Table 1.

Effect of storage time on polyox tablet containing different drugs hardness stored at 40 °C

PEO/drug	Time (week)	Hardness ratio 1:1
750/propranolol	Fresh	93.1 ± 0.5
750	2 weeks	88.0 ± 0.5
750	4 weeks	84.0 ± 0.2
750	8 weeks	79.2 ± 0.1
303/propranolol	Fresh	100.3 ± 0.1
303	2 weeks	94.5 ± 1.0
303	4 weeks	89.0 ± 0.5
303	8 weeks	84.1 ± 0.3
750/theophylline	Fresh	95.5 ± 1.0
750	2 weeks	93.9 ± 0.5
750	4 weeks	91.5 ± 0.4
750	8 weeks	86.1 ± 0.1
303/theophylline	Fresh	105.0 ± 0.5
303	2 weeks	104.5 ± 0.2
303	4 weeks	104.2 ± 0.4
303	8 weeks	104.0 ± 1.0
750/zonisamide	Fresh	96.0 ± 0.5
750	2 weeks	98.1 ± 0.3
750	4 weeks	99.5 ± 0.3
750	8 weeks	102.0 ± 0.4
303/zonisamide	Fresh	108.0 ± 1.0
303	2 weeks	114.0 ± 0.5
303	4 weeks	122.0 ± 2.0
303	8 weeks	133.0 ± 1.0