Dual Wavelength RP-HPLC Method for Simultaneous Determination of Two Antispasmodic Drugs: An Application in Pharmaceutical and Human Serum

Table 6

Summary of stability studies.

Test (claimed content)	Interval
	Initial	1 month	2 months	3 months	4 months	5 months	6 months	Mean	RSD%
Studies at accelerated (40°C + 75% H)
PG (10 mg/mL)	100.35	99.96	99.47	99.26	98.97	98.43	98.15	99.04	0.79
TMP (0.01 mg/mL)	99.85	98.98	98.41	98.13	97.97	97.86	97.53	98.15	0.80
Stability studies at long term (30°C + 65% H)
PG (10 mg/mL)	100.35	100.13	100.38	100.1	99.85	99.23	99.47	99.87	0.44
TMP (0.01 mg/mL)	99.85	99.62	99.39	98.93	98.91	98.37	98.12	98.89	0.64

All results are expressed in percentage values.