PREPARATION OF NANOPARTICLES LOADED NASAL GEL OF MIRTAZAPINE FOR TREATMENT OF DEPRESSION

Mirtazapine is a representative of a new class of antidepressants. Mirtazapine is a white to creamy white crystalline powder which is slightly soluble in water. New antidepressant drugs, with less adverse effects than imipramine derivatives, have been developed; they selectively block both the serotonin transporter and the nor adrenaline (NA) transporter, (that is, mixed serotonin/nor adrenaline reuptake inhibitors, SNRIs, NaSSA e.g. mirtazapine. The pharmacological profile of mirtazapine is characterized by potent presynaptic 2-adrenergic antagonistic activity, 5-HT1 agonistic activity, and potent 5-HT2 and 5-HT3 antagonistic activities, as well as by a potent H1 antagonistic activity. The blockade of presynaptic 2-adrenergic receptors is considered as a possible mechanism for antidepressant activity of mirtazapine. The obtained mirtazapine nanoparticles formulations F1, F2, F3, F4, F5, F6 and F7 were evaluated for percentage yield, drug loading, particle size, surface morphology, viscosity, in vitro release rate studies. F4 shows maximum percentage yield of 98.54%, particle size of 50 nm. F4 were superficially spherical in shape with smooth surface. The viscosity of nasal gel was determined by using a Brookfield viscometer at different RPM i.e. (12,10,8,6,5) and it was concluded that the rate of shearing is directly proportional to shearing stress, which shows that the formulation is non-Newtonian in nature. When the rate of shear is increased viscosity decreases that prove that the formulation is shear thinning pseudo-plastic in nature. The in vitro dissolution study revealed that as we increase polymer concentration, drug release from nanoparticles and vice versa. So we have optimized maximum concentration of polymer and drug as in case of formulation F4 50% of drug get released in 12 hrs. The drug release was found to be 98.54% for F4 formulation in 24 hrs.