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Objective: This study aims to compare a generic formulation of the drug erlotinib 150 mg tablet to the brand-name version to validate the analytical method and bioequivalence studies.Methods: Erlotinib hydrochloride tablets (test versus reference formulation) were compared in a randomized, two-period crossover study to determine their pharmacokinetic properties and bioequivalence in healthy Iranian volunteers. 14 d passed between each treatment during the washout period. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyze erlotinib, and the method validation is presented.Results: Over the range of 6.25-3200 ng/ml, the analytical method was verified as linear (R2= 0.998). The technique was also accurate and precise at various concentrations. The results showed that the pharmacokinetics of the two products were comparable. Following administration of the test and reference products, the geometric averages for (Area under the curve) AUC0-72, AUCinf, and maximum plasma concentration (Cmax) were 104.71 (90% CI, 93.39-117.40), 104.68 (90% CI, 93.47-117.23), and 104.85 (90% CI, 94.61-116.21), respectively. The outcomes fell within the permitted tolerance of 0.8 to 1.25.Conclusion: For the determination of erlotinib in plasma, the used analytical approach is accurate, precise, repeatable, and selective. Additionally, the bioequivalence research revealed no appreciable differences in pharmacokinetic characteristics between the reference and test products. Therefore, it is possible to assert that the generic erlotinib product and the reference product are bioequivalent.
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Background: L-tryptophan is used widespread in the pharmaceutical industry. The majority of L-Trp production depends on microbial processes that produce L-tryptophan from indole and L-serine. These processes are very costly due to the costs of precursors, especially L-serine. Use of inexpensive substitutions as the L-serine source of Ltryptophan production enables us to reach a cost-effective process. In this paper, effect of Triton X-100 on L-Trp production and the ability to use Iranian cane molasses as inexpensive L-serine source was investigated
Methods: Escherichia coli [E. coli] ATCC 11303 cells were grown in 10-L fermenter containing minimal medium supplemented with beet molasses as an inexpensive carbon source and indole as tryptophan synthase inducer. Whole cells of stationary phase were used as biocatalyst for L-Trp production. Triton X-100 addition to the production medium as indole reservoir was investigated. Then, cane molasses was used as LSer source in L-Trp production medium. Amount of L-Tryptophan and theoretical yield of L-Trp production was determined by HPLC and by a colorimetrically method on the basis of remaining indole assay, respectively
Results: As a result, triton X-100 increased L-Trp production three times. Also, the result showed that 0.68 mM L-Tryptophan was produced in the presence of cane molasses at 37[degree]C for 8 hr
Conclusion: This result showed that cane molasses of Qazvin sugar factory includes significant amounts of L-Ser that makes it a suitable substitution for L-Ser in L-Trp production. Therefore, it has the potential to be used for cost-effective L-Trp production in industrial scale
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Tacrolimus, a cornerstone of immunosuppressive therapy in solid organ transplantation, has a narrow therapeutic range with considerable inter-individual and intra-individual pharmacokinetic variability. To date, there is no information on the pharmacokinetics of tacrolimus in Iranian liver transplant recipients. This study was designed to determine pharmacokinetic properties of orally administered tacrolimus in Iranian adult liver transplant recipients. Tacrolimus doses and steady state whole blood trough concentrations as well as patient demographic and clinical data were obtained retrospectively using the 30 included patients' medical records. Pharmacokinetic parameters were estimated by using a nonlinear mixed effect model program [Monolix version 3.1]. Absorption rate constant was fixed at two hours[-1]. Drug apparent clearance [CL/F], apparent volume of distribution [Vd/F], and elimination half life [t1/2 Beta] were calculated. The administered dose of tacrolimus to the patients ranged from 0.02 to 0.14 mg/Kg/day. Tacrolimus blood trough concentrations varied widely within the range of 1.8 to 30 ng/mL. The mean values of CL/F, Vd/F, and t1/2 Beta were found to be 9.3 +/- 0.96 L/h, 101 +/- 29 L, and 7.5 hours, respectively. The pharmacokinetics of tacrolimus was highly variable among our patients. CL/F, Vd/F, and t«? of tacrolimus in this study were comparable to reported values from Italian heart transplant patients but somewhat different from reported ones from other solid organ transplant populations