ABSTRACT
The degradation behavior of cefquinome sulphate in alkaline medium at different temperatures was investigated using both first derivative spectrophotometric and HPLC methods. The drug degradation was found to be pH and temperature dependant. The pH-rate profile indicated a first order dependence of Kobs on [OH(-)] at pHs ranging between 9 and 11. Arrhenius plot obtained at pH 10 was linear between 65° and 100°C. The estimated activation energy of the hydrolysis was found to be 21.1 kcal mol(-1). Stability-indicating thin-layer chromatographic method for the separation of the drug and its alkaline hydrolysis product has been developed.
Subject(s)
Attitude of Health Personnel , Consultants , Electronic Mail , Practice Patterns, Dentists' , Surgery, Oral , Surveys and Questionnaires , Dental Research/standards , Dental Research/statistics & numerical data , Humans , Reproducibility of Results , Research Design , Surveys and Questionnaires/standardsABSTRACT
Two simple spectrophotometric methods were developed for the determination of cefprozil in pure bulk and in tablets forms. The first is a colorimetric method based on the coupling of cefprozil, after being hydrolyzed by sodium hydroxide (0.1N), with ascorbic acid as a chromogen (method A). It has been established that cefprozil reacts with ascorbic acid to form a 1:1 water soluble colored product with maximum absorbance (λmax) at 408 nm and molar absorptivity of 7.2 × 10(3)L mol(-1) cm(-1). The second method (Method B) utilizes a direct reaction between cefprozil and sodium hydroxide (1N). A colored product with λmax at 486 nm and molar absorptivity of 7.4 × 10(3) L mol(-1) cm(-1) is formed after heating cefprozil with sodium hydroxide (1N). The absorbance-concentration plot was rectilinear over the range 5-25 µg/ml in both methods with correlation coefficient values not less than 0.999. The detection limits (L.O.D.) were 0.96 µg/ml and 0.93 µg/ml for method A and method B respectively. The methods were validated using the USP liquid chromatography method for cefprozil assay. The results obtained by the USP liquid chromatography method for the tablets dosage form were statistically compared with those of the developed methods and evaluated at 95% confidence limits.
ABSTRACT
There are few robust, evidence-based data about what constitutes the diagnosis of atypical facial pain and how it is best treated. We therefore aimed to find out the current opinion of those on specialist lists in the United Kingdom (UK) on whether they use the term atypical facial pain, how they reach their diagnosis, and what treatment they offer. We sent out questionnaires to 240 specialists randomly selected from the UK lists of those most likely to deal with atypical facial pain (oral and maxillofacial surgeons, oral medical specialists, ear nose and throat surgeons, anaesthetists, psychiatrists and neurologists). We divided the replies according to whether the specialists were medically or dentally based. Of the 209 valid questionnaires, 143 were returned (a response rate of 68%); 127 of the 143 used the term atypical facial pain, the others used various other terms. The two groups used significantly different criteria, mainly to exclude other conditions to achieve a diagnosis. About half used haematological tests and most used radiographic investigations routinely, and there were no significant differences among the specialities. No unified pattern of referral between different units was found. Treatment was mainly by antidepressant and anticonvulsant drugs, and counselling.
