Determination of Certain Drugs in Multicomponent Formulations by First Derivative Ultraviolet Spectrophotometry

Non-parametric linear regression of discrete Fourier transform convoluted densitometric peak responses

“…In the least squares calculation, however, the outlying point carries as much weight as the other points. This leads to the fact that, the least squares line passes closer to the outlier than the non-parametric line does [16,20] (Figs. 6-8) show examples illustrating these facts.…”

“…Application of derivative techniques to spectrophotometric data has become a well-established analytical method [15][16][17][18]. The elimination of interference by the use of derivative techniques depends on the fact that the first derivative of a constant function is zero and that of a linear function is constant.…”

First-derivative spectrophotometric determination of salbutamol in pharmaceutical preparations

“…The precision of the method for the assay of salbutamol in tablets was 1.0% with an average recovery of 98.8%. In the assay of the two-component preparation, the precision was 1.1 %, with average recoveries for salbutamol of 99.3% and for beclomethasone dipropionate of 99.4%.Derivative spectrophotometry is a fast and simple technique useful in the assay of multicomponent systems (Tobias 1983;Korany et al 1985) or single-component dosage forms in the presence of interfering excipients (Jones & Marnham 1981;Davidson & Hassan 1984). This technique was applied in the determination of salbutamol, a bronchodilator, as a singlecomponent in tablets, salbutamol sulphate and in combination with beclomethasone dipropionate in an aerosol.The official assay for salbutamol sulphate in tablets (British Pharmacopoeia 1988) indicates the use of an anionic ionexchange resin to retain interfering excipients before recording the absorbance value a t 276 nm.N o official procedure has been published for the quantification of salbutamol and beclomethasone dipropionate; an HPLC method has been reported by Hallworth & Westmoreland (1987).…”

“…Derivative spectrophotometry is a fast and simple technique useful in the assay of multicomponent systems (Tobias 1983;Korany et al 1985) or single-component dosage forms in the presence of interfering excipients (Jones & Marnham 1981;Davidson & Hassan 1984). This technique was applied in the determination of salbutamol, a bronchodilator, as a singlecomponent in tablets, salbutamol sulphate and in combination with beclomethasone dipropionate in an aerosol.…”

Efedrin Hidroklorürün Farmasötik Preparatlarda Dördüncü Türev UV Spektrofotometrisi ile Miktar Tayini : Determination of Ephedrine Hydrochloride in Pharmaceutical Preparations by Fourth Derivative UV

“…Bu nedenle çalışmamızda efedrin hidroklorürün luminal ve kodein fosfat ile üçlü karışım halinde bulunurken hiçbir ayırma işle-mine gerek duyulmaksızın hızlı, ucuz, kolay ve duyarlı olarak miktar tayinini gerçekleştirmeyi amaçladık. Bu amaca ulaşabilmek için de daha önce de çeşitli uygulamaları gösterilen (17,18) türev spektrofotometrisinden yararlandık.…”