336 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS containing either propellant 11 or 114, the dispenser was warmed and kept at 50 ø C for 15 minutes, amidst constant shaking, to obtain maximum solution. No warming took place with System A (propel!ant 12), but where necessary, the dispensers were shaken intermittently tor 1 hour. All filled dispensers were allowed to stand for 1 hour at 20 ø C before being examined for solubility. The results obtained are detailed in Table 2. Dispensers filled with each variable were re-examined after 6 weeks' storage at both 20 ø C and 0 ø C, in the following manner. Dispensers stored at 20 ø C (1) Visible assessment of solubility (2) Assessment of sprayability, and observation of valve blockage, if any. Dispensers stored at 0 ø C (1) Visible assessment of solubility at 0 ø C, and after being allowed to stand for 24 hours at 20 ø C. (2) Assessment of sprayability, and observation of possible valve block- age, at 0 ø C, and after being allowed to stand for 24 hours at 20 ø C. Containers and valves Plastic.coated glass containers were utilised for all tests. For systems A-H, Aerosol Research valves AR74 with SF64 (0.02") actuators were employed, and for system I, Precision valves [J18 stem, standard housing (0.08#)] with reverse taper break-up spray actuators. There was no definite preference for the Aerosol Research valve, but Precision valves suitable for glass containers were not available to us at the time when these experiments were started. RESULTS Table 2. Solubility of 10 lanolin products after 1 hour at 20 ø C Lanolin Propellant systems products A B C D E F G H I Total i ii iii iv v vi vii viii ix x 4 3 6 4 3 4 3 3 4 5 3 6 3 3 3 3 2 2 4 1 6 I 1 3 2 1 3 5 2 6 2 1 2 4 2 2 4 I 6 2 1 3 2 1 2 2 2 6 1 2 2 2 1 1 6 2 6 2 1 1 2 1 1 1 2 6 1 2 2 1 1 1 4 4 6 2 2 4 4 2 4 6 4 6 2 2 3 4 4 4 Total 41 24 60 20 19 27 27 18 24 34 30 22 26 22 19 22 17 32 35 Key 1 = soluble--no precipitate 2 = soluble, with negligible precipitate (visible only on close scrutiny) 3 = soluble, with slight precipitate (readily seen on inverting bottle) 4 = partially soluble, with either a dense precipitate or an insoluble liquid layer floating on the surface 5 = partially soluble with dense precipitate and insoluble waxes 6 = totally insoluble a = agglomeration of precipitate

LANOLIN DERIVATIVES FOR PRESSURIZED FORMULATIONS 337