Table 1.

Formulations of PLGA cylinders containing OP and GEM and drug release from cylinders after 72 h in 0.1 M phosphate buffer (pH 7.4) at 37°C

Number of layers	PLGA (mg)	Layer arrangement, inner/outer	OP (mg)	GEM (mg)	Film storage	Release after 72 h (%)
1	80	–	16	3	24 h, 4°C	OP: 86 GEM: 61
	160	–	16	3	24 h, 4°C	OP: 86 GEM: 72
	320	–	16	3	24 h, 4°C	OP: 58 GEM: 31
2	160 (80 mg/layer)	OP/GEM	8	1.5	24 h, 4°C	OP: 3 GEM: 36
		GEM/OP	8	1.5	24 h, 4°C	OP: 12 GEM: 1
2	160 (80 mg/layer)	OP/GEM	16	3	24 h, 4°C	OP: 87 GEM: 18
		GEM/OP	16	3	24 h, 4°C	OP: 73 GEM: 3
2	160 (80 mg/layer)	OP/GEM	16	3	72 h, 20°C	OP: 21 GEM: 43
		GEM/OP	16	3	72 h, 20°C	OP: 53 GEM: 2

Notes: Double-layered PLGA cylinders in which the OP was contained within the inner cylinder and the GEM was contained within the outer cylinder are designated as OP/GEM, and cylinders in which the GEM was contained within the inner cylinder and the OP was contained within the outer cylinder are designated as GEM/OP. ‘–’ indicates not applicable as there was only one inner/outer layer arrangement.

Abbreviations: GEM, gemcitabine; OP, oseltamivir phosphate; PLGA, poly(d,l-lactic-co-glycolic acid).