Development of a Technique for Chromatographic Analysis of Excipients in a Liposomal Dosage Form of a Photosensitizer Tetra-3-phenylthio-phthalocyanine Hydroxyaluminium

Abstract

Introduction. The Laboratory of Drug Formulation Development at the N. N. National Medical Research Center of Oncology developed a liposomal dosage form of FS tetra-3-phenylthio-pthalocyanine hydroxyluminide (TPHA) for which a simple, accurate and easily reproducible method of quantitative determination of the main active substance and excipients in the drug product was needed. High-performance thin-layer chromatography (HPTLC) was chosen as such a technique.Aim. The aim of this work was to develop chromatographic methods for the quantitative determination of excipients in a liposomal dosage form of a tetra-3-phenylthiophthalocyanine hydroxyaluminium (TPHA).Materials and methods. Determination of substances was carried out by the method of high-performance thin-layer chromatography (HPTLC) followed by TLC-densitometry. Substance TPHA 98 % (Federal State Unitary Enterprise "SSC "NIOPIK", Russia), placebo lyophilized liposomal form without TFHA in the composition (FSBI "National Medical Research Center of Oncology. N. N. Blokhin" of the Ministry of Health of Russia), egg phosphatidylcholine (96 %, CAS № 97281-44-2, EPC Lipoid, Germany), cholesterol (≥99 %, CAS № C8667, Sigma-Aldrich, Japan), sucrose analytical grade (CHIMMED, Russia) and various organic solvents.Results and discussion. The selected mobile phase for HPTLC analysis: isopropanol: ammonia 25 % aqueous 80 : 20, separation time was 20–25 min (l = 75mm), t = 20 °С. To visualize the spots of sucrose, phosphatidylcholine, and cholesterol, a 5 % solution of phosphomolybdic acid was chosen. The stability of the standard samples was confirmed on a series of prevalidation studies. Validation of the methodology was carried out.Conclusion. For quantitative determination of sucrose, phosphatidylcholine and cholesterol in a new liposomal dosage form, the method of HPTLC with TLC-densitometry was chosen, which allows identifying all three components in the dosage form simultaneously. The method was validated.

Keywords

• methods of analysis
• high-performance thin-layer chromatography
• liposomes
• phosphatidylcholine
• cholesterol