Analytical method development using central composite design for estimation of lamotrigine in lipid nanoformulation

Objective of this study was to develop and validate HPLC-UV method for detection of LTG in lipid nanoformulations. HPLC-UV method was developed according to ICH Q2(R1) guidelines. Central composite design was used effectively to optimize and study the effect of buffer strength, flow rate, pH of buffer and mobile phase composition on responses such as tailing factor, peak area, retention time and number of theoretical plates. The 30 mM ammonium formate buffer and acetonitrile (in the ratio 65:35 %v/v) was used as mobile phase in the study. The mobile phase was delivered at the flow rate of 1.0 mL/min. The detection of buffer was performed at 256 nm using UV detector. The drug entrapment of prepared formulation was also determined using developed HPLC method. Retention time of lamotrigine was found to be 3.844 min. The coefficient of determination (r²) value from linearity was found to be 0.9982. Percent relative standard deviation value of precision was found to be within the acceptable range. The estimated LOD and LOQ were found to be 9.07 ng/mL and 27.48 ng/mL, respectively. Drug entrapment of prepared lipid nanoformulation was found to be 73.44 ± 6.65%. The results conclude that the developed analytical method is simple, precise, sensitive, fast and reproducible. Applications of developed method for determination of drug entrapment in prepared lipid nanoformulation confirmed that the developed analytical method is suitable for estimation of lamotrigine in lipid nanoformulations.