Clobetasol propionate 0.05% in Tetracycline mouthwash BP 5 (?) 200ml; How to prepare?

Normally BP is the abbreviation for British Pharmacopoeia. I do not have this at my disposal but have found a tetracycline oral rinse in the formulary of the Dutch pharmacists. For 100 g, the composition is as follows:

tetracycline HCl 5g
after citrate 6.5 g
contrac. Hydroxybenzoate solution 1g
sorbitol syrup not crystal. 65.5 g
tragacanth 500mg
freshly cooked cooled off purified water 40g

Preparation

1. Mix in Rmortier clobetasolpropionate, tragacant and after citrate; add Conc hydroxybenzoate opl. and mix; add sorbitol syrup and mix to homogenous.
2. los tetracycline. HCl into water and add this solution slowly to the contents of the mortar under constant stirring