounds and Injuries/therapy ; Young Adult

Capsular fibrosis and contracture occurs in most breast reconstruction patients who undergo radiotherapy, and there is no definitive solution for its prevention. Simvastatin was effective at reducing fibrosis in various models. Peri-implant capsular formation is the result of tissue fibrosis development in irradiated breasts. The purpose of this study was to examine the effect of simvastatin on peri-implant fibrosis in rats. Eighteen male Sprague-Dawley rats were allocated to an experimental group (9 rats, 18 implants) or a control group (9 rats, 18 implants). Two hemispherical silicone implants, 10 mm in diameter, were inserted in subpanniculus pockets in each rat. The next day, 10-Gy of radiation from a clinical accelerator was targeted at the implants. Simvastatin (15 mg/kg/day) was administered by oral gavage in the experimental group, while animals in the control group received water. At 12 weeks post-implantation, peri-implant capsules were harvested and examined histologically and by real-time polymerase chain reaction. The average capsular thickness was 371.2 μm in the simvastatin group and 491.2 μm in the control group. The fibrosis ratio was significantly different, with 32.33% in the simvastatin group and 58.44% in the control group (P < 0.001). Connective tissue growth factor (CTGF) and transforming growth factor (TGF)-β1 gene expression decreased significantly in the simvastatin group compared to the control group (P < 0.001). This study shows that simvastatin reduces radiation-induced capsular fibrosis around silicone implants in rats. This finding offers an alternative therapeutic strategy for reducing capsular fibrosis and contracture after implant-based breast reconstruction.
Administration, Oral ; Animals ; Breast/*drug effects/metabolism/pathology/radiation effects ; *Breast Implants ; Connective Tissue Growth Factor/genetics/metabolism ; Fibrosis ; Gamma Rays ; Male ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Silicone Gels/*chemistry ; Simvastatin/*pharmacology ; Transforming Growth Factor beta1/metabolism

Capsular fibrosis and contracture occurs in most breast reconstruction patients who undergo radiotherapy, and there is no definitive solution for its prevention. Simvastatin was effective at reducing fibrosis in various models. Peri-implant capsular formation is the result of tissue fibrosis development in irradiated breasts. The purpose of this study was to examine the effect of simvastatin on peri-implant fibrosis in rats. Eighteen male Sprague-Dawley rats were allocated to an experimental group (9 rats, 18 implants) or a control group (9 rats, 18 implants). Two hemispherical silicone implants, 10 mm in diameter, were inserted in subpanniculus pockets in each rat. The next day, 10-Gy of radiation from a clinical accelerator was targeted at the implants. Simvastatin (15 mg/kg/day) was administered by oral gavage in the experimental group, while animals in the control group received water. At 12 weeks post-implantation, peri-implant capsules were harvested and examined histologically and by real-time polymerase chain reaction. The average capsular thickness was 371.2 μm in the simvastatin group and 491.2 μm in the control group. The fibrosis ratio was significantly different, with 32.33% in the simvastatin group and 58.44% in the control group (P < 0.001). Connective tissue growth factor (CTGF) and transforming growth factor (TGF)-β1 gene expression decreased significantly in the simvastatin group compared to the control group (P < 0.001). This study shows that simvastatin reduces radiation-induced capsular fibrosis around silicone implants in rats. This finding offers an alternative therapeutic strategy for reducing capsular fibrosis and contracture after implant-based breast reconstruction.
Administration, Oral ; Animals ; Breast/*drug effects/metabolism/pathology/radiation effects ; *Breast Implants ; Connective Tissue Growth Factor/genetics/metabolism ; Fibrosis ; Gamma Rays ; Male ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Silicone Gels/*chemistry ; Simvastatin/*pharmacology ; Transforming Growth Factor beta1/metabolism