Thin-layer chromatographic examination of the degradation of centbucridine in aqueous solutions.

Centbucridine (9-n-butylamino-1,2,3,4-tetrahydroacridine) is a new potent local anaesthetic. Its degradation in aqueous solutions has been investigated with the help of thin-layer chromatography. Apart from the degradation products 9-amino-1,2,3,4-tetrahydroacridine and 1,2,3,4-tetrahydroacridone, acridone was also found to be present. It is shown that the acridone is produced not through a dehydrogenation reaction but some other unknown pathway.

Microencapsulation of soluble pharmaceuticals.

A method to microencapsulate water-soluble and liquid-paraffin insoluble drugs into spherical, discrete and free-flowing particles of approximately 175 microns size with excellent yield has been described taking diethylcarbamazine citrate as a model drug. In this method a gelatin-drug dispersion at 50 degrees C is sprayed, using a simple apparatus designed in our laboratory, into chilled, dry liquid paraffin present in a china dish previously coated with a layer of hard paraffin and maintained at 5 degrees C. After allowing the droplets to gel at 5 degrees C for an hour, water was removed by freeze drying. Later liquid paraffin adhering to freeze-dried microcapsules was removed by washing with chilled, dry acetone. Various factors affecting the yield, size, shape and size distribution of microcapsules were optimized.