include 'simple_html_dom.php';
$products = simplexml_load_file('http://www.optnow.ru/opt.xml');
foreach($products->shop->offers->offer as $product) {
    $productUrls[] = $product->url;
}

foreach($productUrls as $productUrl) {
    $curl_handle = curl_init();
    curl_setopt($curl_handle, CURLOPT_URL, $productUrl);
    curl_setopt($curl_handle, CURLOPT_CONNECTTIMEOUT, 2);
    curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
    $productDesc = curl_exec($curl_handle);
    curl_close($curl_handle);
    echo '<pre>';
    var_dump(str_get_html($productDesc)->find('.description  div div p'));
    echo '</pre>';
}