Application of a central composite design to evaluate the influence of colouring agents in lipstick formulation.

OBJECTIVES: The aim of this study was to evaluate by central composite design the influence of colouring agents in lipstick colour, expressed by L*, a*, b* parameters (CIELab system) where L* indicates lightness, and a* and b* are the chromaticity coordinates. The a* indicates colour direction from red to green and b* from yellow to blue. METHODS: Lipsticks were formulated as described by (Recent Adv. Prosp. Potent Med. Plants, 2009 and 39). The combined effect of three variables (dye, pigment and opacifier) was evaluated by different formulations in a central composite design. Colour parameters (L*, a*, b*) were analysed by reflectance spectrophotometry. Lipsticks were characterized by visual analyses and melting point. RESULTS: All formulations were integrate and homogeneous. The pigments and dye do not influence in colour transfer neither in melting point of lipsticks. On the other hand, results indicated that variables studied show influence only in parameter b*, whereas for L* and a* values there was no significant difference (P < 0.05). CONCLUSION: It was possible to verify that only the colour parameter b* was influenced by the variation in colouring agent's concentrations in lipstick formulation, leading to the production of the colour ranging between violet and light red. Such results are useful for developing new lipstick formulations to obtain the desired colour in the final product.

Zanthoxylum caribaeum (Rutaceae) essential oil: chemical investigation and biological effects on Rhodnius prolixus nymph.

A chemical investigation and bioassays against fifth-instar nymphae of the hematophagous insect Rhodnius prolixus, vector of Chagas disease, were conducted with the essential oil from Zanthoxylum caribaeum. The main results may be summarized as follows: (i) 54 components were identified, corresponding to 90.4% of the relative composition; sesquiterpenes (47.3%) and monoterpenes (41.2%) are the major constituents; (ii) muurola-4,5-trans-diene and isodaucene are described for the first time as chemical constituents of the essential oil from leaves of this species; (iii) topical treatment with the crude essential oil induced high levels of paralysis (from 18.88 to 33.33%) and mortality (from 80 to 98.9%) depending on the dose applied (0.5 to 5.0 µl per insect); (iv) feeding treatment with the crude essential oil also induced high levels of mortality (from 48.8 to 100%) but low levels of paralysis (from 2.22 to 7.77%) depending on the dose applied (0.5 to 5.0 µl/ml of blood); (v) in the continuous treatment, only the dose of 5.0 µl/cm(2) was able to promote statistical significant levels of mortality (63.3%) but no paralysis were detected. However in this group, occasionally, only few insects displayed malformations of legs and wings after treatment; and (vi) any treatment was able to disrupt the metamorphosis process since the low adult stage emergence observed to all groups was due the high insect mortality. These observations suggest the interference of Z. caribaeum compounds on the triatomine neuroendocrine system. The significance of these results in relation to the relevant biological events in R. prolixus as well as the possible use of insect growth regulators present in Z. caribaeum oil in integrated vector control programs against hematophagous triatomine species is herein discussed.

Effect of binders on 500mg metformin hydrochloride tablets produced by wet granulation

Metformin hydrochloride (MH) is an oral hypoglycemic agent and a high-dose drug that has poor flow and compression properties. In this study, the feasibility of developing adequate, low cost 500mg tablets of metformin hydrochloride by wet granulation was tested with several binders (Starch / PVP K30®; Starch1500® /PVP K30®, PVP K30® and PVP K90®) in a simple tablet press of the type used in small pharmaceutical laboratories. The drug powder was tested for ability to flow, by determining Carr?s Index (CI) and the Hausner ratio (HR). Differential scanning calorimetry and thermogravimetric analysis were carried out on isolated MH and 1:1 (w/w) binary mixtures with the excipients. The size distribution, friability, flow properties and drug content of the granules were analyzed, as were the hardness, friability, disintegration, dissolution and uniformity of the dosage form. The drug powder showed CI > 22% and HR > 1.25, characteristic of a poor flow powder, and no significant incompatibilities with the excipients. All the granules showed adequate flow properties and were suitable for pressing into tablets, all of which complied with pharmacopeial specifications. The starch /PVP K30® and starch 1500®/PVP K30® mixtures were best for producing 500 mg MH tablets.

Cloridrato de metformina é um fármaco hipoglicemiante oral que apresenta propriedades pobres de fluxo e compressibilidade. Este trabalho teve como objetivo o desenvolvimento de comprimidos de baixo custo,após granulação por via úmida, contendo 500 mg de cloridrato de metformina e diferentes aglutinantes (F1-amido / PVP K30®; F2- Starch 1500® / PVP K30®, F3-PVP K30®, F4- PVP K90®) em máquinas de compressão de baixo desempenho usadas em laboratórios farmacêuticos de pequeno porte. As propriedades defluxo do fármaco foram analisadas através do índice de Carr (IC) e fator de Hausner (FH). Cloridrato de metformina e suas misturas binárias com os excipientes na relação 1:1 (m/m) foram analisadas por calorimetria diferencial por varredura e análise termogravimétrica. Os granulados foram analisados quanto a distribuição granulométrica, friabilidade, propriedades de fluxo e teor e os comprimidos em relação à dureza, friabilidade, desintegração, dissolução e uniformidade de conteúdo.O cloridrato de metformina apresentou IC > 22% e FH> 1,25, característicos de fluxo pobre e não apresentou incompatibilidades com os outros excipientes. Todos os granulados demonstraram adequadas propriedades de fluxo e facilidade no processo de compressão. Os comprimidos apresentaram conformidade com as especificações farmacopeicas. As misturas amido / PVPK30® e Starch 1500® / PVP K30® foram mais adequadas para produzir comprimidos de cloridrato de metformina 500 mg.

Pharmaceutical equivalence of metformin tablets with various binders

Metformin hydrochloride is a high-dose drug widely used as an oral anti-hyperglycemic agent. As it is highly crystalline and has poor compaction properties, it is difficult to form tablets by direct compression. The aim of this study was to develop adequate metformin tablets, pharmaceutically equivalent to the reference product, Glucophage® (marketed as Glifage® in Brazil). Metformin 500mg tablets were produced by wet granulation with various binders (A equal starch, B equal starch 1500®, C equal PVP K30®, D equal PVP K90®). The tablets were analyzed for their hardness, friability, disintegration, dissolution, content uniformity and dissolution profile (basket apparatus at 50 rpm, pH 6.8 phosphate buffer). The 4 formulations, F1 (5% A and 5% C), F2 (5% Band 5% C), F3 (10% C) and F4 (5% D), demonstratedadequate uniformity of content, hardness, friability, disintegration and total drug dissolution after 30minutes (F1, F2 and F4), and after 60 minutes (F3). The drug release time profiles fitted a Higuchi model (F1, F2and F3), similarly to the pharmaceutical reference, or a zero order model (F4). The dissolution efficiency for all the formulations was 75%, except for F3 (45%). F1 andF2 were thus equivalent to Glifage®.