*Article* **Biocompatibility and Pharmacological Effects of Innovative Systems for Prolonged Drug Release Containing Dexketoprofen in Rats**

**Liliana Mititelu-Tartau 1,†, Maria Bogdan 2,\*, Daniela Angelica Pricop 3,\*, Beatrice Rozalina Buca 1,† , Loredana Hilitanu 1,†, Ana-Maria Pauna 1,†, Lorena Anda Dijmarescu 4,† and Eliza Gratiela Popa <sup>5</sup>**


**Abstract:** The present study reports on the in vivo biocompatibility investigation and evaluation of the effects of liposomes containing dexketoprofen in somatic sensitivity in rats. Method: The liposomes were prepared by entrapping dexketoprofen in vesicular systems stabilized with chitosan. The in vivo biocompatibility was evaluated after oral administration in white Wistar rats: Group I (DW): distilled water 0.3 mL/100 g body weight; Group II (DEX): dexketoprofen 10 mg/kg body weight (kbw); Group III (nano-DEX): liposomes containing dexketoprofen 10 mg/kbw. Blood samples were collected from caudal lateral vein one day and seven days after the substance administration, to assess the eventual hematological, biochemical, and immunological changes. The investigation of somatic pain reactivity was performed using the hot plate test, to count the latency time response evoked by the thermal paws' noxious stimulation. Results: Original liposomes entrapping dexketoprofen, with mean size of 680 nm and good stability, were designed. Laboratory analysis indicated no substantial variances between the three treated groups. The treatment with liposomes containing dexketoprofen resulted in a prolongation of the latency time response, statistically significant in the interval between 90 min and 10 h, in the hot plate test. Conclusions: The use of liposomes with dexketoprofen proved a good in vivo biocompatibility in rats and prolonged analgesic effects in the hot plate test.

**Keywords:** liposomes; dexketoprofen; biocompatibility; hot plate test; rats
