Evaluation of alternative diluents for clinical use of collagenase clostridium histolyticum (CCH-aaes).

BACKGROUND: Collagenase clostridium histolyticum (CCH-aesthetic formulation [CCH-aaes]; QWO™ [Endo Aesthetics, Malvern PA, USA] is approved as a subcutaneous injection for treatment of cellulite. In the aesthetic practice, dilution of marketed products is commonly employed to tailor treatments to individual patients or off-label locations. Dilution beyond the 0.23 mg/ml achievable with the proprietary diluent supplied with the CCH-aaes lyophilized powder requires diluents readily available in clinic. AIM: To characterize the functionality and stability of CCH-aaes when reconstituted and/or diluted with alternative diluents, including normal saline, bacteriostatic saline, and/or proprietary diluent. PATIENTS/METHODS: Each dilution was assessed for purity using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE), activity using collagenase (AUX-I) and gelatinase (AUX-II) assays, and aggregation using size-exclusion chromatography. RESULTS: When reconstituted with either saline or proprietary diluent, and diluted with proprietary diluent or saline, purity, activity, and stability of CCH-aaes is maintained for up to 24 h at 5°C or 25°C. In contrast, use of bacteriostatic saline to reconstitute and/or dilute CCH-aaes results in up to a 40% decrease in activity and aggregation of 5.3% of CCH-aaes protein. Importantly, inclusion of 2% lidocaine and 1:200 000 epinephrine does not negatively impact CCH-aaes purity, concentration, or activity for up to 24 h at 5°C or 25°C. CONCLUSIONS: From an efficacy and safety perspective, CCH-aaes must not be/should not be reconstituted and/or diluted with bacteriostatic saline to avoid injection of protein aggregates. Ideally, CCH-aaes should be reconstituted in proprietary diluent: further dilution with normal saline and addition of lidocaine and epinephrine is acceptable.

Formulation and characterization of Paclitaxel, 5-FU and Paclitaxel + 5-FU microspheres.

The purpose of this study was to compare the combination (Paclitaxel + 5-FU microspheres) with a single drug chemotherapy (Paclitaxel and 5-FU microspheres) against metastatic breast cancer cell line (MDA-MB 435 S). The physicochemical characteristics of the microspheres (i.e. encapsulation efficiency, particle size distribution, in vitro release, thermal characteristics) were studied. The results demonstrated that the encapsulation efficiency of Paclitaxel was high (90%) when the drug was encapsulated in poly(lactic-co-glycolic acid) (PLGA) microparticles with or without 5-fluorouracil (5-FU). However, the encapsulation efficiency of 5-FU was low (19%) and increased to 30% when the drug was encapsulated with Paclitaxel. The mean particle size of microspheres was 2.5microm and were spherical in shape. The in vitro release of both 5-FU and Paclitaxel from the microspheres was relatively fast initially followed by a slower and more controlled release. The cytotoxic activity of Paclitaxel microspheres was far greater compared to either the microspheres containing 5-FU + Paclitaxel or 5-FU alone. Overall results demonstrated that incorporation of Paclitaxel or 5-FU in microspheres enhances the cytotoxicity in more controlled manner compared to that of free drugs and also that careful consideration should be made when combining drugs acting in different phases of cell cycle.

Growth factors and chemotherapeutic modulation of breast cancer cells.

A variety of molecules including growth factors are involved in the metastasis of breast cancer cells to bone. We have investigated the effects of osteoblast derived growth factors, such as insulin-like growth factor-1 (IGF-1) and transforming growth factor beta-1 (TGF-beta1), on doxorubicin (adriamycin)-induced apoptosis and growth arrest of estrogen receptor positive (ER+) (MCF-7) and negative (ER-) (MDA-MB-435) breast cancer cell lines. Human breast normal epithelial (MCF-10A), breast cancer (MCF-7) and metastatic breast cancer (MDA-MB-435) cell lines were exposed to different doses of doxorubicin (0.1, 1 or 10 microM) at various exposure times (12, 24 or 48 h). The doxorubicin cytotoxicity was found to be higher in cancer cell lines (MDA-MB-435 and MCF-7) compared with normal breast epithelial cells (MCF-10A cells). Doxorubicin appeared to exert a blockade of MCF-7 and MDA-MB-435 cells at the G2/M phase, and induced apoptosis in MDA-MB-435 (29 +/- 4.2% vs 3.4 +/- 1.9% control) as assessed by flow cytometry, DNA fragmentation and terminal deoxynucleotidyl-transferase mediated deoxyuridine 5-triphosphate and biotin nick-end labelling (TUNEL) assays. Estradiol (E2) stimulated the growth of MCF-7 cells and increased the distribution of the cells at the G2/M and S phases. Exogenous IGF-1 partially neutralized the doxorubicin cytotoxicity in both cancer cell lines (MCF-7 and MDA-MB-435). Similarly, TGF-beta1 partially neutralized the doxorubicin cytotoxicity in MDA-MB-435 cells by reducing the number of cells at the

Changes in BRCA1 and BRCA2 expression produced by chemotherapeutic agents in human breast cancer cells.

We have investigated the effects of chemotherapeutic agents such as adriamycin (ADR), camptothecin (CPT), mitomycin-C (MYC-C) and methotrexate (MTX) on the regulation of expression of the tumor susceptibility genes (BRCA1 and BRCA2), and the association of cell cycle progression in human breast cancer and normal breast epithelial cells. Results revealed that the mRNA and protein expression levels of BRCA1/2 were reduced by the treatment of chemotherapeutic agents used in the breast cancer cell lines tested, with ADR being the most effective. The regulation of the cell cycle was dose-dependent and low doses of ADR (1.5 microM) induced G2/M phase arrest whereas a late S phase arrest was observed with a higher dose of ADR (15 microM) in both breast cancer cells (MCF-7 and MDA-MB-231) tested. In addition, a negative correlation was observed between BRCA1/2 mRNA and expressions of the proteins with the cell cycle alterations being regulated by chemotherapeutic agents.