Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number NDC42291-0250-50 found under Doxycycline Hyclate by Avkare Inc. The National Stock Number assigned to this part is 6505000095063, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like NDC42291-0250-50.