Improved pharmaceutical properties of surface modified bioactive plumbagin crystals

Plumbagin recrystallised by cold crystallisation technique using a variety of polar and non-polar solvents was investigated for pharmaceutical properties. Different solvents gave varying sized and shaped plumbagin. Powder X-ray diffraction, differential scanning calorimetery and fourier transform infrared spectroscopy too confirmed differing crystal habit. Platy crystals, the most significant forms, obtained from cyclohexane possessed small size (62.93 ± 3.74 μm), higher bulk density (0.108 ± 0.014 g/ml) and lower enthalpy of fusion (∆H 62.62 ± 3.67 J/g). These demonstrated approximately two-fold increase in saturation solubility (155.01 ± 3.86 μg/ml), higher Q5min (cumulative percentage dissolution in 5 min) and lower t65% (time required for 65% dissolution) owing to greater surface area. In-vivo anti-inflammatory study in Wistar rats demonstrated improvement in therapeutic efficacy of recrystallised plumbagin. In conclusion surface modification led to enhanced efficacy of plumbagin; an approach capable of improving the bioavailability and clinical efficacy of other poorly water soluble phytomedicine.