RESUMO
The present investigation targets to develop a simple, specific, sensitive and accurate reverse phase high performance liquid chromatographic (RP-HPLC) method in human plasma for the estimation of metformin HCl and propranolol HCl from bulk drug and also from the marketed products. Human plasma samples were subjected to correct procedure for protein precipitation by methanol and protein free plasma samples were directly injected into HPLC C18 column. Chromatographic determination was performed on a reversed phase C18 column (3.9 mm X 300 mm, particle size 5 μm) using a mixture of acetonitrile and 0.1M pH 4.5 potassium dihydrogenortho phosphate buffer (mL) (40:60) at a flow rate of 0.8 mL/min and maintained at a pressure of 140 to 150 Kg/cm2. The retention time for metformin HCl and propranolol HCl was found to be 9.084 min and 6.132 min respectively at 232 nm without any interference of endogenous compounds in the plasma. The method was linear in the range between 50-2000 ng/mL. The peak areas were reproducible as indicated by low coefficient of variation. It was found that the excipients in the tablet dosage form do not interfere in the quantification of active drug by proposed method.
RESUMO
The aim of the present research is to formulate and evaluate the gastroretentive floating drug delivery system of antihypertensive drug, propranolol HCl. Gastroretentive floating tablets (GRFT) were prepared by using a synthetic hydrophilic polymer polyethylene oxide of different grades such as PEO WSR N-12 K and PEO 18 NF as release retarding polymers and calcium carbonate as gas generating agent. The GRFT were compressed by direct compression strategy and the tablets were evaluated for physico-chemical properties, in vitro buoyancy, swelling studies, in vitro dissolution studies and release mechanism studies. From the dissolution and buoyancy studies, F 9 was selected as an optimized formulation. The optimized formulation followed zero order rate kinetics with non-Fickian diffusion mechanism. The optimized formulation was characterised with FTIR studies and observed no interaction between the drug and the polymers.
O objetivo da presente pesquisa é o de formular e avaliar o sistema de liberação de fármaco gastrorretentivo flutuante, contendo o anti-hipertensivo, cloridrato de propranolol. Comprimidos gastrorretentivo flutuantes (GRFT) foram preparados utilizando um polímero hidrofílico sintético, o óxido de polietileno, de diferentes graus, tais como GE WSR N-12 K e GE 18 NF, como polímeros de retardamento de liberação, e carbonato de cálcio, como agente gerador de gases. Os GRFT foram comprimidos por compressão direta e avaliados para determinação das propriedades físico-químicas, flutuabilidade in vitro, estudos de inchamento, de dissolução in vitro e de mecanismo de liberação. Dos testes de dissolução e de flutuabilidade, selecionou-se F 9 como formulação otimizada. A formulação otimizada seguiu cinética de ordem zero, com mecanismo de difusão não-Fickiano. Essa formulação foi caracterizada por estudos de FTIR, não se observando interação entre o fármaco e os polímeros.