Objective: Formulation of injectable In situ forming implant (ISI) systems of lornoxicam for
dental and postoperative pain management to decrease dosing frequency and increase patient compliance.
Methods: Polymeric in situ implant solutions were prepared using different concentrations and inherent
viscosities of Poly-DL-lactide (PDL) or DL-lactide/glycolide copolymer (PDLG) using 22X4 factorial
experimental design. Nonpolymeric systems were prepared using different concentrations of lipids like
cetyl alcohol and stearyl alcohol and also sucrose acetate isobutyrate (SAIB) using 32 factorial experimental
design. In vitro release study, rheological measurement, syringeability assessment and effect of
γ-sterilization were used for evaluation of the prepared formulae. In vivo pharmacokinetic study of lornoxicam
from the most optimum formula was conducted in a rabbit model using HPLC analysis of
Results: Polymeric systems showed high burst release followed by very slow release rate over 72 hours.
Formula I 24 (containing SAIB 80% (w/w)) showed relatively low burst release followed by diffusion
controlled release pattern, low viscosity, Newtonian flow behavior and good syringeability. γ-
sterilization had no significant effect on the in vitro release and the physical nature of the most optimum
formula. In vivo study concluded that intramuscularly injected In situ implant formula I 24 showed prolonged
release pattern compared to the marketed product which was indicated by the increased Tmax and
the extended mean residence time.
Conclusion: Lornoxicam ISI systems could be promising as convenient injectable sustained release
delivery systems for dental and postoperative pain management.