Enhanced targeting efficiency of PLGA microspheres loaded with Lornoxicam for intra-articular administration

Figures & data

Figure 1.  Size distribution of Lnxc-PLGA-MS. A: undried microspheres; B: freeze dried microspheres; C: vacuum dried microspheres

Figure 2.  SEM microphotos of Lnxc-PLGA-MS A,B: freeze-dried microspheres; C, D vacuum-dried microspheres

Figure 3.  The DSC results of Lnxc loaded PLGA microspheres (A) Lnxc loaded microspheres(freeze drying without mannitol), (B) Lnxc loaded microspheres (freeze drying with mannitol), (C) physical mixture(with mannitol), (D) physical mixture(without mannitol), (E) mannitol, (F) PLGA, (G) gelatin, (H) Lnxc.

Figure 4.  in.vitro release of Lnxc-PLGA-MS (mean ± SD, n = 3)

Table 1.  The regression equation of in vitro release of Lnxc and Lnxc-PLGA-MS

	Model	Equation	r
Freeze dried microspheres	First-order kinetics	ln(100-Q)=-0.0029t+4.4197	0.98
	Higuchi equation	Q = 3.5029t^1/2+4.2236	0.983
	Weibull equation	lg[-ln(1-Q)] = 0.6517lgt-1.5349	0.996
	Ritger-Peppas equation	lnQ = 0.5425lnt+1.1755	0.989
	Bioexponential	100-Q = 98.382e^−0.0108t+76.292e^−0.0027t	Rα = 0.997 Rβ = 0.986
Lnxc-Sol	Zero-order kinetics	Q = 12.326t+44.402	0.771
	First-order kinetics	ln(100-Q)= -t+100	0.9999
	Higuchi equation	Q = 39.46t^1/2+ 20.022	0.8509

Figure 5.  Mean plasma concentration of Lnxc after intra-articular injection of Lnxc-Soland Lnxc-PLGA-MS in rabbits (n = 5).

Table 2.  The pharmacokinetic parameters of Lnxc after intra-articular injection of Lnxc-Sol and Lnxc-PLGA-MS in rabbits (n = 5)

Parameters	Lnxc-Sol	Lnxc-PLGA-MS
AUC(0-t))(μg/L*h)	6256.49	1245.542^**
MRT(0-t)(h)	15.301	46.012
CL(L/h/kg)	0.496	2.379
t1/2α(h)	25.584	69.315
t1/2β(h)	25.597	69.315
Tmax(h)	3	60
Cmax(μg/L)	400.79	31.61

Note: ^**P<0.01 vs Lnxc-Sol

Figure 6.  The distribution of Lnxc in synovial fluid of rats at different time points after intra-articular injection of Lnxc-Sol and Lnxc-PLGA-MS (n = 5).