Comparative in vitro dissolution of commercially available sustained release nifedipine tablet brands in the Kumasi Metropolis, Ghana.

The aim of this study was to assess the dissolution properties of twelve sustained release (SR) nifedipine tablet brands, including 20 mg and 30 mg innovator brands, for possible generic substitution. The tablet brands were purchased from retail pharmacies in the Kumasi Metropolis, Ghana. The weight uniformity, drug content and in vitro dissolution of the tablets in phosphate buffer pH 6.8 were evaluated. The dissolution data were compared using the similarity (f2) and difference (f1) factors, and the USP acceptance criteria for SR tablets. The kinetics of drug release from the tablets was also evaluated. All the brands passed the weight uniformity test. Nine brands (75 %) passed the drug content test while three brands (25 %) failed. The two innovator nifedipine SR brands passed all the tests undertaken. Comparison of the dissolution data using f1 and f2 showed that all three 30 mg nifedipine SR brands were dissimilar to the innovator brand. Also, two 20 mg nifedipine SR brands (28.6 %) were similar or bioequivalent with the innovator 20 mg brand while five brands (71. 4 %) were dissimilar. Three (75 %) 30 mg and four (50 %) 20 mg nifedipine SR brands exhibited appropriate drug release profiles based on the USP acceptance criteria. Drug release from the twelve tablet brands mostly followed the Higuchi kinetic model (58.3 %) followed by the Hixson-Crowell model (16.7 %). Only one brand (N7) exhibited constant drug release kinetics. Results from the study have shown that switching or substituting brands of SR nifedipine for patients should be guided by a critical assessment of the dissolution data using appropriate evaluation techniques.

Development of oral capsules from Enterica herbal decoction-a traditional remedy for typhoid fever in Ghana.

The study aimed to develop oral capsules from Enterica herbal decoction used in Ghana for the treatment of typhoid fever and produced by the Centre for Scientific Research into Plant Medicine (CSRPM). The amount of dry extract per dose (30ml) of Enterica and the wavelength of maximum absorption (λmax) of aqueous solutions of Enterica extract were determined. Light magnesium carbonate (LMC) and maize starch (MS) were employed as absorbents at various concentrations in the preparation of granules of the extract. The % loss in weight, size distribution and flow properties of the granules were evaluated. Enterica oral capsules were formulated using LMC at 22 mg/dose of extract and the dissolution properties of the granules and capsules were determined by UV-VIS spectrophotometry. The dry Enterica extract/dose was 190.1 ± 0.12 mg and λmax was 356 nm. The loss of granules was 2.07-7.31 %w/w for LMC and 2.73-7.81 %w/w for MS. LMC granules (22 mg/dose) prepared for encapsulation exhibited good flow properties. The granules for encapsulation exhibited optimal release of extract (86.08 ± 1.64 % at 45 min) in aqueous medium. The formulated capsules passed the British Pharmacopoeia uniformity of weight, disintegration and dissolution tests. Enterica oral capsules can be used as a substitute for Enterica decoction for the treatment of typhoid fever.

Potential of aqueous extract of Hibiscus sabdariffa calyces as colorin agent in three pediatric oral pharmaceutical formulations.

Aqueous extracts of Roselle or Hibiscus sabdariffa L calyces have characteristic intense red colouration due to the presence of anthocyanins which could be utilised as colouring agent in pharmaceutical products. The aim of the current study was to evaluate the potential of aqueous extract of H. sabdariffa calyces as a colouring agent in three pediatric oral pharmaceutical formulations. The colour value of H. sabdariffa calyx extract was determined colorimetrically at λmax 540 nm to be within the BP range of ≥ 0.25. The colour value of H. sabdariffa (0.26) was lower than that of amaranth (0.46), a synthetic commercial pharmaceutical colourant. H. sabdariffa calyx extract retained its colour value within the BP standard for up to six months. The aqueous extract of H. sabdariffa calyces at 33 % w/v was used as colouring agent in paracetamol syrup, diphenhydramine syrup and pediatric cough linctus and the colour stability of the formulations against temperature, light and pH were determined. H. sabdariffa calyx extract was less stable than amaranth to temperature, light and pH when used as a colouring agent. H. sabdariffa calyx extract at 33 % w/v has potential as a colouring agent in pharmaceutical formulations when buffered at pH 5.0, packaged in amber bottles and stored at low temperatures (26-37 °C).