ABSTRACT
A simple HPLC-UV method was developed and validated for the quantitation of RP free base encapsulated into two new multiparticulate systems (microparticles and nanoparticles), as well as for the quantification of RP hydrochloride when given as a loading dose together with the new delivery system developed. HPLC separation was achieved using a C18 Kromasil column (250 mm × 4 mm) with a mobile phase composed of acetonitrile-phosphate buffer solution (55:45, v/v) adjusted at pH 6.0 and containing 0.3% triethanolamine. Flow rate was set at 1.0 mL min(-1). The UV detector was operated at 245 nm. The method allowed for the simultaneous determination of both RP and RP-HCl. The method was linear within the range 2.5-50 µg mL(-1) for both RP and RP-HCl. The limits of detection (LOD) and quantitation (LOQ) found were 0.8 µg mL(-1) and 2.4 µg mL(-1) for RP, and 0.3 µg mL(-1) and 0.9 µg mL(-1) for RP-HCl. The method was found to be simple, rapid, specific, precise, accurate, and reproducible. The method was successfully applied to the determination of the encapsulation efficiency of RP in the multiparticulate systems developed, being 85.03 ± 3.77% and 51.12 ± 3.50%, for RP-loaded PLGA microspheres and RP-loaded PLGA nanoparticles, respectively.
Subject(s)
Antiparkinson Agents/administration & dosage , Antiparkinson Agents/analysis , Indoles/administration & dosage , Indoles/analysis , Calibration , Chromatography, High Pressure Liquid , Drug Delivery Systems , Excipients , Lactic Acid , Limit of Detection , Microspheres , Nanoparticles , Polyglycolic Acid , Polylactic Acid-Polyglycolic Acid Copolymer , Reference Standards , Reproducibility of Results , Spectrophotometry, UltravioletABSTRACT
Treatment of malignant gliomas consists of resection followed by radiotherapy and chemotherapy. Celecoxib (CXB), a selective COX-2 inhibitor, is able to control inflammation and pain, to improve the efficacy of radiotherapy, and to inhibit at high doses the growth of cancer cells. Two new delivery systems for CXB are developed: microspheres (MPs) for implantation in the brain after partial/complete removal of the tumor, and nanoparticles (NPs) for their potential to cross the blood brain barrier and deliver CXB into the CNS. Cell culture assays performed in PC12, SKN-AS and U373-MG cells demonstrate the antiproliferative affects of CXB, with EC50 values of 99.81 µM and 82.4 µM in U373-MG and SKN-AS cells. Encapsulation efficacy of CXB in formulation MP2 (20% CXB) was 74.6 ± 2.2% with a zero-order release rate of 47.8 µg/day/20mg microspheres for 34 days. Uncoated and polysorbate 80-coated CXB-NPs are prepared by nanoprecipitation. Mean sizes of uncoated and coated CXB-NPs were 173.6 ± 44.9 nm and 100.6 ± 62.1 nm. Cerebral cortex images showed a marked increase of fluorescence when the surfactant-coated NPs were administered to rats. These results suggest that both CXB formulations (MPs and NPs) are adequate systems to enhance the effects of chemotherapy in the treatment of malignant brain tumor.
