$enc = 'UTF-8';
            $word =  "РАЗРАБОТАТЬ";
            $word = preg_replace('/s+/', '', $word);
            $word = mb_convert_case($word, MB_CASE_TITLE, "UTF-8");
            $count = mb_strlen($word, $enc);
            $new_word = mb_substr($word, 0, ($count - 1), $enc);
            $new_word = $new_word . mb_strtoupper(mb_substr($word,($count - 1), 1, $enc), $enc);
            $randomLine = $new_word;

header('Content-Type: text/html; charset=utf-8');

AddDefaultCharset UTF-8

function mb_strrev($str){
    $r = '';
    for ($i = mb_strlen($str); $i>=0; $i--) {
        $r .= mb_substr($str, $i, 1);
    }
    return $r;
}

function mb_ucfirst($str) {
    $fc = mb_strtoupper(mb_substr($str, 0, 1));
    return $fc.mb_substr($str, 1);
}

$word =  "РАЗРАБОТАТЬ";
$result = mb_strrev(mb_ucfirst(mb_strrev(mb_ucfirst(mb_strtolower($word))))); // РазработатЬ

$word =  "РАЗРАБОТАТЬ";
$word = preg_replace('/s+/', '', $word);
$word = mb_strtolower($word);
$word[1] = mb_strtoupper($word[1]);
$word[mb_strlen($word)-1] = mb_strtoupper($word[mb_strlen($word)-1]);