Kinetic study of the hydrolysis of pancuronium bromide. 1. Specific acid catalysis

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Kinetic study of hydrolysis of pancuronium-bromide .3. media effects

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Thin-layer chromatography of pancuronium bromide and its hydrolysis products

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In situ quantitation of pancuronium bromide and hydrolysis products by spectrodensitometry of thin-layer chromatograms

A method is described for densitometric evaluation of pancuronium and hydrolysis products, separated by thin layer chromatography. By adaptation of the detection procedure, iodine vapour can be used as visualization reagent. Quantitative determination in relative amounts is possible, because the desorption process of iodine from the spots follows a first order reaction. Precision and accuracy of the method are acceptable.status: publishe

Comparative-evaluation of maltose as excipient for direct compression

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The biopharmaceutical aspects of nasal mucoadhesive drug delivery

Nasal drug administration has frequently been proposed as the most feasible alternative to parenteral injections. This is due to the high permeability of the nasal epithelium, allowing a higher molecular mass cut-off at approximately 1000 Da, and the rapid drug absorption rate with plasma drug profiles sometimes almost identical to those from intravenous injections. Despite the potential of nasal drug delivery, it has a number of limitations. In this review, the anatomy and physiology of the nasal cavity, as well as ciliary beating and mucociliary clearance as they relate to nasal drug absorption, are introduced. The rationale for nasal drug delivery and its limitations, some factors that influence nasal drug absorption, and the experimental models used in nasal drug delivery research are also reviewed. Nasal mucoadhesion as a promising method of nasal absorption enhancement is discussed, and factors that influence mucoadhesion, as well as safety of nasal mucoadhesive drug delivery systems are reviewed in detail. Nasal drug administration is presently mostly used for local therapies within the nasal cavity. Anti-allergic drugs and nasal decongestants are the most common examples. However, nasal drug administration for systemic effects has been practised since ancient times. Nasally-administered psychotropic drugs by native Americans, the use of tobacco snuffs, and nasal administration of illicit drugs such as cocaine are all well known (Illum & Davis 1992). Nowadays, the nasal cavity is being actively explored for systemic administration of other therapeutic agents, particularly peptides and proteins (Illum 1992; Edman & Björk 1992), as well as for immunization purposes (Lemoine et al 1998). To better understand the basis for nasal drug absorption and factors that can influence it, a brief review of the anatomy and physiology of the nose is appropriate.status: publishe

Comparison of biological indicators for ethylene-oxide sterilization monitoring

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Dissolution testing of artemisinin solid oral dosage forms

Dissolution can best be described as a tool that can provide valuable information about the bioavailability of a drug product. But to obtain a good overall correlation with in vivo data, the presence of sink conditions is an essential requirement in the dissolution tests. The flow-through cell method has been recommended to be a dissolution method that most satisfactorily fulfils this requirement for poorly water soluble drugs. The present article demonstrates that in case of artemisinin, a hydrophobic compound used in high dose per tablet or capsule, even the flow-through cell method does not guarantee the presence of sink conditions during the total duration of the experiments.status: publishe

Microencapsulation of apomorphine HCl with gelatin

Microspheres of apomorphine HCl were prepared, with gelatin as polymer coating material, using the emulsification solvent extraction method. The microencapsulation efficiency, particle size and release profile were compared to those of riboflavin sodium phosphate (RSPh). An efficiency of approximately 95% was obtained with RSPh while the quantity of acetone and ether used as preparative solvents resulted in low microencapsulation efficiency for apomorphine HCl. A reduction of the volumes of these solvents improved the efficiency by a factor of more than two but the mean particle size range became slightly higher due to agglomeration as compared to the mean particle size when more solvent was used. A faster release rate was found for RSPh than for apomorphine HCl, according their water solubilities. Crosslinking of gelatin-RSPh microspheres with formaldehyde and glutharaldehyde (10 and 20% v/v for 1, 6, and 24 h) did not extend the duration of release of RSPh and reduced the quantity of drug microencapsulated. (C) 1997 Elsevier Science B.V.status: publishe

Comparative study on xanthan gum and hydroxypropylmethyl cellulose as matrices for controlled-release drug delivery .1. Compaction and in vitro drug release behaviour

A comparative investigation has been undertaken to assess the performance of xanthan gum (XG) and hydroxypropylmethyl cellulose (HPMC) as hydrophilic matrix-forming agents in respect of compaction characteristics and in vitro drug release behaviour. The overall compaction characteristics are found to be quite similar to each other and typical of polymer behaviour. But the flow characteristics are different, i.e., XG is more readily flowable than HPMC. The observed difference in drug release profiles between these two potential excipients are explored and explained by the difference in their hydrophilicity and subsequent hydration properties.status: publishe