Document

Identification of PDE-5 inhibitors in Seized Materials using TLC and HPLC methods was developed and validated. TLC method, the stationary phase was siliga gel 60 F 254, the mobile phase comprised two systems. System 1 was the mixture of ethyl acetate, acetonitrile and ammonia solution and system 2 was the mixture of ethyl acetate, ethanol and ammonia solution. TLC of isolated sample was firstly detected by UV radiation at 254 nm, spectrum scanning and then confirmed by color reaction with ethanolic-sulfuric acid and acidified iodoplatinate reagent. In system 1, Rf were found to be 0.49, 0.71, 0.50, 0.57, and 0.56 for sildenafil, tadalafil, vardenafil, aminotadalafil, methisosildenafil, respectively. In system 2, the Rf were found to be 0.31, 0.78, 0.45, 0.72, and 0.43 for sildenafil, tadalafil, vardenafil, aminotadalafil, methisosildenafil, respectively. A purple color after spraying with ethanolic-sulfuric acid reagent indicated the presence of tadalafil and aminotadalafil. When acidified iodoplatinate solution was used, a brown to purple color developed indicated the presence of sildenafil, tadalafil, vardenafil and aminotadalafil. With TLC techniques, limit of detections of sildenafil, tadalafil and vardenafil were 100, 1000 and 250 μg/ml respectively. HPLC method, the separation was performed on a C18 column by isocratic elution with a mobile phase of 0.01 M ammonium acetate buffer and methanol and PDA detection at 210-350 nm. All sildenafil, tadalafil, vardenafil, aminotadalafil and methisosildenafil peaks were completely resolved as shown by resolution values greater than 1.8, with no interference from matrix components. With HPLC techniques, limit of detections of sildenafil, tadalafil, vardenafil, aminotadalafil and methisosildenafil were 3.8, 1.0, 2.5, 0.8 and 2.3μg/ml respectively. The validated method was applied to the identification of illicit drugs containing PDE-5 inhibitors in seized materials in fiscal year 2015. It was found that among 230 samples tested, 213 samples contained sildenafil, 11 samples contained a mixture of sildenafil, vardenafil, aminotadalafil, tadalafil and one sample contained a mixture of sildenafil and vardenafil. https://he02.tci-thaijo.org/index.php/dmsc/article/view/241326

Methamphetamine is a major drugs problem in the country. The spread of this drug and severity of the problem is continuing. One approach to control and reduce the spread of the drug is arrest and analysis of drug for further legal action. The analysis of drugs requires standard substance which is expensive and difficult supply. The aim of this study is to establish the shelf life of the methamphetamine standard solution prepared in BDN laboratory. The stability of methamphetamine standard solution was investigated by using a routine gas chromatographic technique, The quantitative detection of methamphetamine for illicit sample was performed in the duration of 128 days. Both methamphetamine standard solutions with the concentration about 0.4 milligrams per milliliter chloroform prepared and stored at 2-8 degree centigrade and the freshly prepared methamphetamine standard solution, were used for determination of methamphetamine content of illicit sample. At the end of the study periods, the percentage by weight different of two methamphetamine standard solution used was in the range of 0.11 – 1.96. This result showed that the expiry date of the methamphetamine standard solution was 128 days without any remarkable degradation. Therefore, all of illicit standard solutions should be studied for their expiry date to support the analysis of drug for the illicit drug control and legal action. https://he02.tci-thaijo.org/index.php/dmsc/article/view/241325

Department of Medical Sciences (DMSc) provides analytical testing to support law enforcement and conducts surveillance for drug abuse in Thailand. According to our analytical database, majority of drugs of abuse are benzodiazepines. In 2013, DMSc received seized material of light-orange, flat and round tablets, imprinted with “Erimin 5”. Erimin 5 is a brand name of benzodiazepine drug generally containing nimetazepam. The analytical testing of the seized tablets found no nimetazepam but further laboratory investigations revealed that the tablets contained phenazepam. The detection of phenazepam this time could be considered as a newfound drug of abuse in Thailand. Phenazepam is a potent and long acting benzodiazepine. It can be purchased on the internet and became drug misuse in Europe and USA. Many deaths caused by phenazepam have been reported. Phenazepam has not been scheduled as a controlled substance in the United Nation Convention Psychotropic Substances, nor in several countries including Thailand. It was suspected that phenazepam was used to replace nimetazepam in Erimin 5 tablets in order to avoid law enforcement. The purpose of this research is to present stepwise analytical techniques that lead to the identification of phenazepam in seized material. DMSc informed about this newfound sedative drug of abuse to the relevant authorities for further appropriate action. Consequently, the National Psychotropic Substance Control Committee had declared phenazepam as a Category I Controlled Psychotropic Substance according to the Thailand Psychotropic Substances Act B.E. 2518. https://he02.tci-thaijo.org/index.php/dmsc/article/view/241594