Zolmitriptan Case Study

The dissolution of the drug in different liquisolid formulations was performed in 500 ml simulated salivary fluid (phosphate buffer pH 6.8) maintained at 37 ± 0.5 ºC using the USP dissolution tester apparatus II, at a rotation speed of 50 rpm. Aliquots from the dissolution medium were withdrawn at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12.5, 15, 20, 25 and 30 minutes time intervals. The samples were changed with fresh dissolution medium of same amount to maintain a constant volume in the vessels. Samples were filtered with 0.45 millipore filter and drug content were analysed spectrophotometrically at λ max(78,79). The simulated salivary fluids used was composed of NaCl (8g/L), KH2PO4 (0.19g/L) and Na2HPO4 (2.38g/L). Food and drug administration (FDA)
This formulation was denoted as direct compressed tablets (DCT) and each tablet contains 2.5 mg Zolmitriptan, 221.2mg of Avicel (PH-102), 6.31mg of Aerosil200, 12.5mg of crospovidone and 2.5mg of magnesium stearate, sodium saccharin and vanillin, respectively. Zolmitriptan conventional ODTs were produced by mixing the drug with Avicel (PH-102) and Aerosil 200 (ratio of Avicel (PH-102) to Aerosil 200 was set at 35:1) for a period of 10 min. The blend was mixed with crospovidone (as disintegrating agent) and other additives for 10 min then magnesium stearate was added and mixed for 2 minutes. After that, the final blend was directly compressed using a single punch tablet machine of 8mm die
2.3.7.2 Fourier Transforms Infrared Spectroscopy (FTIR).
Compatibility studies of pure Zolmitriptan and excipients were performed via using fourier transformed infrared spectrophotometer (Shimadzu, Japan) in the range of 400-4000/cm-1 by using KBr disc method. A base line correction was made using dried potassium bromide KBr and then the spectrum of the pure Zolmitriptan, Avicel (PH-102), physical mixture of Zolmitriptan : Avicel (PH-102) (1:1) and liquisolid system were obtained(84).
2.3.7.3 X-Ray Diffractometery (XRD). It is important to study the polymorphic changes of the drug as these changes may influence dissolution rate and bioavailability of the drug. X-ray powder diffraction measurements were performed on samples utilizing a diffractometer. The results were recorded over a range of 0 –50° (2θ) using the Xe-filled detector and Cu-target X-ray tube. For characterization of crystalline state, XRD patterns for pure Zolmitriptan, Avicel (PH-102), physical mixture of Zolmitriptan:Avicel (PH-102) (1:1) and liquisolid systems formula were