Development and Validation of HPTLC Fingerprint Method for 16 Homeopathic Mother Tinctures Lacking Standards

High performance thin layer chromatography (HPTLC) is an important quality control method for homeopathic mother tinctures. Homeopathic Pharmacopoeia of India (HPI) provides standards for thin layer chromatography for many drugs. This study is aimed to develop HPTLC standards for those drugs for which TLC standards are not available in HPI. Sixteen drugs (Abrom. r., Bapt., Cass. fis., Cydo. vul., Dict. alb., Guat. gaum., J. ashok., Lactuc., Laur., Liat., Neg. ame., Olib., Onon. spi., Ruta, Chirata, and Ver. anth.) were identified for which TLC method is not available. The design of experiments (DOE) was formulated to determine solvents in the mobile phase, application quantity and dilution, and spray reagent with different combinations to develop separated chromatograms/fingerprints. The developed mobile phases were (9:10) in 11 out of 16 drugs, (80:10:10) in 2 out of 16 drugs, (40:40:10), (50:35:15), (100:15), and (100:11:11:26) are each in one drug. Spray reagent anisaldehyde was found compatible in 13 out of 16 drugs, and (NP/PEG) was used in 3 out of 16 drugs. Daylight, 254 nm, and 366 nm were used as light sources. HPTLC standards for 16 homeopathic drugs lacking entries in HPI were successfully developed. Continuous development of analytical standards is essential to support quality assurance in homeopathic formulations.