Spectrophotometric method for the determination of paracetamol and phenacetin.

A rapid, sensitive and simple spectrophotometric method is proposed for the determination of hydrolysis products of paracetamol (PRL) and phenacetin (PHN) with sodium 1,2-naphthoquinone-4-sulphonate and cetyltrimethyl ammonium bromide (CTA) in alkaline medium. The absorbances are measured at 570 and 500 nm and the molar absorptivities found to be 1.118 x 10(4) and 4.54 x 10(3) l mol-1 cm-1 for PRL and PHN, respectively. The coloured species conforms to Beer's law over the range 1-20 micrograms ml-1 for PRL and 2-24 micrograms ml-1 of PHN. The sensitivity is enhanced by the addition of CTA. The method is successfully employed for determination of PRL or PHN in various pharmaceutical preparations and laboratory made tablets and results have been statistically compared with those obtained by the official method.

Clinical study of yoga techniques in university students with asthma: a controlled study.

Adult asthmatics, ranging from 19 to 52 years from an asthma and allergy clinic in a university setting volunteered to participate in the study. The 17 students were randomly divided into yoga (9 subjects) and nonyoga control (8 subjects) groups. The yoga group was taught a set of breathing and relaxation techniques including breath slowing exercises (pranayama), physical postures (yogasanas), and meditation. Yoga techniques were taught at the university health center, three times a week for 16 weeks. All the subjects in both groups maintained daily symptom and medication diaries, collected A.M. and P.M. peak flow readings, and completed weekly questionnaires. Spirometry was performed on each subject every week. Analysis of the data showed that the subjects in the yoga group reported a significant degree of relaxation, positive attitude, and better yoga exercise tolerance. There was also a tendency toward lesser usage of beta adrenergic inhalers. The pulmonary functions did not vary significantly between yoga and control groups. Yoga techniques seem beneficial as an adjunct to the medical management of asthma.

Spectrophotometric methods for the determination of certain catecholamine derivatives in pharmaceutical preparations.

Two simple, rapid and sensitive spectrophotometric methods for the determination of catecholamine derivatives (pyrocatechol, dopamine, levodopa and methyldopa) are developed. The first method involves the oxidation of o-dihydroxybenzene derivatives by N-bromosuccinimide followed by oxidative coupling with isoniazid leading to the formation of a red-coloured products of maximum absorbance (lambda(max)=480-490 nm). The second method is based on the formation of green to blue complex (lambda(max)=635-660 nm) between o- dihydroxybenzene derivatives and sodium nitroprusside in the presence of hydroxylamine hydrochloride. All measurements of the two procedures are carried out in an alkaline medium at room temperature. The two methods are successfully applied for the determination of dopamine hydrochloride, levodopa and methyldopa in injections and tablets of pharmaceutical preparation. The common excipients used as additives in pharmaceuticals do not interfere in the proposed methods. The reliability of these methods are established by parallel determination with the reported and official methods.

Spectrophotometric determination of isoniazid with sodium 1,2-naphthoquinone-4-sulphonate and cetyltrimethyl ammonium bromide.

A rapid, sensitive and simple spectrophotometric method is developed for the determination of isoniazid (INH) with sodium 1,2-naphthoquinone-4-sulphonate and cetyltrimethyl ammonium bromide (CTA) in alkaline medium. Beer's law is obeyed in the range of INH concentrations of 2-5.6 mug ml(-1) at the maximum absorption of 500 nm. Sensitivity is enhanced by the addition of CTA. The method is successfully employed for the determination of INH in various pharmaceutical preparations and common excipients used as additives in pharmaceuticals do not interfere in the proposed method.