Preparation and Solid State Characterization of Paclitaxel Cocrystals

Objective of the present study is to prepare a co crystal of paclitaxel with improved solubility and bio availability. Paclitaxel is poorly water soluble and low bioavailable drug, this low oral bioavailability is mainly due to poor aqueous solubility and by the high affinity of paclitaxel for P-gp This research work foresees the advantages of co-crystal technology towards the enhancement of paclitaxel solubility and there by its bioavailability. Two sets of coformers were selected based on their chemical nature, using suitable cocrystal preparation techniques various batches of paclitaxel cocrystals were prepared and subjected to solid state characterization to determine the crystal structure of the cocrystals, as this can provide significant new insights into how the drug and coformer interact, and thereby provide an excellent crystal engineering guide to new cocrystals, potentially with improved properties. Instruments like Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry, X-ray powder diffraction will be used to determine their stability, and any phase transformations (including decomposition) which they might undergo as a function of temperature. Principle involved in the formation of cocrystal is hydrogen bonding between C=O and N-H group of drug and COOH groups of coformers, which is confirmed by FTIR data and DSC experiments were carried out to study the melting point and heat of enthalpy of the cocrystals. Results clearly shows that the melting point of the cocrystals were increased which confirms the formation of cocrystals. The drug and formation of cocrystals are explained by the X-ray powder diffraction patterns. The PXRD patterns of pure drug showed sharp well defined peaks(spectrum attached) and cocrystals PXRD patterns shows that there is a significant differences in the entire diffraction pattern, changes in peak locations with respect to pure drug indicates change in arrangement of molecules, hence conforms the development of new crystalline phase.