ABSTRACT
A method for the determination of theophylline and promethazine in suppositories is proposed which allows the determination of both components in a single suppositorium. The ingredients were extracted by hot water and addition of a little bit of sulfuric acid. Theophylline is determined potentiometrically without separation of promethazine by titrating the acid which is set free after addition of silver nitrate. Promethazine is separated by ether in alkaline medium, reextracted in HCl (0,1 mol/l) and determined colorimetrically. The precision of both methods is good. The results of the determination in the suppositories are given.
Subject(s)
Aminophylline/analysis , Promethazine/analysis , Chemical Phenomena , Chemistry , Colorimetry , Silver Nitrate , SuppositoriesSubject(s)
Patient Compliance , Drug Therapy , Humans , Pharmaceutical Preparations/blood , Research DesignABSTRACT
The presence of pores in plastic membranes is detected by the permeability of the latter to electrolytes in the electric field. The plastics are not damaged by the electric field intensities applied. Lithium chloride and crystal violet are employed as electrolytes. In this way, pore-size differentiation becomes faesible. A dialyzing membrane is used for the purpose of comparison. The electrical resistance of the membrane permits conclusions to the amount of its porosity. On using crystal violet, the migration through the pores can be followed visually or colorimetrically.
