Composition and Mechanism of Action

The tablet consists of a core containing mannitol (E421), povidone K-90, macrogol 400, microcrystalline cellulose, colloidal anhydrous silica, and magnesium stearate. The coating contains cellulose acetate, macrogol 400, hypromellose, lactose monohydrate, titanium dioxide (E171), and triacetin. The sustained release is achieved through a semi-permeable coating that gradually becomes more porous as the core dissolves.

Preparation of the Suspension

The tablets must be crushed. This process may be more difficult due to the coating. A possible method consists of coarsely crushing the tablets in a mortar, followed by grinding with an electric coffee grinder to finely pulverize the coating. It is recommended to sieve the powder mixture to remove any remaining coating residues.

Formulation

The literature describes a 75 mg/5 ml suspension. The following composition can be used for preparation:

• Venlafaxine: 1.5 g
• Sorbitol: 40 g
• Veegum: 1 g
• Xanthan gum: 100 mg
• Tween 80: 150 mg
• Sodium saccharin: 100 mg
• Mint water based on aqua conservans: up to 100 ml

Since the tablet core contains excipients that affect viscosity, the final viscosity is difficult to determine in advance. The addition of Veegum and xanthan gum may therefore be unnecessary. If the viscosity proves insufficient at the end of the preparation, additional thickening agent can still be added.