Der Pharmacia Lettre
Abstract
Author(s): Prakash Bhagav, Pandurang Deshpande, Saurabh Pandey, Sajeev Chandran
A new simple, sensitive and selective UV- spectrophotometric method was developed and
validated for the estimation of brimonidine tartrate (BRT) in bulk and in formulations. The
method was also applied for the determination of drug solubility, apparent partition coefficient
and pKa. BRT was estimated at 248 nm in phosphate buffer (pH 7.4). The linearity range was
found to be 3-18 ?Ž?¼g/ml with a regression equation of Absorbance = 0.0630 ????? (concentration in
?Ž?¼g/ml) + 0.0050. The LOD and LOQ were found to be 0.15 ?Ž?¼g/ml and 0.45 ?Ž?¼g/ml respectively.
The method was found to be accurate (mean percentage accuracy of 99.92) and precise with %
RSD less than 1.97 (for intra-day) and less than 1.36 (for inter-day). The developed method was
successfully employed for the determination of BRT in pharmaceutical dosage forms (ophthalmic
solutions, ocuserts and gels). Forced degradation studies with acid, alkali and temperature
based stress conditions showed that the method is stability indicating. The determined
preformulation parameters (solubility, apparent partition coefficient and pKa) were found to be
similar to the earlier reported results.
