Journal of pharmaceutical and biomedical analysis
-
J Pharm Biomed Anal · May 2019
Development and validation of an HPLC-UV method for simultaneous determination of sildenafil and tramadol in biological fluids: Application to drug-drug interaction study.
The introduction of sildenafil (SDF) to treat erectile dysfunction has solved a widespread condition with negative on the quality of life. Recently, the co-administration of tramadol (TMD) with SDF to manage premature ejaculation has illegally increased and thus drug-drug interaction studies of these drugs became of great importance. Although certain biological functions have been altered upon co-administration of the two drugs, methods for their determination in vivo to understand their interactions have yet to be published. ⋯ In addition, the metabolites N-desmethylsildenafil (UK-103,320) and O-desmethyltramadol were quantified in rabbit plasma after 2 h of oral administration using LC-MS/MS. The simultaneous administration of TMD with SDF has affected peak plasma concentration (Cmax), Tmax, area under the concentration-time curve (AUC), and the elimination rate constant (Kel) of SDF. The present study is the first to give valuable insights into the drug-drug interaction and the pharmacokinetic implications associated with the co-administration of SDF and TMD.
-
J Pharm Biomed Anal · Apr 2019
Identification of anti-inflammatory components in Sinomenii Caulis based on spectrum-effect relationship and chemometric methods.
The present study aimed to identify the anti-inflammatory components in Sinomenii Caulis (SC) based on spectrum-effect relationship and chemometric methods. A phytochemical investigation of SC extract was performed firstly and afforded eleven potential bioactive compounds. The HPLC fingerprints of 19 batches of SC samples were evaluated by the chemometric methods such as similarity analysis (SA) and hierarchical clustering analysis (HCA). ⋯ The results indicated that there was a close correlation between chemical fingerprint and anti-inflammatory activity of SC, and peaks 8, 9, 12, 13, 14, 16, 19 and 22 might be potential anti-inflammatory compounds in SC. The verification experiments by testing individual compounds and a combination of them indicated that sinomenine (P8), magnoflorine (P13), menisperine (P16) and stepharanine (P19) were the major anti-inflammatory compounds in SC. Collectively, the present study established the spectrum-effect relationship mode of SC and discovered the anti-inflammatory compounds in SC, which could be used for exploration of bioactive components and quality control of herbal medicines.
-
J Pharm Biomed Anal · Feb 2019
ReviewNDMA impurity in valsartan and other pharmaceutical products: Analytical methods for the determination of N-nitrosamines.
Batch recalls for valsartan containing pharmaceutical products in July 2018 initiated a discussion on possible contaminations with N-nitrosodimethylamine (NDMA). It appeared that NDMA was generated during synthesis of the active pharmaceutical ingredient (API) from the solvent dimethylformamide (DMF) and the reagent nitrite. Discussion on NDMA as API impurity is extended to other drugs since then. ⋯ However, current availability of this combination is very limited. Alternatively, LC-MS/MS is also performed in NA analysis. An integration of a general test in future pharmacopoeias is suggested due to the toxicological relevance and broader spectrum of possible APIs that may be affected.
-
J Pharm Biomed Anal · Feb 2019
Case ReportsReliable and easy-to-use LC-MS/MS-method for simultaneous determination of the antihypertensives metoprolol, amlodipine, canrenone and hydrochlorothiazide in patients with therapy-refractory arterial hypertension.
Therapy-refractory arterial hypertension is defined as a blood pressure (BP) in a subset of patients who fail to achieve BP control despite a three-drug regimen (including a diuretic). Various factors have impact on loss of therapy response. Drug-drug-interactions (DDIs) may cause altered pharmacokinetics (PK) of antihypertensive drugs. Upregulation of activity and expression of cytochrome P450 (CYP) enzymes can result in decreased plasma drug levels. Besides these PK considerations a significant problem could be nonadherence to drug therapy. In this regard Therapeutic Drug Monitoring (TDM) is a useful tool for detecting nonadherence. Therefore a LC-MS/MS-method for determination of Metoprolol (MET), Amlodipine (AML), Canrenone (CAN) and Hydrochlorothiazide (HCT) was developed. ⋯ Although the level of recommendation of TDM of antihypertensive drugs in patients with refractory hypertension is not yet established, the present LC-MS/MS-method can serve as an effective tool for detection of PK-alterations/nonadherence and may help to monitor antihypertensive pharmacotherapy.
-
J Pharm Biomed Anal · Oct 2018
Chemical analysis, pharmacological activity and process optimization of the proportion of bilobalide and ginkgolides in Ginkgo biloba extract.
Variations on the efficacy of commercial Ginkgo biloba preparations have been reported, although all the products follow the same standards. Terpene trilactones (TTLs), including bilobalide (BB) and ginkgolides, are one of the main active components in G. biloba extract and have been received the most attention due to their chemical uniqueness and their importance for quality control. A plenty of studies demonstrated that BB and ginkgolides display differential activities on various biological processes. ⋯ Within this design space, G. biloba extraction process can be guaranteed to achieve the better BB and ginkgolides ratio with high assurance. Normal operation space for G. biloba extraction process was recommended as ethanol concentration of 50% to 70%, liquid-to-solid ratio of 5.6 mL/g to 7.3 mL/g, and extraction time of 2.2 h to 3.0 h. This work not only suggest that the proportion of BB and ginkgolides should be used as a quality control index in ginkgo preparations besides the content of TTLs, but also provide a way to approach it with the extraction process parameters controlled in the normal operation ranges.