The present invention provides pharmaceutical formulation for thyroid hormones which allow safe and stable administration by mouth within the ambit of the narrow therapeutic index prescribed in the case of thyroid dysfunctions, as well as procedures for obtaining . A pharmaceutical composition for use in the treatment of obesity is also disclosed. Accordingly, a driving efficiency of the piezoelectric motor can be improved. The gear changing apparatus permits the user to adjust the carriage position with a single handed operation. The frequency response of the filter may comprise the substantial inverse of the frequency response of the microphone to provide a flat response. The invention finds particular application to a spare tire, but those skilled in the art will appreciate the broader benefits of such a structure when used with a winch assembly for other uses such as a boat winch for a trailer or any analogous use wherein it is desirable to secure a load in the raised or stored position.