Assessing compatibility of excipients selected for a sustained release formulation of bilberry leaf extract

Abstract The study is aimed to assess the compatibility of bilberry leaf powder extract (BLPE) with six excipients selected for sustained-release (SR) tablet formulation. The BLPE was obtained with the addition of L-arginine and Myo-inositol as the carriers. Thermogravimetric (TG-DTG) analysis and Fourier-transform infrared spectroscopy (FTIR), supported by Pearson correlation analysis, were applied to detect possible interactions in the binary mixtures (1:1) of the BLPE with each excipient. The TG-DTG showed some deviations in the thermal behavior of the BLPE / excipient mixtures. However, only the thermal behavior of magnesium stearate in the mixture significantly differed from individual samples, which suggested chemical interaction for this excipient. The FTIR analysis confirmed that the BLPE is compatible with Eudragit L100, Methocel K4M, Methocel K100LV, Avicel PH-101, and Plasdone S-630. Whereas it undergoes solid-state chemical interaction in the binary mixture with magnesium stearate. According to the FTIR-spectra, it is suggested that this interaction results in the formation of stearic acid and alkalization of the medium. These findings evidence for the possibility of using TG-DTG analysis as an independent thermal technique for compatibility studies and also confirm the earlier reported interaction of basic lubricants, e.g., stearic salts, with active ingredients containing amino groups.

Comparative Characteristics of Anti-depressant, Anti-hypoxic Action, and Effect on the Physical Endurance of Scutellaria baicalensis Drugs.

OBJECTIVES: The influence of original drugs from Scutellaria baicalensis (SB) Georgi (dry extract, powder of rhizomes and roots, tablets "Scutex" on the basis of the dry extract and capsules "Scutella", which contain powder of rhizomes with roots) was studied on depressive behavior, physical endurance and anti-hypoxic activity in mice. MATERIALS AND METHODS: The used dry extract SB (SBDE), powder of roots and rhizomes from SB (SBRP), tablets from dry extract of SB named "Scutex", and hard gelatin capsules from the crushed root of SB named "Scutella" were obtained from National University of Pharmacy, Department of Industrial Technology of Drugs. In the experiment, 94 random-breed white male mice weighing 20-29 g were used and kept in standard sanitary and laboratory conditions. RESULTS: The experiments revealed that SBDE had anti-depressant action. Powder from rhizomes and roots of SB and "Scutella" capsules had anti-hypoxic action. All test drugs showed no influence on the physical endurance of mice. These results suggest the possible use of SBDE as an anti-depressant drug, and rhizomes with roots and "Scutella" capsules as an anti-hypoxic remedy. CONCLUSION: SBDE at a dose 50 mg/kg shows anti-depressant activity that exceeds the activity of the comparison drug "Bilobil". SBDE, SBRP, "Scutex" tablets and "Scutella" capsules do not affect the physical endurance of mice. SBDE at a dose 50 mg/kg and SBRP at a dose of 173 mg/kg and 260 mg/kg exhibit anti-hypoxic activity. "Scutex" tablets show no anti-hypoxic action and "Scutella" capsules cause probable anti-hypoxic action that exceeds the effect of the reference drug "Bilobil".