Stability of ramipril in the solvents of different pH

Enhanced Stability of Ramipril in Nanoemulsion Containing Cremophor-EL: A Technical Note

“…Therefore, standard buffer pH 5 was selected as an aqueous phase for the preparation of ramipril nanoemulsion. It is well known that ramipril degrades in the presence of moisture and in alkaline pH (7,8). In our experiments, when nanoemulsion formulation of ramipril was prepared using distilled water as an aqueous phase, ramipril was found to be degraded as its concentration decreased rapidly.…”

“…The degradation of ramipril is believed to occur mainly via two pathways: (a) hydrolysis to ramipril-diacid and (b) cyclization or condensation to ramipril-diketopiperazine (ramipril-DKP). These ramipril-diacid and ramipril-DKP compounds form, as indicated above, as a result of cyclization, condensation, and/or breakdown arising from exposure to heat, air, moisture, alkali addition, stress, compaction, manufacturing processes excipients, storage conditions, thermal oxidation, or other interactions or events (7)(8)(9). It is thus generally difficult to select the excipients that enable dosage forms with adequate stability.…”

“…Ramipril and ramiprilat inhibit ACE and lowers blood pressure effectively (5,6). Formulation of ramipril dosage form leads to a decrease in the assay of ramipril due to mechanical stress, compression, manufacturing processes, excipients, storage conditions, heat, moisture, and alkaline pH (7)(8)(9). Since the drug is highly lipophilic (log p 3.32), it was presumed that keeping it in lipophilic environment might increase its stability.…”

Stability - Indicating Lc Method for the Simultaneous Determination of Telmisartan and Hydrochlorothiazide in Dosage Form

“…The methods [3][4][5][6][7][8][9][10][11] for telmisartan in combination with other drugs in plasma, serum and in tablets by high-performance liquid chromatography (HPLC) and [12][13][14][15][16][17] for the estimation of hydrochlorothiazide in combination with other drugs in serum and is in tablets by high-performance liquid chromatography (HPLC). A stability indicating LC method has been reported for telmisartan as well as hydrochlorothiazide.…”

Spectrophotometric and Atomic Absorption Determination of Ramipril, Enalapril Maleate and Fosinopril through Ternary Complex Formation with Molybdenum (V)-Thiocyanate (Mo(V)-SCN)

“…They include for ramipril, a kinetic spectrophotometry, 4) spectrophotometry and atomic absorption, 5) fluorimetry, 6) HPLC, 7) bioavailability assessment of nanoemulsion, 8) reversed-phase HPLC, 9) and liquid chromatography-mass spectrometry. 10) For enalapril, spectrophotometry using chelate formation with palladium(II) chloride, 11) spectrophotometry in the presence of its photo degradation products, 12) quantitative 1 H-NMR spectroscopy, 13) second-derivative ultraviolet spectrophotometry, 14) HPLC in the presence of the major active metabolite enalaprilate, 15) linear regression analysis and its application to multivariate chromatographic calibration, 16) HPTLC, 17) radio-immunoassay, 18) potentiometric titration 19) and differential pulse polarography (DPP).…”