The aim of this study is to enhance the dissolution rate of raloxifene hydrochloride and to prepare tablets by PEGylation. The high-molecular-weight polyethylene glycols, PEG 15 000 and PEG 35 000, were used for PEGylation of raloxifene hydrochloride, a water-insoluble BCS Class II drug. The PEG conjugates were prepared with PEGs in the weight ratios of (1:1), (1:2), and (1:3.5) by using the solvent evaporation technique and the kneading technique. The conjugates were analyzed by FTIR, XRD, and DSC and subjected to dissolution studies. FTIR analysis revealed the interaction of raloxifene HCl with PEG indicating the formation of a conjugate. RLX: PEG 35 000 (1:3.5)(KM) conjugate exhibited the highest dissolution rate of 99.12% at in vitro level among all the RLX: PEG 15 000 and RLX: PEG 35 000 conjugates. The tablets of raloxifene hydrochloride were prepared by using RLX: PEG 35 000 (1:3.5) by the direct compression technique and evaluated. The prepared tablets exhibited optimum drug release characteristics of 99.12% in 60 min and the physical characteristics such as hardness (4.5 kg/cm2), friability (less than 1%) and percent drug content (99.79 ± 0.62). The ideal drug release pattern from prepared tablets was indicated by T50 and T90 values as 29.5 and 42 min, respectively, from the dissolution data. Hence, the present studies indicated that the PEGylation of raloxifene HCl was a successful technique to enhance the dissolution rate of raloxifene HCl and to prepare its tablets.
Key words: Dissolution, FTIR, kneading technique, PEGylation, raloxifene hydrochloride, solvent evaporation, XRD.
