Prunus Cerasoide Lab

2. Experimental
2.1. Materials The gum Prunus cerasoides D. Don was collected from Aizawl, Mizoram, India (during the month of May-July). Diclofenac sodium was obtained from Kowsik Pharmaceuticals, Chennai, India. Calcium chloride and sodium alginate were purchased from SD Fine Chemicals Limited, Mumbai, India. All the chemicals and reagents used were of analytical grade.
2.2. Purification of Prunus cerasoides gum The purification of the gum was carried out as previously described by our group [20]. Briefly, the crude gum powder was boiled with 80% ethanol solution to deactivate enzymes and dissolve out low molecular weight carbohydrates with coloring matters. Thereafter, it was dispensed in deionized water and gently stirred overnight

Initially, PC gum was dissolved in distilled water and boiled for 10 min, cooled and stirred for 24 h at 400 rpm in a magnetic stirrer. Vacuum filtration was then carried out with a Buchner funnel. The gum solution was homogenized using a homogenizer (IKA, Germany) at 15000 rpm for 2 min. The homogenized gum solution was then mixed with SA and DS. The final dispersion was added drop wise using a syringe fitted with 24 gauge hypodermic needle into 10 % calcium chloride solution and stirred at 300 rpm for 30 min with a magnetic stirrer to complete the curing reaction, resulting in the formation of beads. The mixture was then filtered and the beads were washed thrice with distilled water. The obtained beads were air dried for two days and stored in a desiccator for further

Differential scanning calorimetry (DSC) The DSC curves of PC, DS, PC-SA and [F5] were recorded using a DSC Pyris 6 instrument (Perkin Elmer, USA). Briefly, 2-4 mg of the sample was taken in a 50 μL aluminium pan in a hermetically sealed condition. The measurements were done in the atmosphere of nitrogen (20 mL/min), and the temperature was maintained from 25 °C to 400 °C at a heating rate of 10 °C/min. Platinum crucible with alpha alumina powder was used as a reference.
2.8. Thermo gravimetric analysis (TGA) TGA of PC, PC-SA, DS and [F5] were recorded using a TGA 4000 (Perkin Elmer, USA). Samples were heated from 35 °C to 950 °C, at a heating rate of 20° C/min, under nitrogen atmosphere (flow rate 20 mL/min), in open aluminium pans containing about 5 mg of the beads.
2.9. Evaluation of Swelling behavior The swelling behavior of [F1] and [F2-F6] beads were tested using a wire basket and placed in pH 1.2 0.1 N HCl and pH 7.4 phosphate buffer solution at 37 °C. At particular time intervals, the swollen beads were removed and weighed.
The swelling ratio was calculated using the following