A few waxy materials like white bees wax (BW), cetyl alcohol (CA) and stearic acid (SA) as rate regulator for Metformin release from PEG-8000 based suppositories

Abstract

In order to introduce de novo advanced anti-diabetic drug delivery system like polyethylene glycol (PEG)-8000 based suppositories containing metformin (a biguanide type of anti-diabetic drug) had been developed. Various successive formulations of PEG-8000 grade in combination with many other waxy materials like BW, CA and SA had been used to prepare suppositories.The dissolution studies of metformin in PEG suppositories containing different amount of BW, SA and CA in separate formulations were carried out in an “Electrolab Tablet Dissolution Tester USP XXIII TDT”. The paddle rotation was set at 50 rpm and temperature was controlled at 37C  2C using 1 litre dissolution medium (pH 7.4). Waxy materials showed their fruitful rate controlling effect on metformin release. The kinetic constant, k values and diffusion coefficient, D decreased with an increase in waxy material in the system. The increasing k and D values indicated that the metformin release from the PEG-8000 based suppositories rate-controlled drug release, where waxy materials might play a key role like as drug-release regulator. Metformin was successfully loaded up to 1600 mg on the basis of selection of comparatively better formulation and almost Case-II transport of metformin release was found from PEG-8000 based beeswax suppository system. Metformin released for a period of 10 h approximately. Metformin might be applied using this system once a day instead of three times a day.