Anna Apola

Densitometric determination of embelin in Lysimachia punctata

Athin layer chromatographic method with densitometric UV detection at λ = 285 nm has been developed for quantification of embelin in Lysimachia punctata. TLC analysis was performed on aluminumbacked silica gel 60 F254 plates with n-hexane—ethyl acetate, 7 + 3 (v/v), as mobile phase. Under these experimental conditions the method was highly sensitive (the limit of detection was 12.5 ng) and recovery was satisfactory (from 89.45% to 92.28%). Good results obtained during validation of the method were confirmed in quantification of embelin, because high precision and accuracy were achieved.

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.

Pharmacological and therapeutic properties of new derivatives of renin inhibitors and endothelin receptor antagonists, and the methods of their determination

According to data from the World Health Organization, cardiovascular diseases are the most common diseases of the 21st century. They are the reason for about 17 million deaths each year, including 9.4 million deaths caused by hypertensive disease or complications occurring during its course [http://www.thehealthwell.info/node/466541]. Therapeutic schemes in arterial hypertension include monotherapy or combination therapy involving administration of two or three drugs from various pharmacological groups, one of which should exhibit diuretic activity [Hypertension, 2003, 42, 1206–1252]. This review presents new information concerning analytical methods used in order to determine new substances of hypotensive activity belonging to two pharmacological groups, i.e., renin inhibitors and endothelin receptor antagonists.

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%.