Principles and Applications of Ultra-High-Performance Liquid Chromatography

The science of separation had advanced significantly with the development of ultra-high-performance liquid chromatography (UHPLC), a brand-new type of liquid chromatography. The need for the evolution of HPLC into UHPLC has been driven by the continuously evolving of packing material modifications that affect the separation of mixtures. The separation process of analytes is completed in a substantially decreased amount of time due to the lower particle sizes, which increases surface area of interaction allowing reduction of column length to one-third; thus, shorter columns are employed in UHPLC, which consequently causes the flow rate to be three times higher and subsequently reducing analysis time. Although UHPLC shares the same fundamental idea and instrument layout as HPLC, it differs from HPLC in that it produces narrow peaks and has high spectral quality, allowing for simple compound identification in a variety of analytical applications such as impurity profiling, product formulation, and improved analytical technique and method development. However, high back pressure in UHPLC might lead to decreased column life, and the instrument’s higher price compared to HPLC are the disadvantages

Self-medication practices in Mekelle, Ethiopia.

BACKGROUND: Self-medication makes consumers more health conscious, reduces treatment burden on healthcare facilities and curtails the cost and time of obtaining access to treatment. However, it increases risks such as drug resistance, adverse drug reactions, incorrect diagnosis, drug interactions and polypharmacy. The purpose of this study was to assess the practices and factors associated with self-medication in Mekelle, Tigray region, Ethiopia. METHODS: A cross-sectional study was undertaken in Mekelle from February to March 2013. A structured and pre-tested questionnaire was used for data collection to assess self-medication practices. Data were analyzed using of Statistical Package for Social Sciences (SPSS) version 20.0. RESULTS: Among self-medicated study participants, 199(73.7%) were males and 71(26.3%) were females with mean age of 28.65 years. The most frequently reported illnesses or symptoms of illnesses that prompted self-medication of study participants were headache/fever (20.7%), gastrointestinal diseases (17.3%) and respiratory tract infections (15.9%) with the main reasons being mildness of the disease, prior experience and less expensive. The majority of drug consumers made their requests by telling their symptoms, by mentioning specific names of the drugs and by showing old samples. Analgesics/antipyretics, gastrointestinal drugs, respiratory drugs and oral rehydration salt were the most frequently requested categories of drugs. Pharmacists followed by other healthcare providers were the most frequently reported source of drug information for self-medication. CONCLUSIONS: The results of this study demonstrated that self-medication practices were common for a wide range of illnesses. Health professionals, especially community pharmacists need to educate people on the benefits and risks of self-medication to encourage responsible self-medication

The prevalence of and factors associated with current smoking among College of Health Sciences students, Mekelle University in northern Ethiopia.

Tobacco smoking is one of the greatest causes of preventable morbidity and mortality globally, and is responsible for many causes of untimely deaths. This survey was aimed to determine prevalence and factors associated with current smoking among the students of College of Health Sciences, Mekelle University, Ethiopia.A cross-sectional study was employed using a structured self-administered questionnaire among College of Health Sciences students in March 2013. A stratified random sampling method was employed to select study participants. Data were entered and analysed using of Statistical Package for Social Sciences (SPSS) version 20.0.Of the 193 students, 57 (29.5%) of the students were current smokers. Most of the current smokers (89.4%) smoked between 1-10 sticks of cigarette per day. The two main reasons cited for smoking cigarettes were peer pressure (43.9%) and to relieve stress (36.8%). Being female (adjusted OR [AOR] = 0.49; 95% CI: 0.25, 0.95) and Tigre by ethnicity (AOR = 0.32; 95% CI: 0.14, 0.74) were significantly less associated with current smoking. On the other hand, being second year students (AOR = 3.84; 95% CI: 1.41, 10.46), khat chewing (AOR = 8.36; 95% CI: 2.60, 26.85) and taking illicit drugs (AOR = 10.59; 95% CI: 2.77, 40.51) were positively associated with current smoking cigarettes.The current smoking prevalence among students in College of Health Sciences, Mekelle University is high and therefore, effective smoking prevention and cessation intervention programs are required to reduce smoking among university students

New RP-HPLC Method Development and Validation for Dorzolamide in Ophthalmic Dosage Form

A reversed phase liquid chromatographic method with UV detection at 254 nm for dorzolamide assay in ophthalmic solutions was developed and validated. Chromatographic separation was achieved on a Zorbax SB C18 (250 mm × 4.6 mm, 5 µm) column kept at 30°C with an isocratic mixture of mobile phase (phosphate buffer, pH 2.5, and acetonitrile, 90 : 10 v/v) at a flow rate of 0.8 mL/min. The method was validated for its specificity, linearity, accuracy, precision, limit of detection, limit of quantification, and robustness based on ICH guidelines. The validation studies revealed satisfactory results. The proposed method has been applied for the quantification of dorzolamide in commercial samples. The developed method is fast, simple, specific, accurate, and sensitive, hence can be applied for routine quality control analysis of dorzolamide in pharmaceutical dosage form

Development and Validation of a High-Performance Liquid Chromatographic Method for the Determination of Cinitapride in Human Plasma

A precise and reliable reversed-phase high-performance liquid chromatographic method with ultraviolet detection was developed and validated to determine cinitapride in human plasma. After liquid-liquid extraction, chromatographic separation was achieved on a Nucleosil C18 (25 cm × 4.6 mm, 5 µm) column with an isocratic elution consisting of 10 mM ammonium acetate (pH 5.2), methanol, and acetonitrile, 40 : 50 : 10, v/v/v. The developed method was validated as per US FDA guidelines for its linearity, selectivity, sensitivity, precision, accuracy, and stability. Satisfactory findings were obtained from the validation studies. The linearity range of the method was 1 to 35 ng/mL while the extraction recovery of cinitapride in human plasma was more than 86%. The percent coefficient of variation of both intraday and interday precision was ≤7.1%

Type of requests for self-medication (n = 270).

<p>Type of requests for self-medication (n = 270).</p

Prevalence of smoking among CHS Students, March 2013 (N = 193).

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111033#pone-0111033-g001" target="_blank">Figure 1</a> indicates the prevalence of smoking among CHS students by gender. Out of the 193 respondents, 57 (29.5%) of the students were current smokers while 5 (2.6%) were former smokers.</p

Parent and drug related factors associated with current smoking among CHS Students, March 2013.

¶<p>Adjusted for mother’s education, friend smoking, alcohol consumption, khat chewing, taking illicit drugs and smoking harmful.</p><p>Parent and drug related factors associated with current smoking among CHS Students, March 2013.</p

Selected characteristics of current smokers in CHS, March 2013 (N = 57).

<p>Selected characteristics of current smokers in CHS, March 2013 (N = 57).</p

Reasons for self-medication (n = 270).

<p>Reasons for self-medication (n = 270).</p