title: Formulation and evaluation of controlled release ethylcellulose and polyethylene glycol microspheres containing metoprolol tartrate.
abstract: Metoprolol tartrate is rapidly absorbed from both gastric and intestinal regions, after oral administration. To retard the release rate of the metoprolol tartrate, microspheres were prepared with varying concentrations of a mixture containing ethylcellulose and polyethylene glycol-6000. The prepared microspheres were evaluated for various physicochemical characteristics andin vitrodrug release. The percent yield of microspheres was in the range of 75.2-87.3%. The particle size of microspheres was found to be in the range of 73.2-85.5 μm. Fourier transform-infrared spectral analysis and differential scanning calorimetry concluded the absence of any interaction between the drug and the carriers. The release time profile of metoprolol tartrate from microspheres in 0.1 N hydrochloric acid solution was to the extent of 33.4-60.2%. The complete release of metoprolol tartrate occurred from MPT-3 and MPT-4 in phosphate buffer solution (pH 7.4) within 8 and 7 h, respectively, whereas the incomplete release (72.3%) occurred from MPT-1. Nearly, the complete release (98.5%) of metoprolol occurred from MPT-2 in 10 h. Formulation MPT-2 would be a preferred formulation. The release of metoprolol involves diffusion rate limited (R2= 0.9865) as a mechanism from drug release. The prepared microspheres of metoprolol tartrate eliminate the need for multiple dosing and provide patient compliance.
authors.affiliation: Amity Institute of Pharmacy, Amity University , Lucknow, Uttar Pradesh, India.
authors.forename: Venkata Ramana
authors.initials: VR
authors.lastname: Malipeddi
authors.affiliation: Laureate Institute of Pharmacy , Kangra, Himachal Pradesh, India.
authors.forename: Rajendra
authors.initials: R
authors.lastname: Awasthi
authors.affiliation: School of Pharmacy and Biomedical Sciences, The University of Newcastle , Newcastle, Australia.
authors.forename: Kamal
authors.initials: K
authors.lastname: Dua
keywords: antihypertensive drugs; controlled drug delivery; metoprolol tartrate; microspheres; solvent evaporation