An orodispersible pharmaceutical composition for melatonin
The technology used to prepare orodispersible tablets usually involves direct compression. The main modifications have involved the components of the formulation and, as far as the device is concerned, the pressure exerted has been the main factor modified during tablet manufacture. When conducting this project four different doses of melatonin based on the dose/therapeutic response relationship have been used. The smallest quantities of active substance (3 and 5 mg) have been used to improve the quality of life of epileptic children treated with valproic acid; as an alternative prophylactic treatment for the prevention of migraine; for neurodevelopmental disability; in sleep disorders and in blind children.
The 10 and 60 mg doses have been developed to treat muscular dystrophy in children (a recessive hereditary dystrophy linked to the X chromosome that tends only to affect males).
Other melatonin presentations have also been developed by incorporating alpha-tocopherol acetate (10 IU) to formulations of this hormone for use in the treatment of children with Duchenne's disease in order to enhance the antioxidant effect of melatonin.
Finally, orodispersible tablets of melatonin (5 mg) and tryptophan (150 mg) (an essential amino acid in human nutrition) have also been developed. As hormone formation commences with uptake of the amino acid tryptophan from the blood stream, if the hormone and amino acid are administered jointly, in addition to other advantages resulting from this combination, melatonin synthesis and release of the neurotransmitter serotonin will be enhanced.
The technology used was direct compression using appropriate excipients, said excipients being carefully selected as not all excipients lead to tablets with suitable characteristics. In our case, in light of their intended use in children with various types of disorders, the tablets also had to be small, and we attempted to achieve this considering the active substances selected.
No orodispersible tablets with these characteristics, at the doses prepared and for paediatric use are currently marketed, thus meaning that they are novel in this field.
The pharmaceutical form selected for these presentations is orodispersible tablets in order to rapidly disperse our medicinal product in the oral cavity, thereby ensuring better absorption of the active substance and rapid onset of the effect. In addition, the target population for these preparations, namely paediatric patients, tends to more readily accept this form. Moreover, the components used are readily available on the pharmaceutical market and their safety has been clearly demonstrated. As regards the technique used, direct compression is one of the most widely used techniques and, once the appropriate excipients have been selected, in our case the pressure exerted by the punches in the tablet press was varied until tablets with a suitable hardness from a transport, friability and disintegration point of view were achieved. Their manufacture and reproducibility was satisfactory.