Mariusz Stolarczyk

Chromatographic and Densitometric Analysis of Hydrochlorothiazide, Walsartan, Kandesartan, and Enalapril in Selected Complex Hypotensive Drugs

Abstract A new chromatographic and densitometric method was developed for identification and determination of hydrochlorthiazide, walsartan, kandesartan, and enelapril present together in various complex drugs used in hypertension therapy. The TLC F254 plates were used as the stationary phase and two mobile phases were used of the following composition: ethyl acetate-tetrahydrufuran-acetic acid (8:2:0.5 v/v) (I) to determine kandesartan and walsartan present together with hydrochlorthiazide, and butane-1-ol-glacial acetic acid-water (12:3:5 v/v/v) (II) to determine enalapril and hydrochlorthiazide. The densitometric measurements were made at λ = 252 nm for walsartan and kandesartan and at λ = 274 nm and λ = 208 nm, for enalapril and hydrochlorthiazide, respectively. The method was specific to analyte constituents and was of high sensitivity; LOD ranged from 0.036 µg to 0.639 µg, LOQ from 0.210µg to 1.937 µg, recovery varied from 93.96{\percnt} to 101.74{\percnt}, the range of linearity was 0.078 µg to 6.150 µg. The results obtained for the drugs under examination was of similar precision, RSD ranged from 0.41 to 1.14.

Simultaneous analysis of hydrochlorothiazide, triamterene, furosemide, and spironolactone by densitometric TLC

A new chromatographic and densitometric method has been established for identification and quantitative analysis of hydrochloro-thiazide, triamterene, furosemide, and spironolactone, which are present, together, in complex drugs used to treat hypertension. For separation, silica gel F254 plates were used with hexane-ethyl acetate-methanol-water-acetic acid 8.4:8:3:0.4:0.2 (v/v) as mobile phase. Densitometric measurements were performed at 264 nm selected for all of the constituents. The method is specific for the analyte constituents examined, and characterized by high sensitivity; LOD is from 0.022 to 0.150 μg per band, LOQ from 0.068 to 0.450 μg per band, recovery from 97.10 to 101.02%, and linear range from 0.060 to 2.650 μg per band. The method is characterized by good precision with RSD from 0.66 to 0.96%.

Spectrophotometric method for simultaneous determination of valsartan and substances from the group of statins in binary mixtures

Abstract Applicability of derivative spectrophotometry for the determination of valsartan in the presence of a substance from the group of statins was checked. The obtained results indicate that the proposed method may be effective by using appropriate derivatives: for valsartan and fluvastatin - D1, D2 and D3, for valsartan and pravastatin - D1 and D3, for valsartan and atorvastatin - D2 and D3. The method was characterized by high sensitivity and accuracy. Linearity was maintained in the following ranges: 9.28-32.48 mg mL-1 for valsartan, 8.16-28.56 mg mL-1 f or fluvastatin, 14.40-39.90 mg mL-1 for atorvastatin and 9.60-48.00 mg mL-1 for pravastatin. Determination coefficients were in the range of 0.989-0.999 depending on the analyte and the order of derivative. The precision of the method was high with RSD from 0.1 to 2.5 % and recovery of individual components was within the range of 100 ± 5 %. The developed method was successfully applied to the determination of valsartan combined with fluvastatin, atorvastatin and pravastatin in laboratory prepared mixtures and in pharmaceutical preparations.

Simultaneous Determination of Acetylsalicylic Acid, Hydrochlorothiazide, Enalapril, and Atorvastatin in a Polypill-Based Quaternary Mixture by TLC

A new chromatographic-densitometric method has been developed for the qualitative and quantitative determination of the active ingredients in a simulated mixture corresponding to the PolyIran polypill, composed of acetylsalicylic acid, hydrochlorothiazide (HCT), enalapril (ENA), and atorvastatin (ATR), whose efficacy in the treatment and prevention of cardiovascular disease has been documented in clinical trials. Chromatographic separation was performed using TLC silica gel 60 plates with fluorescent indicator F254 as the stationary phase and a mixture of n-hexane-ethyl acetate-methanol-water-acetic acid (8.4 + 8 + 3 + 0.4 + 0.2, v/v/v/v/v) as the mobile phase. Densitometric measurements were carried out at λ = 210 nm when determining ENA and at λ = 265 nm in the case of the other drugs. Peaks of examined substances were well separated in the recorded chromatograms, enabling the evaluation of the results in terms of both qualitative and quantitative analysis. The method was specific for the analyzed components and was characterized by high sensitivity. The LOD was between 0.043 and 0.331 μg/spot, and LOQ was between 0.100 and 0.942 μg/spot. Recovery was in the range of 97.02-101.34%. The linearity range was broad and ranged from 0.600 to 6.000 μg/spot for acetylsalicylic acid, from 0.058 to 1.102 μg/spot for HCT, from 0.505 to 6.560 μg/spot for ENA, and from 0.100 to 1.000 μg/spot for ATR. The method was characterized by good precision, with RSD values that ranged from 0.10 to 2.26%.

Simultaneous Determination of Eight Hypotensive Drugs of Various Chemical Groups in Pharmaceutical Preparations by HPLC-DAD.

A new sensitive, simple, rapid, and precise HPLC method with diode array detection has been developed for separation and simultaneous determination of hydrochlorothiazide, furosemide, torasemide, losartane, quinapril, valsartan, spironolactone, and canrenone in combined pharmaceutical dosage forms. The chromatographic analysis of the tested drugs was performed on an ACE C18, 100 Å, 250×4.6 mm, 5 μm particle size column with 0.0.05 M phosphate buffer (pH=3.00)-acetonitrile-methanol (30+20+50 v/v/v) mobile phase at a flow rate of 1.0 mL/min. The column was thermostatted at 25°C. UV detection was performed at 230 nm. Analysis time was 10 min. The elaborated method meets the acceptance criteria for specificity, linearity, sensitivity, accuracy, and precision. The proposed method was successfully applied for the determination of the studied drugs in the selected combined dosage forms.