HPLC method for levothyroxine quantification in long-acting drug delivery systems. Validation and evaluation of bovine serum albumin as levothyroxine stabilizer

Deficiency of thyroid hormones (hypothyroidism) is treated with oral levothyroxine (LEVO). However, the effectiveness administration highly dependent on co-administration food and other drugs. This factor, in combination chronic nature this condition, mean that there are concerns patient compliance. Development long acting formulations to treat hypothyroidism could potentially solve problem. LEVO instability solution be problematic. In order develop delivery systems vitro drug release experiments should carried out. short term stability aqueous will prevent this. BSA was used as a stabiliser for LEVO; extending solutions from few hours 2 weeks. achieve this, required concentration protein 0.1% w/v. Subsequently, an HPLC method capable separating developed validated following ICH guidelines. The analysis out using reverse phase Agilent 1220 Infinity II LC system. column separation Zorbax Eclipse plus C18 (95 Å pore size, 250 mm length x 4.6 internal diameter; 5 ?m particle size). mobile composed acetonitrile trifluoroacetic acid at ratio 50:50% v/v. UV detection sodium 225 nm. retention time 6.6 minutes. showed limit 0.03 ?g/mL quantification 0.09 ?g/mL. Finally, evaluate implants containing 20% w/w LEVO. These devices were prepared solvent casting poly(caprolactone) initial burst over first 3 days. they providing linear rate 25