**7. Formulation of drug loaded bio-nanoparticulate system**

The different formulations of bio-nanosuspension were prepared by using different drug-biopolymer ratio and drug-standard polymer ratio. The bionanosuspension was prepared by sonication of the mixture of drug and biopolymer along with other excipients like polyvinyl alcohol as suspending agent, sodium benzoate as the preservative, purified water, and dextrose as nanosizent [9, 13, 67, 68]. The lamotrigine, biopolymer, and other excipients were accurately weighed and triturated with the addition of the double-distilled water. This mixture was sonicated for 3 cycles. Then 0.5 ml of 0.5% polyvinyl alcohol was added during sonication. The volume of the formulations was made up to 10 ml with double distilled water having sodium benzoate 0.1–0.5%). Add dextrose if necessary as a nanosizing agent and allowed for sonication for 15 cycles at 4000 rpm. After sonication, the bionanosuspension was refrigerated for two days [11, 41, 69, 70]. If no settlement is there then it means the formulation is optimized. If the settlement is there, then 0.5 ml of 0.5% polyvinyl alcohol was again added and allowed for sonication for 10 cycles

and refrigerated for 48 hours. The different formulations were prepared and after optimization, according to stability, the formulations were prepared. In the same way, the nanosuspension was also prepared by using lamotrigine with a standard polymer like hydroxypropyl methylcellulose [3, 4, 13].
