To do that you must specify a single page spread. Probably you should lock the orientation too.
For EPUB2, put this in your "com.apple.ibooks.display-options.xml":
Code:
<?xml version="1.0" encoding="UTF-8"?>
<display_options>
<platform name="*">
<option name="fixed-layout">true</option>
<option name="open-to-spread">false</option>
<option name="orientation-lock">landscape-only</option>
</platform>
</display_options>
For EPUB3:
Insert this in your .opf file (no need for the apple xml file anymore):
Code:
<meta property="rendition:layout">pre-paginated</meta>
<meta property="rendition:spread">none</meta>
<meta property="rendition:orientation">landscape</meta>