Modification of Physicochemical Properties of Active Pharmaceutical Ingredient by Pharmaceutical Co-Crystals

The oral drug delivery is widely used and accepted routes of administration, but it fails to provide the therapeutic effectiveness of drugs due to low solubility, poor compression and oral bioavailability. Crystal engineering is the branch where the modification of API is of great importance. Co-crystallization of API using a co-former is a hopeful and emerging approach to improve the performance of pharmaceuticals, such as micromeritic properties, solubility, dissolution profile, pharmacokinetics and stability. Pharmaceutical co-crystals are multicomponent systems in which one component is an active pharmaceutical ingredient and the others are pharmaceutically acceptable ingredients that are of GRAS category. In multidrug co-crystals one drug acts as API and other drug acts as coformer. This chapter illustrates the guidance for more efficient design and manufacture of pharmaceutical co-crystals with the desired physicochemical properties and applications

CO-CRYSTALS OF CARVEDILOL: PREPARATION, CHARACTERIZATION AND EVALUATION: CO-CRYSTALS OF CARVEDILOL

Carvedilol an antihypertensive drug, exhibit poor solubility and dissolution rate. Hence an attempt has been made to prepare the Co-crystals of Carvedilol to increase the solubility and dissolution rate by solvent evaporation method using coformer such as succinic acid, fumaric acid and oxalic acid. The prepared Co-crystals were evaluated for  solubility, dissolution rate and micromeritic properties. The Co-crystals were characterized by scanning electronic Microscopy (SEM), FT-Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and X-ray Diffractometry (XRD). The CAR-SA Co-crystal, CAR-FA Co-crystals and CAR-OA Co-crystals showed increased in solubility and dissolution rate compared to pure Carvedilol. The Co-crystals formed with coformer have showed improved micromeritic properties. SEM clearly showed the formation of new solid phase with the coformer. The FT-IR spectra indicate the shifting of characteristic peak in the Co-crystals but does not showed any interaction between the coformer used. DSC data showed the change in the endotherm with the melting points of Co-crystals. XRD spectra indicate the notified difference in the 2θ and the intensity of the peaks. Hence the Co-crystal formation could be helpful to improve the solubility, dissolution and micromeritic properties of Carvedilol