try this code...
UIFont *yourFont = [UIFont fontWithName:@"Helvetica-BoldOblique"
size:[UIFont systemFontSize]];
lblTitle.font = yourFont;
you can use also another fontName for BoldItalik like.
Optima-BoldItalic,TimesNewRomanPS-BoldItalicMT,Baskerville-BoldItalic,HelveticaNeue-BoldItalic,etc...