Azathioprine Preparation

5.1 MATERIAL USED
Azathioprine was obtained as a gift sample from M/s Psycorem Pharmaceuticals Ltd. (Ludhiana, India); Carbopol 934 was purchased from Sunchem (India), Tween 20 and Span 20, Methyl and Propyl paraben, Light liquid paraffin, Propylene glycol, Triethanolamine (TEA), and Ethyl alcohol were purchased from M/s Central Drug House Pvt. Ltd ( New Delhi, India). Doubled distilled water was used throughout the study.
5.2 METHOD OF PREPARATION OF AZATHIOPRINE EMULGEL
5.2.1 Preparation of Emulsion
The oil phase of the emulsion was prepared by dissolving 0.9 mL of Span 20 in 5 ml of Light liquid paraffin while the aqueous phase was prepared by dissolving 0.6 ml of Tween 20 in 25 ml of purified water. 30 mg of methyl paraben and 10 mg of

5.2.3 Incorporation of Emulsion into Gel base
For preparation of emulgel, the obtained emulsion was mixed with gel in 1:1 ratio with gentle stirring. During mixing of emulgel, glutaraaldehyde was mixed to obtain the emulgel (Figure 5.1). Fig 5.1: Flow chart for preparation of Emulgel
5.3 OPTIMIZATION OF AZATHIOPRINE LOADED EMULGEL
Various process variables like gelling agent concentration, oil and emulsifier concentration which could affect the preparation and properties of emulgel were identified and studied.
5.3.1 Effect of varying Gelling Agent concentration
Emulgel was prepared using varying concentration of gelling agent via 0.5, 1.0, 1.5 and 2.0 gm while keeping other variables constant by method reported in section. The effect of varying gelling agent concentration on viscosity and drug content are reported in Table 5.1 and shown in Figure 5.2 and 5.3 respectively.
Table 5.1: Effect of varying Gelling Agent concentration on viscosity and Drug content of Emulgel
Batch Code Gelling agent concentration (gm) Viscosity (cp) % Drug