Biomedical subjects

Jean Paul Remon

Publications and source records attributed to Jean Paul Remon.

23 records · Page 2Linked to original sources

PubMed2002

Near-infrared FT-Raman spectroscopy as a rapid analytical tool for the determination of diltiazem hydrochloride in tablets.

This study was performed to develop a fast and reliable analytical method for the quantitative determination of diltiazem hydrochloride in tablets. HPLC is currently the preferred method, but is time consuming due to extensive sample preparation. FT-Raman spectroscopy was used to quantitatively analyse diltiazem hydrochloride in commercially available tablets (Tildiem) and in experimental tablets prepared at lab-scale. The percentage of diltiazem hydrochloride in each tablet was determined by calculating-after vector normalisation-the total peak area of the spectral band between 1625 and 1560 cm(-1). No spectral interference from tablet excipients was seen at this spectral band. After FT-Raman spectroscopy the same samples were analyzed based on the HPLC method described in the USP XXIV. The drug dosage per tablet obtained from the vibrational spectroscopy method correlated well with the results obtained using HPLC analysis for both the commercial tablets (HPLC: 63.57+/-0.13 mg; Raman: 63.28+/-0.26 mg (n=50)) and the experimental tablets (HPLC: 181.02+/-0.25 mg; Raman: 181.22+/-0.35 mg (n=50)). FT-Raman is a reliable alternative for the HPLC method to quantify the amount of diltiazem hydrochloride in tablets. The spectroscopic method is faster because it eliminates sample pre-treatment. Furthermore the FT-Raman method has an additional advantage of not requiring solvents.

Chromatography, High Pressure Liquid↗

PubMed2002

Scaling-up of a lactose wet granulation process in Mi-Pro high shear mixers.

The high shear wet granulation upscaling possibilities of a Pro-C-epT Mi-Pro 250 ml with a batch size of 40 g were investigated by down-scaling an alpha-lactose monohydrate wet granulation process from a Collette Gral 10 (8 l batch size) to a Pro-C-epT Mi-Pro with different bowl volumes of 5 l, and 1900, 900 and 250 ml. The wet granulation process was optimised in the Gral 10, next an octagonal design was build around the central point. Two process parameters, the impeller tip speed and the water content, were varied at three levels, which resulted in a two-factor three-level experimental design. alpha-Lactose monohydrate 200 M was granulated using a polyvinylpyrollidone K 30 (2.5% on dry material) binder solution. The granules were dried at 25 degrees C for 24 h, sieved and characterised. The granules were compressed to tablets. In all mixer volumes the used impeller tip speed range did not influence the granule or tablet properties. In all bowl volumes the influence of water concentration on actual yield, particle size distribution and granule friability was similar. All batch sizes resulted in tablets of similar quality. For the selected formulation the lab scale Mi-Pro high shear mixers with different bowl volumes could be used to determine the optimal process parameters and to scale up to the Collette Gral 10 pilot scale.

Lactose↗

PubMed2002

Development and in vitro evaluation of an enteric-coated multiparticulate drug delivery system for the administration of piroxicam to dogs.

The aim of the study was to develop enteric-coated pellets for the administration of piroxicam (a poorly water-soluble drug) to small animals in order to avoid local gastrointestinal irritation, one of the major side effects of nonsteroidal anti-inflammatory drugs after oral ingestion. Pellets were made by an extrusion-spheronization process. The influence of several excipients on the in vitro drug release was evaluated. Piroxicam release from the uncoated pellets was measured in phosphate buffer (pH 6.8) using the paddle dissolution method (USP XXIII). The enteric-coated pellets were tested in 0.1 N HCl and phosphate buffer, pH 6.8. The addition of sodium croscarmellose (Ac-Di-Sol) did not influence the piroxicam release from microcrystalline cellulose pellets. Sodium carboxymethyl starch (Explotab) increased the release from 30 to 65% at 45 min. The incorporation of sodium carboxymethyl cellulose on its own or as a co-processed blend with microcrystalline cellulose (Avicel RC 581 and CL 611) enhanced the release of piroxicam at 45 min from 30% (pure Avicel PH 101) to 95% (combination of Avicel PH 101 and CL 611 in a ratio of 1:3). Additional use of cyclodextrins had only a minor influence on the dissolution rate. An Eudragit L 30 D-55 and FS 30 D (6/4) film was applied to the core pellets (containing 2.5% (w/w) piroxicam and a combination of Avicel PH 101 and CL 611 in a ratio of 1:3) in order to obtain gastroresistant properties. The coated pellets retained their dissolution characteristics after compression into fast disintegrating tablets because waxy cushioning beads were added to minimize film damage.

Animals↗

PubMed2002

In vitro evaluation of the quality of essential drugs on the Tanzanian market.

We evaluated the in vitro availability and its stability under simulated tropical conditions of various formulations of four essential drugs marketed in Tanzania. We obtained 22 formulations (containing paracetamol, acetylsalicylic acid, chloroquine or sulphadoxine/pyrimethamine) from wholesale pharmacies in Dar es Salaam and the Medical Stores Department (Tanzania). The drug content, in vitro availability (dissolution) and its stability under simulated tropical conditions were determined using methods specified in the United States Pharmacopoeia (USP) 24 monograph of the respective drugs. All formulations passed the pharmacopoeia requirements for the drug content. However, seven formulations (three acetylsalicylic acid, two sulphadoxine/pyrimethamine and two paracetamol) failed to meet the USP 24 tolerance limits for dissolution. Another five formulations (three paracetamol and two chloroquine) failed to meet the dissolution tolerance limits after being subjected to an accelerated stability test under simulated tropical conditions (75% RH/40 degrees C) for 6 months. The study has demonstrated the presence on the Tanzanian market of essential drug formulations that met potency requirements and yet had unsatisfactory in vitro availability as they were not robust enough to withstand storage under simulated tropical conditions.

Drug Stability↗

PubMed2002

A new method to obtain and present complete information on the compatibility: study of its validity for eight binary mixtures of morphine with drugs frequently used in palliative care.

Parenteral administration of mixtures of morphine with other drugs has become common practice in palliative care. Such mixtures are sometimes found to be incompatible but compatibility data are scarce. An attempt was made to develop a quick and simple investigation strategy to obtain complete information on the compatibility of two drugs. This strategy was then used to study the physical and chemical compatibility of morphine HCl with alizapride HCl, atropine sulphate, dexamethasone sodium phosphate, hyoscine butylbromide, metoclopramide HCl, octreotide lactate, ranitidine HCl and hyoscine hydrobromide. These compatibility data are presented in such a way that they are easy to use in clinical practice. The investigation strategy outlined here allows the collection of complete information on the compatibility of morphine with another drug by studying a limited number of carefully selected mixtures per combination. The mixtures to be studied are selected using a scheme in which all possible mixtures prepared by mixing morphine solutions of varying concentrations with a drug solution in different volume ratios can be visualized. Applying this strategy to the eight combinations revealed, except for ranitidine HCl, no physical (visual) or chemical (HPLC; >90%) incompatibility in any of the mixtures studied for seven days at 22 and 32 degrees C. This indicates that all possible mixtures of these drug solutions with morphine HCl are compatible. For the combination with ranitidine incompatibility was observed only when using morphine HCl solutions containing >40 mg/ml and at certain ratios (drug/morphine HCl [D/M]: 4/42, 10/6 and 8/8, v/v), but all physically compatible mixtures were chemically stable (>90%). Studying extra mixtures in addition to those required to be studied according to the strategy revealed no discrepancies for any of the eight combinations studied. Adaptation of the layout of the scheme and the design of a decision tree resulted in an easy tool to check compatibility in daily practice. The scheme designed in this study is a useful tool for research and for daily practice. It simplifies and thereby encourages investigation of the compatibility of drugs. The availability of data on the physical as well as chemical compatibility in daily practice will contribute to a better quality of the mixtures used in palliative care and help to avoid complications and inadequate symptom control.

Analgesics, Opioid↗