RESUMO
The aim of the present work was to investigate the preparation of PLGA nanoparticles (PNP) and PLGA-Hp55 nanoparticles (PHNP) as potential drug carriers for oral insulin delivery. The nanoparticles were prepared by a modified emulsion solvent diffusion method in water, and their physicochemical characteristics, drug release in vitro and hypoglycemic effects in diabetic rats were evaluated. The particle sizes of the PNP and PHNP were 150+/-17 and 169+/-16 nm, respectively, and the drug recoveries of the nanoparticles were 50.30+/-3.1 and 65.41+/-2.3%, respectively. The initial release of insulin from the nanoparticles in simulated gastric fluid over 1 h was 50.46+/-6.31 and 19.77+/-3.15%, respectively. The relative bioavailability of PNP and PHNP compared with subcutaneous (s.c.) injection (1 IU/kg) in diabetic rats was 3.68+/-0.29 and 6.27+/-0.42%, respectively. The results show that the use of insulin-loaded PHNP is an effective method of reducing serum glucose levels.
Assuntos
Hipoglicemiantes/química , Insulina/química , Ácido Láctico/química , Metilcelulose/análogos & derivados , Nanopartículas , Ácido Poliglicólico/química , Polímeros/química , Administração Oral , Animais , Glicemia/análise , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/tratamento farmacológico , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Suco Gástrico/metabolismo , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/farmacologia , Insulina/farmacocinética , Insulina/farmacologia , Secreções Intestinais/metabolismo , Masculino , Metilcelulose/química , Microscopia Eletrônica de Varredura , Nanopartículas/ultraestrutura , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos WistarRESUMO
AIM: To evaluate the in vitro/in vivo correlation for three kinds of self-designed sustained-release nitrendipine formulations using deconvolution method. METHODS: The 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. RESULTS: The good correlations of in vitro/in vivo were shown in three kinds of self-designed sustained-release nitrendipine formulations using deconvolution method. CONCLUSION: The deconvolution method exhibited advantage in evaluation of in vitro/in vivo correlation for self-designed sustained-release nitrendipine formulations.