A process and apparatus (invention) permitting the distribution of micro or submicro
liter or
gram (exceptionally small) quantities of liquids and powders, (hereafter materials) in patterns and quantities that are especially well-suited for ophthalmologic patient self-application of drugs to his own eye(s) with substantially no overdose. The invention is thus also highly beneficial in those many
topical drug applications where overdoses should be avoided. This is particularly applicable for the eye, where overdoses can have many deleterious medical consequences. Use of the invention permits exceptionally small doses of ophthalmologic drugs. Moreover, it also permits the
repeatability of the quantity size of the materials chosen for delivery. In the case of drugs, particularly opthomologic drugs, this means that the invention permits the repeated multiple distribution of the same chosen
drug / carrier quantity resulting in a uniform repeatable dosage. Variation of
dose from one application to another is very unacceptable. The preferred apparatus of the invention employs a venturi configuration inventively modified which uses gas under pressure to pump exceptionally small quantities of material from a reservoir for delivery. In especially preferred embodiments of the invention, said reservoir is pressurized by at least a quantity of gas at somewhat above atmospheric. prior to the removal of any material by pumping.