GC-MS analysis of Adulterants in Captagon Tablet

In secret laboratories various synthetic or semi-synthetic amphetamine-type stimulants (ATS) are produced and processed. Stimulants of the form of amphetamine (ATS) are the second most common illegal drugs used worldwide, following cannabis. ATS production has increased worldwide, particularly from the Middle East. Fenethylline (CaptagonTM), a derivative of amphetamine, is commonly marketed as a street drug. Objective: this research aimed at applying gas chromatography / mass spectrometry (GC / MS) for fenethylline profiling of confiscated samples from the Saudi market. Methodology: The study of GC / MS was conducted on a general-purpose column (30 mm 0.25 mm i.d) filled with 0.25 mm cross bond, 5% diphenyl dimethyl polysiloxane (Rtx-5MS). The mass was worked in the process of impacting the electron. Results and discussion: Analyzed samples showed positive results for amphetamine in concentrations ranging from 0.07 to 43.02 percent of the substance in 60 percent of the samples. Caffeine was also present in 60 per cent of the samples at levels between 0.61 and 60.31 per cent. In the MS of the other active compounds were recorded in different proportions. Lastly, the presence of other substances in fenethylline samples may contribute to intoxication.

Investigation and Comparison of 5 % Diphenyl – 95 % Dimethyl Polysiloxane Capillary Columns

In gas chromatography, for the analysis, the most important thing is the well-chosen column. After having decided about which stationary phase is the best for our measurement and we know the length, the inner diameter and film thickness, we can buy the column from a lot of manufacturers. The products of these manufacturers’ look similar to each other, but they are different, because of the different manufacturing technologies. These differences could have significant influence on the separation. It is so important to compare the „same” columns, despite the manufacturers’ efforts to produce the best quality columns.5 % diphenyl – 95 % dimethyl polysiloxane stationary phase is widely used. Its slight polarity makes it able to determine very different compounds from the alkanes, through volatiles, drugs, fatty acid methyl esters, amines or phenols.In our work, we tested 5 % diphenyl – 95 % dimethyl polysiloxane stationary phase columns with an 8-component mixture. These columns were from different manufacturers. During isothermal conditions, we determined the height equivalent of theoretical plates on 8 linear velocity level. We represented these parameters as the function of linear velocity. With a constant linear velocity, we measured the excess sorption enthalpy and entropy. From the chromatograms we spotted differences in the retention and in resolution, which is important if we use the column for volatiles or for complex samples. With these parameters we can show many differences between the columns. These parameters have significant influence when we want to use our column for a given task.

Silicone-Thioxanthone: A Multifunctionalized Visible Light Photoinitiator with an Ability to Modify the Cured Polymers

A silicone-thioxanthone (STX) visible light photoinitiator was prepared by the nucleophilic substitution reaction of 2-[(4-hydroxybenzyl)-(methyl)-amino]-9H-thioxanthen-9-one (TX-HB) and γ-chloropropylmethylpolysiloxane-co-dimethyl-polysiloxane (PSO-Cl). Its structure was confirmed by 1H NMR, 13C NMR, FTIR, UV-vis and GPC. The photopolymerization kinetics of 1, 6-Hexanedioldiacrylate (HDDA) and trimethylolpropane triacrylate (TMPTA) initiated by STX confirmed that STX is an efficient photoinitiator. Its visible light photolysis experiment and the photopolymerization kinetics studies implied that a possible synergistic effect existed between two adjacent thioxanthone groups. Moreover, a higher migration stability was revealed in STX than 2-benzyl (methyl) amino-9H-thioxanthen-9-one (TX-B). STX could change the surface property of the cured film of polyurethane diacrylate prepolymer (PUA) from hydrophilic to hydrophobic, as well as change the thermal stability of the polymer network. Meanwhile, it could improve the resistance against water and acid. Thus, STX is an effective multifunctionalized photoinitiator.

Simple and Sensitive Methods for the Determination of 2-(4′-Chloromethyl phenyl) Benzonitrile and 2-(4′-Bromomethyl phenyl) Benzonitrile Contents in Valsartan Drug Substance by Gas Chromatography

Simple and reliable gas chromatographic methods were developed, optimized, and validated for the determination of 2-(4′-chloromethyl phenyl) benzonitrile (2-CMPB) and 2-(4′-bromomethyl phenyl) benzonitrile (2-BMPB) contents in valsartan drug substance, using benzophenone as internal standard (IS). Efficient chromatographic separations were achieved on DB-1, 30 m length with 0.53 mm i.d., and 3 μm particle diameter column consists of 100% dimethyl polysiloxane as a stationary phase by passing helium as a carrier gas. The analytes were extracted in dichloromethane and monitored by flame ionization detector. The performance of these methods was assessed by evaluating specificity, precision, sensitivity, linearity, and accuracy. The limits of detection (LOD) and limits of quantification (LOQ) established for 2-CMPB are 0.10 μg mL−1 and 0.32 μg mL−1, respectively. For 2-BMPB, LOD is 0.31 μg mL−1 and LOQ is 0.95 μg mL−1. The average recoveries for 2-CMPB are in the range of 96.8% to 106.7% and for 2-BMPB (LOQ level) are 99.3%. The methods can be successfully applied for the routine analysis of valsartan drug substance.

Safety Assessment of Cyclomethicone, Cyclotetrasiloxane, Cyclopentasiloxane, Cyclohexasiloxane, and Cycloheptasiloxane

Cyclomethicone (mixture) and the specific chain length cyclic siloxanes (n = 4-7) reviewed in this safety assessment are cyclic dimethyl polysiloxane compounds. These ingredients have the skin/hair conditioning agent function in common. Minimal percutaneous absorption was associated with these ingredients and the available data do not suggest skin irritation or sensitization potential. Also, it is not likely that dermal exposure to these ingredients from cosmetics would cause significant systemic exposure. The Cosmetic Ingredient Review Expert Panel concluded that these ingredients are safe in the present practices of use and concentration.