The purpose of this research was to develop and evaluate buccal mucoadhesive controlled release tablets of lercanidipine hydrochloride using polyethylene oxide and different viscosity grades of hydroxypropyl methylcellulose individually and in combination. Effect of polymer type, proportion and combination was studied on the drug release rate, release mechanism and mucoadhesive strength of the prepared formulations. Buccal mucoadhesive tablets were made by direct compression and were characterized for content uniformity, weight variation, friability, surface pH, thickness and mechanism of release. In order to estimate the relative enhancement in bioavailability one optimized formulation was evaluated in rabbits. Further, placebo tablets were also evaluated for acceptability in human subjects. Results indicated acceptable physical characteristics of designed tablets with good content uniformity and minimum weight variation. Drug release and mucoadhesive strength were found to depend upon polymer type, proportion and viscosity. The formulations prepared using poly ethylene oxide gave maximum mucoadhesion. The release mechanism of most formulations was found to be of anomalous non-Fickian type. In vivo studies of selected formulation in rabbits demonstrated significant enhancement in bioavailability of lercanidipine hydrochloride relative to orally administered drug. Moreover, in human acceptability studies of placebo formulations, the designed tablets adhered well to the buccal mucosa for more than 4 h without causing any discomfort. It may be concluded that the designed buccoadhesive controlled release tablets have the potential to overcome the disadvantage of poor and erratic oral bioavailability associated with the presently marketed formulations of lercanidipine hydrochloride.

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A bioanalytical method was developed and validated using High Performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) technique for the determination of Rivaroxaban in human plasma. The samples were extracted using solid-phase extraction (SPE) technique wherein Rivaroxaban D4 has been used as the internal standard. The use of isocratic Liquid chromatography (LC) method has enabled to achieve 2.0 minutes along with their respective internal standard using a Phenomenex Gemini C18, 50*4.6mm, 5µ column. The developed method was specific and sensitive having no interfering peaks in the drug free plasma. The method was validated for a linear range of 2.00-500.93 ng/mL for Rivaroxaban with a correlation coefficient e" 0.99. The limit of detection (LOD) of 2 ng/mL for Rivaroxaban a signal-to noise (S/N) >10 was achieved, Electrospray ionization source in positive mode was used for the detections of Rivaroxaban and IS. Precursor to product ion transition of m/z 436.20 > 144.80 for rivaroxaban and m/z 440.20 > 144.70 for IS were used in multiple reaction monitoring mode. Intra-run precision (%CV) ranged from 3.8% to 0.9% for Rivaroxaban. Inter-run accuracy(%Bias) ranged from -3.1% to -1.9% for Rivaroxaban .The overall recoveries for Rivaroxaban, Rivaroxaban D4 were found to be >96%. Rivaroxaban was found to be stable at various temperatures and for about 5 freeze-thaw cycles and reconstituted samples were stable up to 72 hours post to extraction. The developed and validated method was found to be precise, reproducible and a high throughput of analyzing more than 400 samples per day could be achieved with a shorter run time of 2.0 minutes. The developed method is useful to measuring Rivaroxaban plasmatic concentrations in pharmacokinetics studies and in therapeutic drug monitoring.