Analytical Method Development and Validation for the Simultaneous Estimation of Telmisartan and Atorvastatin in Bulk and Tablet Dosage Form

The current investigation was intended to improve the assay strategy for concurrent estimation of telmisartan and atorvastatin by utilizing instrument high performance liquid chromatography (HPLC), mobile phase of methanol:water, and 250 nm detection wavelength. The retention times were established to be 2.4 minutes for telmisartan and 3 minutes for atorvastatin. The analytical technique for both the drugs showed linearity over the range of 20 to 80 ppm of the target concentration. The recuperation was seen as 99.9% for both drugs. Both system framework and strategy precision were seen as precise and well inside the range. The detection limit of 0.05 for telmisartan and 0.019 for atorvastatin was found. The planned method was found to be simple, explicit, specific, linear, and rugged. Hence, it can be utilized for routine examination of telmisartan and atorvastatin in mass bulk and pharmaceutical formulations.

Comparison of extraction efficiency of various methods to extract L-DOPA from Mucuna pruriens (L.) DC.

Mucuna pruriens seeds are noted to be a natural source of L-DOPA and are also used as a substitute for the synthetic L-DOPA. In the present study; attempts are made to develop suitable method(s) for extraction of L-DOPA from the powdered seeds of Mucuna pruriens using different solvents and conditions. The Seed powder was subjected to 7 different extraction methods and Method 1 was subjected to various solvent concentrations. Some methods used de-fatting procedure, either the method was cold maceration or in high temperature. Soxhlet extraction was also used in one of the extraction methods. All the extracts were analyzed using RP-HPLC. Mobile Phase used was Water: Methanol: AcetoNitrile (100:60:40) (v/v) containing 0.2% Triethylamine, pH = 3.3 and monitored at 280 nm with variable wavelength UV detector. The extraction was best with Methanol Water mixture in a cold maceration technique and overall gives good extraction efficiency of 13.36 % L-DOPA and id the best method giving highest extraction efficiency. The De-fatting method was the 2nd best methods giving approximately 8.8% L-DOPA and Method 5 viz, heat reflux method gives 8.7% L-DOPA making it the 3rd best method. There are not many studies done for optimization of extraction technique for L-DOPA despite an extensive work is reported for isolation, identification and pharmacological activities of L-DOPA from various plant sources. Keeping this in view, present investigation was done to study the extraction efficiency of various extraction methods of L-DOPA content in seed extracts of Mucuna pruriens and compare it.

Determination of the Phenolic Composition and Antioxidant Activity of Pear Extracts

The specific HPLC analytical procedure was developed and validated for the determination of phenolic compounds in pear samples of different popular cultivars “Conference,” “Concordia,” “Grabova,” and “Patten.” HPLC mobile phase consisted of 0.05% (v/v) trifluoroacetic acid in water and 100% (v/v) acetonitrile. The HPLC method was used to identify and confirm the specificity of 8 analytes: chlorogenic acid, rutin, hyperoside, isoquercitrin, isorhamnetin rutinoside, quercitrin, quercitrin malonyl glucoside, and isorhamnetin glucoside. Repeatability % RSD did not exceed 3.87%, and intermediate precision did not exceed 4.63%. The total content of phenolic compounds varied from0.51±0.001 mg/g (cv. “Concordia”) to1.11±0.013 mg/g (cv. “Patten”). Chlorogenic acid was the major component in all the tested pear cultivars. The highest amount of chlorogenic acid (0.69±0.033 mg/g) was found in pear samples of the cultivar “Grabova,” and the highest amount of flavonol compounds (1.11±0.013 mg/g) was found in pear samples of the cultivar “Concordia.”

Application of an Optimized HPLC Method for the Detection of Various Phenolic Compounds in Apples from Lithuanian Cultivars

A specific analytical procedure including sample preparation and HPLC analysis was developed and validated for the detection of phenolic compounds in the samples of different apples from popular Lithuanian cultivars “Aldas,” “Auksis,” “Ligol,” and “Šampion.” The conditions for phenol extraction were optimized: the solvent of the extraction was 70% (v/v) ethanol, and the extraction was performed in an ultrasound bath for 20 min at the temperature of 40°C. The HPLC mobile phase consisted of 2% (v/v) acetic acid in water and 100% (v/v) acetonitrile. Using the HPLC technique, 11 analytes were identified, and their specificity was confirmed: procyanidin B1, (+)-catechin, chlorogenic acid, procyanidin B2, (−)-epicatechin, rutin, hyperoside, isoquercitrin, avicularin, quercitrin, and phloridzin. Chlorogenic acid was the major component in “Aldas,” “Auksis,” and “Ligol” and procyanidin B2 in “Šampion.” Hyperoside and avicularin were the dominant compounds of all the identified quercetin derivatives in “Aldas” and “Auksis;” hyperoside in “Šampion;” and quercitrin in “Ligol.” The total content of phenolic compounds varied from 1641.0 ± 47.9 μg/g (cv. “Ligol”) to 4291.3 ± 154.2 μg/g (cv. “Aldas”).

Ethyl lactate as an environmentally friendly HPLC mobile-phase modifier in the analysis of acetaminophen, caffeine, and ASA

Ethyl lactate (EL) has been investigated as an environmentally friendly organic modifier for use in HPLC mobile phases. EL shows significant promise in this regard when used under optimal conditions. In conjunction with a standard C18 column at a temperature of 60 °C, a mobile phase composed of 87% water, 10% EL, and 3% acetic acid is capable of baseline resolution of three standard pharmaceutical analytes (acetaminophen, caffeine, and acetylsalicylic acid) in under three minutes. This same mobile phase was found to be capable of extraction of these same analytes from consumer pain relief tablets with essentially 100% efficiency. Using a core-shell C18 column at 40 °C, similar resolution and run times with these analytes are possible using the same mobile phase but with a reduced EL content of only 2.5%.