Preformulation characterization of Thiocolchicoside

Introduction: Thiocolchicoside is semi-synthetic sulfur derivative of colchicine, which is a naturally occurring glucoside in the Colchicine plant. It is potent muscle relaxant with anti-inflammatory and analgesic activities. Thiocolchicoside is biopharmaceutical classification system (BCS-III) drug.

Aim & objectives: The present research work was aimed to study the pre-formulation parameters of Thiocolchicoside to develop suitable and stable subcutaneous formulation. Objective of the study was to develop promising subcutaneous dosage form to overcome the existing limitations of the current route of delivery and to prepare a way by observing the physical and chemical properties of drug substance for transforming into drug product in such a way that drug product can be administered in a right way.

Methods: Organoleptic characteristics of Thiocolchicoside were analyzed. Centrifugation method was used to analyze the solubility. Partition coefficient was determined. Melting point was analyzed by capillary method. Infra red spectroscopy was performed. X-ray diffraction was conducted to confirm the inside arrangement. Nature of peak was analyzed through differential scanning calorimetry. Calibration plot of drug with HPLC with acetonitrile: water (70:30) was carried out for LOD and LOQ determination.

Results: Thiocolchicoside found with pale yellow color and mild odour. Solubility found 12.65 mg/ml. Partition coefficient found 0.378. Melting point found in the range of 163-169.33 º C. IR spectra had given peaks for primary and secondary amide at 1603 cm^-1& 3291.2 cm^-1, ketone moiety of tropane nucleus at 1649.7 cm^-1, thioether at 2360.8 cm^-1 and hydroxyl group at 3299.1 cm^-1. Single exothermic peak observed at 161.83 º C temperature with differential scanning calorimetry. Drug was subjected for X-ray diffraction analysis from temperature range at 10 º C to 90 º C, 79.4% crystallinity & 20.6% amorphousness of drug was found. Calibration plot with HPLC has given regression coefficient of 0.998. Mean retention time for peaks was observed 2.655 minutes. LOD was 1.092µg/ml and LOQ was 3.311µg/ml.

Conclusion: Drug found stable under all analyzed parameters. The target dosage form with Thiocolchicoside is promising to overcome the existed limitations with current route of delivery.