ABSTRACT
Background: The optimization of polymer-drug conjugate design is important in effective and efficient delivery of poorly soluble drugs. Objectives: This work focuses on the formulation of novel amorphous ibuprofen-polymer nanoconjugates based on the polymer-drug complexation in order to improve its physical characteristics in the absence of toxic organic solvents. Methods: Amorphous Ibuprofen - DEAE-Dextran nanoconjugates were prepared using surfactant solubilization method. Physical characterization of the nanoconjugates was carried out via conductivity; surface tension; viscosity; transmittance/turbidity; particle size measurement; zeta potential; conjugation efficiency and Scanning Electron Microscopy (SEM) techniques. Results: A remarkably high loading capacity was achieved ranging from 89.05 to 96.34%. The conductivity measurements showed that the critical association concentration (cac) was exhibited at 2.34 mg/mL and critical micellar concentration (cmc) at 8.0 mg/mL. The presence of DEAE-Dextran decreased the cac of ibuprofen significantly (p 0.05; n
Subject(s)
Chemistry , Dextrans , Ibuprofen , Pharmaceutical Preparations , Surface-Active AgentsABSTRACT
PURPOSE: Kaolin is a known adsorbent; has lubricant property in powders and is therefore proposed as a lubricant in tablet formulations. This study was carried out to evaluate whether kaolin can adsorb some active drugs when mixed with them in tablet formulations even at very low concentrations. METHOD: Chloroquine and chlorpheniramine tablets were formulated with powder mixtures containing various concentrations of kaolin. The effect of kaolin on the physical properties of the tablets were examined and compared with those of standard lubricants like magnesium stearate and talc. Chloroquine and chlorpheniramine tablets and powders of amoxicillin/clavulanic acid oral powder and ampicillin/cloxacillin injection were also mixed with and without various concentrations of kaolin in water. Chemical assay of the drugs in the solutions were determined over time. RESULTS: Kaolin significantly reduced the amount of each of the drugs in the solutions containing kaolin. CONCLUSION: Kaolin reduces the amount of some drugs when incorporated in drug formulations. Therefore; its inclusion in such drug formulations should not be encouraged
Subject(s)
Adsorption , Ampicillin , Chemistry , Chloroquine , Chlorpheniramine , Kaolin , Pharmaceutical PreparationsABSTRACT
A pharmaceutical formulation is aimed at ensuring drug delivery at the site of action in order to produce the desired therapeutic effect. The design of a pharmaceutical formulation must reflect the chemical reactivity of the drug substance as well as those of any other substances that are used in the formulation. Standardized manufacturing procedures which conform to accepted codes of Good Manufacturing Practices are prerequisites for the preparation of pharmaceutical formulations for optimal drug delivery. Drug formulations produced by such methods are expected to have the desired bioavailability characteristics for pharmacotherapy. The different types of pharmaceutical formulations usually prepared for administration by various routes are aimed at achieving the most appropriate drug delivery system for each drug. When necessary; special drug delivery systems are designed to achieve this objective. Advances in biotechnology has led to production of labile substances for use as drugs in therapy and this has created new challenges in the development of novel drug delivery systems. [abstract terminated]
Subject(s)
Chemistry , Drug Administration Routes , Drug Delivery Systems , TechnologyABSTRACT
Des analyses chimiques qualitatives et quantitatives ont ete effectuees sur trois medicaments antidiarrheiques utilisees en medecine traditionnelle dans la province du Centre (Cameroun): myrianthus arboreus (medication I); combretum sp (medication II); holarrhena sp (medication)
Subject(s)
Antidiarrheals , Chemistry , Diarrhea/drug therapy , Medicine , PlantsABSTRACT
Nous avons etudie la composition chimique et la variabilite de l'huile essentielle de l'hybride MS-41 fertile obtenu a partir du croisement entre mentha sacharinensis et mentha incana. Il a ete etabli que cet hybride differe des formes initiales steriles par l'augmentation du nombre de chromosomes et l'apparition dans l'huile essentielle du pulegone et du menthofurane. L'etude de 62 plantes issues de l'autofecondation de cet hybride indique qu'il existe une variation quantitative considerable de l'huile essentielle et de ses principaux constituants; toutefois le trait dominant reste la biosynthese du menthol (50 a 90 pour cent). La composition chimique de l'huile essentielle ne change pas
Subject(s)
Chemistry , Oils , ReproductionABSTRACT
L'etude; de juillet 1988 a mai 1989; de la variation des huiles essentielles des lippia cultives (Brazzaville; Congo) met en evidence un mouvement continu de ces huiles des fleurs vers les feuilles et inversement. La teneur des differents constituants varie de facon plus ou moins prononcee selon la partie de la plante consideree alors que le profil global des huiles reste le meme. Cette etude permet de situer la periode de recolte la plus favorable pour cette plante a effets bactericide et antifongide etablis
Subject(s)
Chemistry , Oils , PlantsABSTRACT
15 huiles essentielles d'eucalyptus ont ete analysees par chromatographie en phase gazeuse et testees vis-a-vis de 9 souches bacteriennes. La composition et la proportion relative des composes des huiles essentielles analysees varient d'une espece a une autre. Les essais antimicrobiens ont permis de remarquer d'interessantes proprietes antimicrobiennes