How to align custom UINavigationBar title (UILabel )in middle (iOS)

I am using following code to align 2 strings in UINavigationBar centre .

for ex:

         <Back     John Kelly Maria
                       23/F

I need these kind of middle aligned text in UINavigationbar but what jam now getting is all the text aligned in right side of UINavigationBar . something like this

      <Back                  John Kelly Maria   
                                  23/F

Please help..me . this is my code

 UIView *titleView = [[UIView alloc] initWithFrame:CGRectMake(0,0,320,50)];

    UIFont * customFont = [UIFont fontWithName:@"Helvetica Neue" size:19]; //custom font
    NSString * text =title;
    UILabel *patientNameLabel;
    if([title length]>15){
        patientNameLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, 0,320,30)];
    }else{
        patientNameLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, 0,320,30)];

    }
    patientNameLabel.text = text;
    patientNameLabel.font = customFont;
    patientNameLabel.numberOfLines = 0;
    patientNameLabel.textAlignment=NSTextAlignmentCenter;
    patientNameLabel.minimumScaleFactor = 10.0f/12.0f;
    patientNameLabel.clipsToBounds = YES;
    patientNameLabel.backgroundColor = [UIColor clearColor];
    patientNameLabel.textColor = [UIColor blackColor];
    patientNameLabel.autoresizingMask = UIViewAutoresizingFlexibleHeight;
    NSString *subTitle =subTitleText;
    UIFont * customFont1 = [UIFont fontWithName:@"Helvetica Neue" size:14]; //custom font

    UILabel *subTitleLabel = [[UILabel alloc]initWithFrame:CGRectMake(0,25,320,20)];
    subTitleLabel.textAlignment = NSTextAlignmentCenter;

    subTitleLabel.text = subTitle;
    subTitleLabel.font = customFont1;
     subTitleLabel.textAlignment=NSTextAlignmentCenter;
    subTitleLabel.numberOfLines = 1;

    subTitleLabel.adjustsFontSizeToFitWidth = YES;
    subTitleLabel.minimumScaleFactor = 10.0f/12.0f;
    subTitleLabel.clipsToBounds = YES;
    subTitleLabel.backgroundColor = [UIColor clearColor];
    subTitleLabel.textColor = [UIColor blackColor];
    [titleView addSubview:patientNameLabel];
    [titleView addSubview:subTitleLabel];