Estimating Butylated Hydroxytoluene in the Presence of Polymers such as Polyethylene Glycol and Polyethylene Oxide in Mirabegron Extended-Release Tablets

The RP-HPLC technique was utilized to develop and validate a simple LC method for the estimation of BHT (butylated hydroxytoluene) in the presence of mirabegron, PEG (polyethylene glycol), and PEO (polyethylene oxide) high molecular weight polymers. Separation was achieved using a Waters X bridge C18 (250 × 4.6) mm, 5 μm, with a suitable mobile phase. To prepare for the mobile phase, we mixed acetonitrile and triethylamine buffer pH 2.0 in a ratio of (70:30) v/v. The optimized chromatographic conditions include a flow rate of 2.0 ml min^–1, injection volume of 50 μl, column temperature of 45°C, and sample detection at 210 nm. The proposed method is significant because BHT is usually used in food and cosmetics products; however, at present, it is used in ER tablets, making the extraction mechanism complicated in the presence of polymers. The amount of BHT contained in this product is 0.16 %; hence, the estimation of BHT content is difficult. Therefore, we used the proposed LC and sample preparation methods to address all the problems. Moreover, this method was validated following current ICH and USP, CPguidelines.