pre·pa·ra·to·ry 
/prɪˈperəˌtori, Brit prɪˈpærətri/ adjective
always used before a noun /prɪˈperəˌtori, Brit prɪˈpærətri/ adjective : used or done to prepare for something
▪ The new employees have begun preparatory [=introductory] training. ▪ There is a lot of preparatory work involved in teaching.
▪ The new employees have begun preparatory [=introductory] training. ▪ There is a lot of preparatory work involved in teaching.
preparatory to
formal : as a way of becoming ready for (something) : in preparation for (something)
▪ Preparatory to the job interview, I researched the company.
▪ Preparatory to the job interview, I researched the company.
