Formulation and Evaluation of Multilayered Tablets of Pioglitazone Hydrochloride and Metformin Hydrochloride

Table 3

Characteristic peaks of FTIR graphs.

Bond and frequency (cm^−1)	Pure drugs		Optimized multilayer tablet formulated with guar gum (cm^−1)
	Metformin (cm^−1)	Pioglitazone (cm^−1)
N–H (1°); 3400–3250	3368.23	—	3373.61
N–H (2°); 3400–3250	3148.15	—	3282.95
C=N; 1471–1689	1559.80	—	1566.25
C=O; 1760–1665	—	1741.90	1674.27
C–O; 1000–1300	—	1242.84	1244.13
C–S; 600–700	—	659.27	682.82
C=N; 1471–1689	—	1509.53	1533.46