Analysis of gemcitabine liposome injection by HPLC with evaporative light scattering detection

High-Performance Liquid Chromatography Coupled with Tandem Mass Spectrometry Method for the Identification and Quantification of Lipids in Liposomes

Liposomes are spherical, closed vesicles consisting of at least one lipid bilayer with a water chamber and are widely used to encapsulate bioactive molecules. Lipid membranes, composed of different types of lipids or lipophilic components, determine whether liposomes can achieve the desired purpose and determine the overall quality of liposomes. Thus, the quantification of lipid components and encapsulated molecules is essential to characterize and control the quality of liposomes. Moreover, multicomponent simultaneous determination is the preferred method for lipid component analysis in liposomes. Therefore, the present work describes an analytical methodology for the simultaneous determination of commonly used lipids in liposome formulations, using h igh-performance liquid chromatography coupled with a tandem mass spectrometry (MS) detector (HPLC-MS/MS). HPLC-MS/MS consists of a rapid and highly efficient chromatographic separation of the liposomal components with a C18 column and the subsequent detection of the ingredients through an MS detector, along with an accurate mass fragmentation pattern. The analytical process mainly includes lipid extraction, solution preparation, the optimization of chromatographic conditions, and method validation. We hope this analytical methodology is valuable and efficient and can be applied to the analysis of multiple types of lipids in liposomes, such as raw material quality analysis, formulation study, overall quality control, etc.

A Reliable HPLC-ELSD Method for Determination of Cholesterol, Phosphatidylcholine, Lysophosphatidylcholine Content and the Stability of a Liposomal Formulation

Background:

Liposomes continue to play an important role in drug delivery research due to their ability to improve transport and targeting of a wide range of active molecules. Analysis of liposomal components is a key point in the characterization and evaluation of formulation stability. The aim of this work was to develop and validate an HPLC-ELSD method for the characterization and quality control of liposomes.

Methods:

HPLC-ELSD method was validated by assessing selectivity, linearity, precision, accuracy, limit of detection and quantitation. The mobile phase consisted of a 0.1% (v/v) of trifluoroacetic acid (TFA) and methanol in gradient elution. Initial rate was 20:80 (0.1% TFA: methanol), with a ramp reaching 100% methanol. HPLC-MS/MS was used to confirm the presence of the fatty acid mixture in the analyzed lipids, as well as sub-products generated under pre-determined conditions in the stability study.

Results:

A HPLC-ELSD method has been developed to detect and measure cholesterol, phosphatidylcholine and lysophosphatidylcholine. High specificity, sensitivity and linearity within the predetermined range for all the compounds analyzed (R2>0.99) were obtained. Accuracy and precision results for all the compounds were within the acceptance limit of ≤5% and 90-110%, respectively. Mass spectrometry results showed complementary information about the phospholipid composition to evaluate the degree of degradation of liposomes over different storage conditions.

Conclusion:

The method was successfully applied as a quality control tool for the analysis of a wide range of lipids, present in liposomal formulations. HPLC-MS/MS was used to ensure complete elucidation of the lipid components and the detected lyso-forms.

Stability-indicating HPLC determination of gemcitabine in pharmaceutical formulations

A simple, sensitive, inexpensive, and rapid stability indicating high performance liquid chromatographic method has been developed for determination of gemcitabine in injectable dosage forms using theophylline as internal standard. Chromatographic separation was achieved on a Phenomenex Luna C-18 column (250 mm × 4.6 mm; 5μ) with a mobile phase consisting of 90% water and 10% acetonitrile (pH 7.00 ± 0.05). The signals of gemcitabine and theophylline were recorded at 275 nm. Calibration curves were linear in the concentration range of 0.5–50 μg/mL. The correlation coefficient was 0.999 or higher. The limit of detection and limit of quantitation were 0.1498 and 0.4541 μg/mL, respectively. The inter- and intraday precision were less than 2%. Accuracy of the method ranged from 100.2% to 100.4%. Stability studies indicate that the drug was stable to sunlight and UV light. The drug gives 6 different hydrolytic products under alkaline stress and 3 in acidic condition. Aqueous and oxidative stress conditions also degrade the drug. Degradation was higher in the alkaline condition compared to other stress conditions. The robustness of the methods was evaluated using design of experiments. Validation reveals that the proposed method is specific, accurate, precise, reliable, robust, reproducible, and suitable for the quantitative analysis.