Ay, mahirap yan, mama! Better check with your pedia muna bago mag-switch from drops to syrup, baka different ang dosage or ingredients, at gusto mo sigurado na safe talaga para sa 23-month-old mo. I know it's frustrating kapag out of stock, pero mas peace of mind kung doctor-approved na, di ba? Hope makakita kayo ng drops ulit or makapag-consult agad!