Development and Validation of an HPLC Method for Simultaneous Assay of MCI and MI in Shampoos Containing Plant Extracts

Table 8

Results of stability studies.

Studies	Average retention time (minutes)	Average peak area (mAu.s)	Average asymmetry of peak	Average number of theoretical plate	RSD (%) of peak area	Recovery (%)
MI
(i) Standard solution
Initial	7.695	41236	1.4	3131	0.3	—
After 24 h	7.703	40697	1.4	3027	0.4	98.7
(ii) Sample solution
Initial	7.711	38263	1.4	3142	0.2	—
After 24 h	7.692	37851	1.4	3129	0.4	98.9
MCI
(i) Standard solution
Initial	15.638	71554	1.1	4940	0.2	—
After 24 h	15.674	70981	1.1	4852	0.3	99.2
(ii) Sample solution
Initial	15.592	67083	1.1	4910	0.1	—
After 24 h	15.613	66348	1.1	4815	0.3	98.9