Improved RPLC determination of XXXX using hexylamine as @entity1039 masking agent.

@entity1033 @entity3073 @entity1042 @entity1009 @entity2774 @entity1039 @entity3440
The aim of the present work is to improve the sensitivity in the RPLC determination of @entity1033 [ @entity1033 ] ( @entity3073 ) and @entity2774 , the major impurity of the drug synthesis and one of the compounds found in the chemical degradation process of ACV. The method was applied to the quantification of drug in liposomal formulations. The most important problem for RPLC analysis of both compounds are their high pKa values, mainly @entity2774 , and the interaction with reactive @entity1039 groups in the stationary phase. In order to avoid these problems there are four basic strategies: (i) ionic pair reagents, (ii) deactivated @entity3440 columns, (iii) polymeric based columns and (iv) @entity1039 masking agents. A validation protocol was followed to develop the analytical method, using a Spherisorb ODS (250 x 4.6 mm i.d.) analytical column, with a mobile phase of 95% aqueous phosphate buffer (pH 3.0) and 5% HPLC @entity1042 pumped isocratically at 1.3 ml/ @entity1009 ), with ultraviolet detection at 254 nm. The results showed a high reproducibility in retention time value, with R.S.D. of 2.37% for ACV and 0.32% for @entity2774 . The lowest concentration levels assayed, 0.15 microg/ml(-1) for @entity2774 and 1 microg/ml(-1) for ACV, showed good R.S.D. in the quantification parameter (peak area) 11.0% ( @entity2774 ) and 9.64% (ACV)
