[Lotion with hydroquione - tretinoin].

The observed precipitation in a lotion containing 4% of hydrochinon and 0,03% of tretinoine is evaluated. To dissolve both actives, 10% propyleneglycol is used and the alcohol concentration varied. From the results it is demonstrated that at least 54 ml of ethanol 96 degrees is necessary to dissolve both actives.

[Pharmacy compounding of an omeprazole suspension].

The problems of preparation of different pharmaceutically compounded formulations of prescribed omeprazole suspensions are discussed. Problems that can be cited are: inadequate preparation, chemical and physical stability problems, taste problems and low bioavailability. The formulation of the omeprazole suspension is optimized, taking into account the cited problems.

Evaluation of Artemisia annua infusion efficacy for the treatment of malaria in Plasmodium chabaudi chabaudi infected mice.

The efficacy of artemisinin (AR) against malaria has prompted its use as a tea drink in endemic communities. However, there is controversy about its efficacy in this form. Therefore we have investigated the effectiveness of Artemisia annua infusion in infected mice.

Development and validation of a simple thin layer chromatographic method for the analysis of artemisinin in Artemisia annua L. plant extracts.

Owing to the development of parasite resistance to standard antimalarial treatments like chloroquine and sulfadoxine-pyrimethamine, the demand for Artemisia annua, a key ingredient for new and highly effective antimalarial drugs, is huge. Therefore selective and precise methods to determine the content of artemisinin in dry plant material and in raw impure extracts are needed. In this work a method is described for the clear separation and extraction of artemisinin from other plant components in the Artemisia annua L.

Influence of preparation method on itraconazole oral solutions using cyclodextrins as complexing agents.

In the literature, solubility values of itraconazole complexed with 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) were found which were still much too low to obtain the target concentration of 1 g itraconazole/100 ml, the concentration of the marketed itraconazole formulation Sporanox (Janssen Pharmaceutica). Therefore, we compared two preparation methods: the classical and the dissolving method to investigate if the method of preparation can have an influence on the solubility of itraconazole complexed with cyclodextrin (CD). With the classical method, the active compound and the CDs are jointly dissolved with a co-solvent, propylene glycol, in water.

Development of an omeprazole parenteral formulation with hydroxypropyl-beta-cyclodextrin.

Because of both the low solubility and stability of omeprazole in an aqueous environment, cyclodextrins (CDs) were added as inclusion complexation agents and stability enhancers in a parenteral formulation. Stability curves of omeprazole in different aqueous media were compared to determine which was most appropriate to prepare a formulation. The aimed preparation contains 40 mg omeprazole in an as low a volume of solvent as possible.

Quality evaluation of chloroquine, quinine, sulfadoxine-pyrimethamine and proguanil formulations sold on the market in East Congo DR.

Objective: Drug quality may be poor in many regions of the world. Our first aim was to verify whether the dose of the active compounds in various antimalarial medicines on the market in East Congo conforms to the quality requirements of the European Pharmacopoeia (Ph. Eur.

Preparation and evaluation of paclitaxel-containing liposomes.

Paclitaxel, an antitumoral drug, is poorly soluble in aqueous media. Therefore, in a commercialised formulation (Taxol), paclitaxel (30 mg active compound) is dissolved in polyethoxylated castor oil (Cremophor EL) and ethanol. After dilution of Taxol in aqueous media paclitaxel tends to precipitate.

Post-marketing assessment of content and efficacy of preservatives in artemisinin-derived antimalarial dry suspensions for paediatric use.

Background: Artemisinin-derivative formulations are now widely used to treat falciparum malaria. However, the dry powder suspensions developed for children are few and/or are of poor quality. In addition to the active compound, the presence of a suitable preservative in these medicines is essential.

Quality control of active ingredients in artemisinin-derivative antimalarials within Kenya and DR Congo.

Objectives: Artemisinin-derivative drugs are widely used to treat Plasmodium falciparum malaria and very few studies have investigated the quality of these medicines in Africa. We analysed the active ingredient contents of artemisinin-derivative drugs marketed in Kenya and DR Congo.

Methods: We analysed tablets, capsules, dry suspensions and injections (IM) containing either artemether (AM), arteether (AE), artesunate (ARS) or dihydroartemisinin (DHA).

Investigation on the photostability of tretinoin in creams.

In this investigation, the photodegradation of some tretinoin cream formulations was evaluated. Several oils were selected to prepare the cream formulations: olive oil, maize oil, castor oil, isopropyl myristate and Miglyol 812. A solubility study showed that tretinoin is best soluble in castor oil (0.

Assay of artemether, methylparaben and propylparaben in a formulated paediatric antimalarial dry suspension.

Two HPLC-UV methods are described for the separate determination of artemether (AM) and the combined preservatives, methylparaben and propylparaben in a pharmaceutical dosage form. These analytes are contained in a dry suspension with a high amount of non-soluble excipients, some of which can interfere with the analysis. This makes their separation and analysis of the actives complex.

Comparison of free iodine as a function of the dilution of two commercial povidone-iodine formulations.

Binding studies by means of equilibrium dialysis on two different Povidone-lodine-solutions reveal that the amount of available iodine and free iodine is very different as such and after dilution. The free iodine concentration in the Braunol concentrate was found to be ca. 22 mg/L and in the iso-Betadine concentrate only ca.

Comparison of free and bound iodine and iodide species as a function of the dilution of three commercial povidone-iodine formulations and their microbicidal activity.

Equilibrium dialysis on povidone-iodine-solutions (Braunol, standardized Betadine and non-standardized iso-Betadine reveal that the amount of available iodine, free iodine, iodide and triiodide varies significantly both in the undiluted and diluted forms. These differences are reflected in the different bactericidal activity against Staphyloccus aureus as determined by the standard quantitative in vitro suspension test. The amount of available iodine is not an appropriate measure for an assessment of the microbicidal activity.

Inclusion complexation of diazepam with different cyclodextrins in formulations for parenteral use.

A parenteral formulation for the water-insoluble benzodiazepine diazepam was developed. Different cyclodextrins (CDs) suitable for parenteral injection: hydroxypropyl-beta-cyclodextrin (HP-beta-CD), hydroxy-propyl-gamma-cyclodextrin (HP-gamma-CD), sulfobutylether-7-beta-cyclodextrin (SBE-7-beta-CD) and maltosyl-beta-cyclodextrin (malt-beta-CD) were used as alternatives to cosolvents to increase solubility. The increase in solubility displayed a concentration dependency for the four CDs used.

Inclusion complexation of lorazepam with different cyclodextrins suitable for parenteral use.

The development of a parenteral lorazepam formulation, using cyclodextrins (CDs) as inclusion complexation agents, was investigated. CDs suitable for parenteral injection, i.e.

Experimental designed optimisation and stability evaluation of dry suspensions with artemisinin derivatives for paediatric use.

There is a great need for oral anti-malaria preparations especially for small children, which are easy to administer and keep their stability under tropical conditions. The purpose of this work was therefore to develop a dry suspension, containing one of the artemisinin derivatives, namely artesunate, artemether and dihydroartemisinin using fast wetting suspending agents, i.e.

Development of a reversed-phase thin-layer chromatographic method for artemisinin and its derivatives.

In this study a clear separation between seven analogues of artemisinin on thin-layer chromatography (TLC) is presented. The developed TLC method is carried out on a RP-C18 thin-layer plate using acetonitrile-water (50:25 v/v) as the mobile phase. Spots are visualized by derivatization with an acidified 4-methoxybenzaldehyde reagent in methanol-water.

Design of a dissolution system for the evaluation of the release rate characteristics of artemether and dihydroartemisinin from tablets.

As none of the pharmacopoeial dissolution methods are suitable to evaluate the release rate of artemether and dihydroartemisinin from tablets, a 'two-phase partition-dissolution' method, based on the one of [J. Pharm. Sci.

Preparation and in-vitro release rate of fentanyl-cyclodextrin complexes for prolonged action in epidural analgesia.

Fentanyl was complexed with cyclodextrin derivatives with the intention to obtain parenteral solutions able to provide prolonged analgesia following epidural administration. Three cylodextrins (CDs) suitable for parenteral use were used: hydroxypropyl-beta-cyclodextrin (HP-beta-CD), sulfobutylether-beta-cyclodextrin (SBE-7-beta-CD), and maltosyl-beta-cyclodextrin (malt-beta-CD). Analysis of fentanyl was done with HPLC-UV.

Densitometric thin-layer chromatographic determination of artemisinin and its lipophilic derivatives, artemether and arteether.

A thin-layer chromatograpy (TLC) method is developed to analyze artemisinin (AT) and its derivatives, artemether (AM) and arteether (AE), using a silica-gel plate with a mobile phase containing pure chloroform. After development, all products are visualized after dipping in a 4-methoxybenzaldehyde dipping reagent of 1% (v/v) in an acidic solution of sulphuric acid (98%, v/v) and acetic acid (96-98%, v/v) (respectively, 2% and 10%, v/v in alcohol-water, 60:30, v/v), presenting a purple color against a slightly colored background. This TLC system is quantitatively evaluated in terms of stability of the color, precision, accuracy, and calibration.

Validation of an HPLC method on short columns to assay ketoconazole and formaldehyde in shampoo.

An HPLC method to determine simultaneously ketoconazole and formaldehyde in an anti-dandruff shampoo, originally developed on a long column, was transferred to two short columns with similar stationary phase properties, but with a length of at the most 30% of the initial one. Using the conventional column as reference, the fast HPLC methods on the short columns were validated. The validation characteristics consisted of selectivity, linearity range, precision (repeatability and time-different intermediate precision), bias and robustness.

Physical and chemical evaluation of liposomes, containing artesunate.

As artesunate has a rapid onset of therapeutic effect and quick elimination, frequent administration is required, especially in the treatment of malaria. Such treatment courses led to bad patients' compliance, leading to high recrudescence rate. Therefore, slow release preparations seemed to be a logical approach in artesunate monotherapies, as can be developed with liposomal suspensions, especially for parenteral administration.