Title : Stability studies on the formulations of inclusion complex of tenoxicam in SBE7 ? cyclodextrin and beta cyclodextrin
The present study was carried out to evaluate the usefulness of sulfobutyl ether β-cyclodextrin (SBE7-β-CD), [captisol], in increasing the dissolution rate of tenoxicam. The efficacy of captisol in increasing the dissolution when compared with beta cyclodextrin is investigated. The approach employed to prepare the inclusion complexes of the drug with captisol and beta cyclodextrin is by freeze-drying and kneading methods. The phase solubility studies indicated that a 1:1 M complex was formed between tenoxicam and the two complexing agents. The complex in captisol showed a much higher dissolution rate compared to the complex prepared in beta cyclodextrin and pure drug tenoxicam. In between the kneaded and freeze-dried complexes, the freeze-dried complex showed higher dissolution efficiency and rate. At the end of 30 minutes, the pure drug showed less than 20% dissolution, the kneaded and freeze dried complexes exhibited 75% and 94% dissolution respectively. The inclusion complexes were evaluated by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The drug is found to exist in amorphous state in the complexes. The efficacy of hydrophilic polymers, gelucire and hydroxypropyl cellulose in stabilizing the high dissolving amorphous forms of tenoxicam in the tablet formulations was studied and the findings of the investigation suggested that the hydrophilic polymers were able to offer protection in preventing the transformation of the amorphous drug during compression and storage. It is observed that after storage, there is a significant decrease in the dissolution of drug in formulations prepared by beta cyclodextrin whereas such an adverse effect is not seen in tablets that had complexes made of captiosl. The post compression properties of the tablets formulated were evaluated. The hardness of tablets of all formulations was in the range of 2.71 to 3.27 kg/cm2. The friability of tablets of all formulations was less than 1 %. The tablet formulations in all the prepared batches contained tenoxicam within 100 ± 5% of expected content. It can be concluded from the results of the present study that careful formulation is essential to stabilize the high dissolving forms of drugs to retain their physical stability and high dissolution characteristics.
Audience take away:
• The audience will be able to use the results and findings of the study in developing fast dissolving dosage forms and take appropriate measures in stabilizing the dosage forms.
• The methods employed will help in exploring newer hydrophilic polymers in evaluating their utility in stabilizing the fast dissolving forms.
• The investigators in this field will be able to design new projects and expand the studies into carrying out studies on various therapeutic categories of drugs.
• A more rationalistic and optimal tablet formulation can be developed and the findings of the study should help in thoroughly carrying out evaluations of the drug and various excipients used in the tablet dosage forms.