Studies on formulation development and in-vitro release kinetics of Ramipril Micropellets for controlled release

Abstract

MicroPellets are agglomerates of fine powders or granules of bulk drugs and excipients. They consist of small, free flowing, spherical or semi- spherical solid units, typically from about 0.5mm to 1.5mm, and are intended usually for oral administration. Pellets can be prepared by many methods, the compaction and drug-layering being the most widely used Today. The study was undertaken with an aim to develop controlled release micropellets dosage form for Ramipril which is a anti hypertensive agent and is one of the most widely used drugs for treating mild and hypertension. The approach of the present these polymers and excipients and to assess the effect of physicochemical nature of the active ingredients on the drug release profile. The prototype formulation of micro pellets were prepared using the fluid bed coater (FBC) with the air pressure 2.0 bar and the spray rate 10-15ml/min. Temperature of bed is varied from 35°C to 50°C and inlet temperature is varied from 50°C to 70°C and the effect of various parameter were observed such as air pressure, inlet and outlet temperature of FBC, it is observed that at high pressure the pellets are breaking. For bed and inlet temperature it is observed that at low temperature lumps are occurring in the formulation and at 2.0 bar air pressure,inlet temperature 60°C and bed temperature of 40°C is reliable for solution flow rate 10-15ml/min. Concerning results of prototype preparation of Ramipril the micro pellets were prepared using HPMC Ethyl cellulose polymer as release retardant in six different concentration i.e. EC-14 2%, 4%, Cow ghee, EC-20 2%, 4%, 6%. Formulated micro pellets showed delayed in vitro dissolution behavior, probably due to optimized concentration of polymer. The micro pellets drug was stable at room temperature, 25°C/60% RH, 30°C/65% RH and 40°C/75% RH as per ICH guidelines, after 3 months.