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Aburuz SM, McElnay JC, Millership JS, Andrews WJ, Smyth S. Factors affecting self-care activities, postprandial plasma glucose and HbA1c in patients with type 2 diabetes. International Journal of Pharmacy Practice 2011. [DOI: 10.1111/j.2042-7174.2002.tb00704.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Abstract
Focal points
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Affiliation(s)
- S M Aburuz
- Clinical and Practice Research Group, School of Pharmacy, Queens University Belfast, 97 Lisburn Road, Belfast BT9 7BL
| | - J C McElnay
- Clinical and Practice Research Group, School of Pharmacy, Queens University Belfast, 97 Lisburn Road, Belfast BT9 7BL
| | - J S Millership
- Clinical and Practice Research Group, School of Pharmacy, Queens University Belfast, 97 Lisburn Road, Belfast BT9 7BL
| | - W J Andrews
- Clinical and Practice Research Group, School of Pharmacy, Queens University Belfast, 97 Lisburn Road, Belfast BT9 7BL
| | - S Smyth
- Clinical and Practice Research Group, School of Pharmacy, Queens University Belfast, 97 Lisburn Road, Belfast BT9 7BL
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Abstract
AIMS To explore awareness and views of the general public on unlicensed use of medicines in children and on the participation of children in clinical trials. METHODS Members of the public completed a questionnaire survey administered by face-to-face interview in public areas in N. Ireland. The main outcome measures were the views on unlicensed use of medicines in children and on clinical trials in children. RESULTS One thousand participants (59.2% female) took part; 610 were parents. Most participants (86%) had no previous knowledge about unlicensed use of medicines in children. Being a parent did not influence this nor did being a parent of a child who suffered from a health problem (P > 0.05). Most participants (92%) felt that parents should be told about unlicensed use of medicines, with the doctor most frequently selected as the person who should inform parents. At the outset, only 1.8% of participants felt that the use of medicines in children was unsafe. However, having been informed about unlicensed use of medicines, this proportion increased dramatically (62.4%; P < 0.001). Views on whether participants would enter a child of their own into a clinical trial varied according to the health status of the child (P < 0.05) i.e. a child in good health (3.9%) vs a child with a life-threatening condition (41.9%). CONCLUSIONS There is limited public knowledge of unlicensed use of medicines in children and a general reluctance to involve children in clinical trials unless the child to be involved has a life-threatening condition.
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Affiliation(s)
- T L Mukattash
- Clinical and Practice Research Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
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Sandall JM, Millership JS, Collier PS, McElnay JC. Development and validation of an HPLC method for the determination of spironolactone and its metabolites in paediatric plasma samples. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 839:36-44. [PMID: 16510319 DOI: 10.1016/j.jchromb.2006.02.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Revised: 02/07/2006] [Accepted: 02/11/2006] [Indexed: 11/26/2022]
Abstract
An HPLC method has been developed and validated for the determination of spironolactone, 7 alpha-thiomethylspirolactone and canrenone in paediatric plasma samples. The method utilises 200 microl of plasma and sample preparation involves protein precipitation followed by Solid Phase Extraction (SPE). Determination of standard curves of peak height ratio (PHR) against concentration was performed by weighted least squares linear regression using a weighting factor of 1/concentration2. The developed method was found to be linear over concentration ranges of 30-1000 ng/ml for spironolactone and 25-1000 ng/ml for 7 alpha-thiomethylspirolactone and canrenone. The lower limit of quantification for spironolactone, 7 alpha-thiomethylspirolactone and canrenone were calculated as 28, 20 and 25 ng/ml, respectively. The method was shown to be applicable to the determination of spironolactone, 7 alpha-thiomethylspirolactone and canrenone in paediatric plasma samples and also plasma from healthy human volunteers.
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Affiliation(s)
- J M Sandall
- Clinical and Practice Research Group, School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97, Lisburn Road, Belfast BT9 7BL, UK
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Millership JS, Parker C, Donnelly D. Ratio spectra derivative spectrophotometry for the determination of furosemide and spironolactone in a capsule formulation. ACTA ACUST UNITED AC 2005; 60:333-8. [PMID: 15848209 DOI: 10.1016/j.farmac.2005.02.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2004] [Accepted: 02/01/2005] [Indexed: 10/25/2022]
Abstract
The determination of furosemide and spironolactone in a capsule formulation has been investigated using techniques such as Vierordt's method and derivative spectroscopy dA/d lambda and d2A/d lambda2 applying the zero-crossing technique following reported methods. In our hands, using standard mixtures, these methods gave unreliable results. We have therefore investigated the use of ratio spectra derivative spectrophotometry for this determination. The technique of ratio spectra derivative spectrophotometry was developed in 1990, and has recently been used for a number of analyses of co-formulated products. The method was applied to the analysis of standard mixtures of the two drugs and the combined contents of 20 capsules resulting in values (mean +/- standard deviation) of 102.1 +/- 1.9% and 101.4 +/- 4.0% of the stated content for furosemide and spironolactone, respectively. Similarly, the analysis of individual capsules resulted in values of 101.5 +/- 1.6% and 102.2 +/- 1.4% of the stated content for furosemide and spironolactone, respectively.
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Affiliation(s)
- J S Millership
- Clinical and Practice Research Group School of Pharmacy Queen's University, Belfast Medical Biology Centre, 97 Lisburn Road Belfast BT9 7BL, Northern Ireland.
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Abstract
Ethosuximide is a chiral drug substance primarily indicated for the treatment of absence seizures. This drug is used clinically as the racemate. The human urinary metabolites of ethosuximide (I) have been studied using chiral gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The metabolites identified were the previously reported unchanged ethosuximide (I) enantiomers, all four stereoisomers of 2-(1-hydroxyethyl)-2-methylsuccinimide (II), and the four stereoisomers of 2-ethyl-3-hydroxy-2-methylsuccinimide (III). Through chemical derivatization methodology and GC/MS (using electron impact ionization [EI] and chemical ionization [CI] techniques) two enantiomers of a previously unreported metabolite of ethosuximide, 2-ethyl-2-hydroxymethylsuccinimide (VI), have been identified.
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Affiliation(s)
- J S Millership
- Clinical and Practice Research Group, The School of Pharmacy, Medical Biology Centre, The Queen's University of Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland.
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Smyth JM, Collier PS, Darwish M, Millership JS, Halliday HL, Petersen S, McElnay JC. Intravenous indometacin in preterm infants with symptomatic patent ductus arteriosus. A population pharmacokinetic study. Br J Clin Pharmacol 2004; 58:249-58. [PMID: 15327584 PMCID: PMC1884560 DOI: 10.1111/j.1365-2125.2004.02139.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
AIMS To characterize the population pharmacokinetics of indometacin in preterm infants with symptomatic patent ductus arteriosus and to investigate the influence of various factors on the response to treatment. METHODS Data were collected from 35 infants (gestational age 25-34 weeks; postnatal age 1-77 days) in neonatal units in Belfast and Copenhagen. Infants received an initial course of up to three doses of intravenous indometacin (0.1-0.2 mg kg(-1)) as considered appropriate by the treating physician. For those infants who did not respond to therapy or in whom the ductus reopened, a second course was sometimes given. Population analysis of the 185 plasma concentrations obtained was conducted using NONMEM and pharmacokinetic and demographic differences between responders and nonresponders were compared. RESULTS The concentration-time course of indometacin was best described by a one-compartment model. The final population parameter estimates of clearance (CL) and volume of distribution (V) (standardized to the median weight of 1.17 kg) were 0.00711 l h(-1) and 0.266 l, respectively. CL increased from birth by approximately 3.38% per day and V by approximately 1.47% per day. Concomitant digoxin therapy resulted in a 30% decrease in V. Interindividual variability in CL and V was 41% and 21%, respectively. Interoccasion variability for CL was 43%. Residual variability corresponded to a standard deviation of 0.148 mg l(-1). Closure occurred in 75% of infants with a plasma concentration > or = 0.4 mg l(-1) 24 h after the last dose. CONCLUSIONS Dosing regimens for indometacin should take into account the weight and postnatal age of the infant and any concomitant digoxin therapy. The population estimates can be used to determine typical values of CL and V allowing the prediction of individualized doses of indometacin that should increase the probability of achieving a 24 h plasma concentration > or = 0.4 mg l(-1). Although the pharmacokinetic estimates will be affected by both interindividual and within-individual variation, it is anticipated that this approach will decrease the variability of exposure and optimize treatment outcome.
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Affiliation(s)
- J M Smyth
- Clinical and Practice Research Group, School of Pharmacy, Queen's University, Belfast, UK
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Hare LG, Mitchel DS, Millership JS, Collier PS, McElnay JC, Shields MD, Carson DJ, Fair R. Liquid chromatographic determination including simultaneous “on-cartridge” separation of ranitidine cisapride drug combinations from paediatric plasma samples using an automated solid-phase extraction procedure. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 806:263-9. [PMID: 15171937 DOI: 10.1016/j.jchromb.2004.04.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2004] [Revised: 04/05/2004] [Accepted: 04/06/2004] [Indexed: 10/26/2022]
Abstract
HPLC methodology was investigated for the simultaneous determination of cisapride and ranitidine in small volume paediatric plasma samples. Such a simultaneous determination proved difficult due to the small sample volumes, the low concentrations of the drugs and the different log P values of the two compounds. The two drugs and their respective internal standards were separated "on-cartridge" using HLB Solid Phase Extraction cartridges and the samples quantified by individual HPLC methodologies. The technique has been applied successfully to 60 paediatric plasma samples containing both cisapride and ranitidine.
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Affiliation(s)
- L G Hare
- Children's Medicines Research Group, The School of Pharmacy, The Queen's University of Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT97BL, Northern Ireland, UK
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Hare LG, Millership JS, Collier PS, McElnay JC, Carson DJ, Shields MS. The use of polymeric solid phase extraction and HPLC analysis for the determination of ranitidine in routine plasma samples obtained from paediatric patients. J Pharm Pharmacol 2001; 53:1265-72. [PMID: 11578109 DOI: 10.1211/0022357011776559] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A sensitive HPLC method for the determination of ranitidine in small-volume (0.5 mL) paediatric plasma samples is described. Plasma samples were extracted using a simple, rapid solid phase extraction (SPE) technique developed using disposable copolymer packed SPE cartridges. Chromatographic separation was achieved by reverse-phase HPLC with isocratic elution using a microBondapak C18 column and a phosphate buffer (10 mM, pH 3.75)-acetonitrile (87:13 v/v) mobile phase with UV detection at 313 nm. The HPLC system exhibited linearity in the range 8-800 ng mL(-1). Intraday % CV and % bias values were in the range 1.28-8.09% (% bias -4.33 to -0.87) and interday % CV and % bias values were in the range 0.73-15.28% (% bias -1.80 to + 1.65). The limits of detection and quantitation obtained were 2 ng mL(-1) and 8 ng mL(-1), respectively, and ranitidine extraction recoveries from plasma ranged from 92.30 to 103.88%. In this study, the developed HPLC and SPE methodologies have been successfully applied to the determination of ranitidine concentrations in 68 paediatric plasma samples. The sampled population was drawn from patients already receiving the study drug therapeutically. Patients recruited had received ranitidine by two main routes - oral and intravenous. The plasma concentrations of ranitidine encountered in paediatric samples following oral or intravenous administration of a range of prescribed doses are presented graphically. These profiles are based on analysis of the first 68 plasma samples obtained from the first 35 patients recruited to the study receiving ranitidine by the oral or intravenous route.
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Affiliation(s)
- L G Hare
- The School of Pharmacy, The Queen's University of Belfast, Medical Biology Centre, Northern Ireland, UK
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Millership JS, Hare LG, Farry M, Collier PS, McElnay JC, Shields MD, Carson DJ. The use of hydrophilic lipophilic balanced (HLB) copolymer SPE cartridges for the extraction of diclofenac from small volume paediatric plasma samples. J Pharm Biomed Anal 2001; 25:871-9. [PMID: 11377070 DOI: 10.1016/s0731-7085(01)00367-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The extraction of diclofenac from spiked aqueous and plasma samples by liquid-liquid extraction (LLE) and solid phase extraction (SPE) methods is compared. The SPE methodology utilised a hydrophilic lipophilic balanced (HLB) copolymer as the extraction phase. Using a literature HPLC method, a calibration curve for diclofenac was constructed in the range 1.0-50.0 microg/ml. Diclofenac spiked samples (aqueous and plasma) were extracted by LLE and SPE methodologies. The SPE resulted in higher extraction efficiencies (mean 94.9%) than the LLE (mean 78.9%) with %R.S.D.s similar in both methods (3.2 vs. 2.1%, respectively). The SPE method was suitable for the extraction of diclofenac from small volume paediatric plasma samples.
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Affiliation(s)
- J S Millership
- The School of Pharmacy, The Queen's University of Belfast, Medical Biology Centre, 97 Lisburn Road, BT9 7BL, Northern Ireland, Belfast, UK
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Mifsud J, Millership JS, Collier PS, Morrow R, Hamilton JT, McRoberts WC. Quantification of urinary excretion of ethosuximide enantiomers and their major metabolites in the rat. Biopharm Drug Dispos 2001; 22:129-36. [PMID: 11745915 DOI: 10.1002/bdd.265] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A chiral gas chromatographic assay has been developed for quantitative analysis of ethosuximide and its major metabolites in rat urine. The extraction procedure was found to be precise and reproducible. Recovery was in the range of 94-98%, intraday CV(%) was 0.92% for (S)-ethosuximide (50 microg/ml) and 0.51% for (R)-ethosuximide (50 microg/ml). Interday CV(%) was 1.12% for (S)-ethosuximide and 0.72% for (R)-ethosuximide. The limit of detection was determined to be around 0.01 microg/ml for each enantiomer. Following administration of rac-ethosuximide by i.v., i.p. and oral routes, unchanged ethosuximide was detected in urine up to 72 h after drug administration. The appearance of all detected metabolites occurred within 24 h of drug administration. Significantly more (S)-ethosuximide was excreted unchanged than (R)-ethosuximide with all three routes studied. A substantial amount of the drug was eliminated as the 2-(1-hydroxyethyl)-2-methylsuccinimide (2 pairs of diastereoisomers). Much less drug was eliminated as the 2-ethyl-3-hydroxy-2-methylsuccinimide with only one diastereoisomer observed. Examination of the one pair of diastereoisomers of 2-(1-hydroxyethyl)-2-methylsuccinimide that was resolved showed preferential excretion of one isomer. Comparison of both pairs of diastereoisomers showed that one pair was formed in preference to the other with a ratio of approximately 0.8:1. It is concluded that stereoselective metabolism of ethosuximide occurs.
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Affiliation(s)
- J Mifsud
- School of Pharmacy, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK
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Abstract
A chiral gas chromatographic assay previously developed for quantitative analysis of ethosuximide and its major metabolites in rat urine has been adapted for the analysis of the drug in plasma. Ethosuximide, both as a racemic mixture and as the individual enantiomers, was administered to conscious rats by the intravenous (i.v.) and intraperitoneal (i.p.) routes. Pharmacokinetic parameters were estimated using standard non-compartmental methods. Comparison of the pharmacokinetic parameters of (S)-ethosuximide and (R)-ethosuximide showed that total body clearance of (R)-ethosuximide was significantly larger than that of (S)-ethosuximide and that elimination half-life was significantly shorter following administration of both 40 mg i.v. and i.p. doses, indicating that there is stereoselective elimination of ethosuximide. However, no significant differences were found between apparent volumes of distribution. In addition, no significant differences were found for either enantiomer between the estimates of the pharmacokinetic parameters obtained following administration as the individual enantiomer and as a constituent of the racemic mixture. This indicates that, at the doses studied, the preferential faster elimination of (R)-ethosuximide is not dependent upon the presence of the (S)-enantiomer. Also, for each enantiomer, the lack of any significant difference between estimates of clearance when administered as part of a racemic mixture and when administered separately indicates that neither enantiomer affects the clearance of the other.
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Affiliation(s)
- J Mifsud
- School of Pharmacy, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK
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Millership JS, McKervey MA, Russell JA. Complexation and chromatographic studies involving water soluble calixarenes and nitrophenols. Chromatographia 1998. [DOI: 10.1007/bf02467711] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
In vitro experiments to investigate possible stereoselective aspects of the topical administration of ibuprofen have been conducted. Incubation of ibuprofen with rat skin homogenates in the presence of coenzyme A, ATP, and magnesium provided no evidence for the formation of ibuprofenyl coenzyme A (the initial intermediate in the metabolic inversion of [R]- to [S]-ibuprofen). Similar incubation studies gave no indication of a change in the enantiomeric ratios of ibuprofen over the time course of the experiments. Percutaneous penetration studies of ibuprofen gel through porcine skin indicated that the ibuprofen enantiomer levels in the reservoir solutions were consistent with racemic ibuprofen having traversed the skin with no metabolic inversion. These results suggest that, in the models studied, skin metabolism does not result in the chiral inversion of (R)- to (S)-ibuprofen and that the topical administration of ibuprofen will result in the delivery of 50% "isomeric ballast."
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Affiliation(s)
- J S Millership
- School of Pharmacy, Queen's University of Belfast, Northern Ireland
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Brereton RG, Millership JS, Favell D, Harvey DJ, Beddows CG, Threlfall T. Book and video reviews. Analyst 1996. [DOI: 10.1039/an996210129n] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
Ethosuximide is a chiral drug substance primarily indicated for the treatment of absence seizures. This drug is used clinically as the racemate. The urinary metabolites of ethosuximide (following i.p. administration of the racemate or individual enantiomers to rats) have been studied using chiral gas chromatography (GC) and gas chromatography-mass spectroscopy (GCMS). The metabolites identified were unchanged ethosuximide enantiomers, all four stereoisomers of 2-(1-hydroxyethyl)-2-methylsuccinimide, and a single stereoisomer of 2-ethyl-3-hydroxy-2-methylsuccinimide [derived from (R)-ethosuximide]. Preliminary quantitative studies indicate a degree of stereoselectivity in the fate of ethosuximide since the ratio of (R)- to (S)-ethosuximide in the urine was found to be 0.77:1 (0-24 h sample), 0.64:1 (24-48 h sample), and 0.83:1 (48-72 h sample). This would suggest that the (R)-isomer is preferentially metabolised. Results obtained following the administration of individual enantiomers of ethosuximide indicate that the 2-(1-hydroxyethyl)-2-methylsuccinimide diastereoisomers derived from (R)-ethosuximide are produced in approximately equal proportions [ratio 1.05:1 (0-24 h sample), 1.10:1 (24-48 h sample)], whilst those from (S)-ethosuximide are produced in unequal proportions [ratio 1.65:1 (0-24 h sample), 1.74:1 (24-48 h sample)].
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Affiliation(s)
- J S Millership
- School of Pharmacy, Queen's University of Belfast, Medical Biology Centre, Northern Ireland
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Millership JS. Interference of mandelic acid with the determination of homatropine hydrobromide by second-order derivative spectroscopy. J Pharm Biomed Anal 1994; 12:1199-203. [PMID: 7803572 DOI: 10.1016/0731-7085(94)e0038-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- J S Millership
- School of Pharmacy, Queen's University of Belfast, Medical Biology Centre, UK
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Abstract
The metabolism of the antiepileptic drug ethosuximide (3-ethyl-3-methylpyrollidine-2,5-dione) (I) in animals and humans is reviewed. Chiral aspects of the metabolism of ethosuximide are discussed. Clarification of the precise nature of the hydroxymetabolites of ethosuximide is presented.
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Abstract
Initial results of a comparative survey of commonly used chiral drugs are presented. The survey considered the differences between drugs used in 1982 with those in use in 1991. Two major conclusions were reached: the use of single isomer chiral drugs had increased from 31.1% in 1982 to 34.3% in 1991 and the proportion of synthetic single isomer chiral drugs available in 1991 was considerably greater than in 1982.
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Affiliation(s)
- J S Millership
- School of Pharmacy, Queen's University of Belfast, Medical Biology Centre, Northern Ireland
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Affiliation(s)
- T A Dawson
- Department of Dermatology, Craigavon Area Hospital, Northern Ireland, UK
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Abstract
The literature relating to the determination of chlorpromazine, related impurities and degradation products in pharmaceutical preparations is reviewed. Related impurities and degradation products are defined and official methods of analysis are described. Analytical methods including gravimetric, titrimetric ultraviolet-visible spectrophotometric, chromatographic and electrochemical techniques are discussed.
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Affiliation(s)
- L F Chagonda
- Department of Pharmacy, Queen's University of Belfast, UK
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Karim EF, Millership JS, Temple DJ, Woolfson AD. An investigation of the metabolism of S-carboxymethyl-L-cysteine in man using a novel HPLC-ECD method. Eur J Drug Metab Pharmacokinet 1988; 13:253-6. [PMID: 3243319 DOI: 10.1007/bf03190087] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The metabolism of an oral dose of S-carboxymethyl-L-cysteine (SCMC) in man has been studied; the quantitative determination of SCMC, S-methyl-L-cysteine (SMC) and their sulphoxide metabolites (SCMCO and SMCO), in urine, was carried out using high performance liquid chromatography (HPLC) with electrochemical detection (ECD); the possibility of stereospecific sulphoxidation was investigated.
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Affiliation(s)
- E F Karim
- Department of Pharmacy, Queen's University of Belfast, Northern Ireland
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Millership JS, Shanks ML. Prodrugs utilizing organosilyl derivation: an investigation of the long-term androgenic and myotrophic activities of silyl derivatives of testosterone. J Pharm Sci 1988; 77:116-9. [PMID: 3361425 DOI: 10.1002/jps.2600770205] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The long-term androgenic and myotrophic activities of dimethylditestosteroxysilane and diphenylditestosteroxysilane were studied and compared with the activities of testosterone propionate and testosteroxytrimethylsilane. The testing was carried out in vivo, using castrated male rats, over a 50-d period. Dimethylditestosteroxysilane and diphenylditestosteroxysilane were shown to exhibit both myotrophic activity and androgenic activity. In the early stages of the study, dimethylditestosteroxysilane displayed myotrophic activity with no corresponding androgenic activity. The results presented indicate that these silyl ethers act as latentiated derivatives of testosterone.
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Affiliation(s)
- J S Millership
- Department of Pharmacy, Queen's University of Belfast, Northern Ireland
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Chagonda LF, Millership JS. High-performance liquid chromatographic determination of chlorpromazine and its degradation products in pharmaceutical dosage forms: a stability-indicating assay. Analyst 1988; 113:233-7. [PMID: 3377169 DOI: 10.1039/an9881300233] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Abstract
The sorption of the antifungal drug miconazole onto the plastics of infusion bags and intravenous administration sets has been investigated. HPLC methodology was applied for the determination of miconazole concentrations. The results obtained indicate that the sorption of miconazole is low and is unlikely to result in significant loss of clinical efficacy.
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Affiliation(s)
- A G McGookin
- Department of Pharmacy, Queen's University of Belfast, Medical Biology Centre, Northern Ireland
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Woolfson AD, Millership JS, Karim EF. Determination of the sulphoxide metabolites of S-carboxymethyl-L-cysteine by high-performance liquid chromatography with electrochemical detection. Analyst 1987; 112:1421-5. [PMID: 3434821 DOI: 10.1039/an9871201421] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Millership JS. A report on an initial comparative study of two methods for the determination of glutaraldehyde. J Clin Pharm Ther 1987; 12:33-8. [PMID: 3130383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Two methods for the determination of aqueous glutaraldehyde, a gas chromatographic method and an ultraviolet spectrophotometric difference method, were compared. The two methods gave similar results for glutaraldehyde concentration determination when investigating undegraded samples. However, the ultraviolet method gave lower values than the gas chromatographic method when degraded samples were studied. A possible source of these discrepancies is discussed.
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Affiliation(s)
- J S Millership
- Department of Pharmacy, Queen's University of Belfast, Northern Ireland
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Scott EM, Gorman SP, Millership JS, Wright LR. Effect of miconazole and clotrimazole on K+ release and inhibition of ergosterol biosynthesis in Trichophyton mentagrophytes and related ultrastructural observations. J Antimicrob Chemother 1986; 17:423-32. [PMID: 3710956 DOI: 10.1093/jac/17.4.423] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Measurement of K+ ions in extracellular fluids was used to provide evidence of direct membrane damage induced by miconazole and clotrimazole in Trichophyton mentagrophytes mycelium. K+ release from mycelium treated with high concentrations of drug was extensive, although leakage occurred more rapidly and to a greater extent with miconazole than with clotrimazole. Cells treated with fungicidal concentrations of drug were completely necrotic. The effect of miconazole was concentration dependent. A reduction in ergosterol levels was evident after 5 h treatment with miconazole. Further reduction in ergosterol concentration was demonstrated after 24 h with fungistatic concentrations of drug and was a concentration dependent effect. Fungistatic concentrations of miconazole also induced ultrastructural changes in mycelium, which were apparent within 5 h of treatment and became more pronounced after 24 h. Clotrimazole also reduced ergosterol levels and affected ultrastructure of mycelium. The plasma membrane in particular was affected by both these drugs.
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Abstract
Kier & Hall (1976) demonstrated that a relationship existed between molecular connectivity and Log P (the Log of the octanol/water partition coefficient) for several classes of compounds and also for the combined classes. This work utilized a number of Log P values calculated using Pi values. We have reinvestigated this relationship using experimentally determined Log P values. The results confirm Kier & Hall's findings although different connectivity indices are brought into the equations.
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Boyd JC, Millership JS, Woolfson AD. A comparison of log P and molecular connectivity in the structure-activity analysis of some antimicrobial agents. J Pharm Pharmacol 1982; 34:158-61. [PMID: 6121892 DOI: 10.1111/j.2042-7158.1982.tb04213.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Several congeneric series of antimicrobial agents previously studied by Hansch analysis have been investigated using molecular connectivity as the descriptor of molecular structure. In all cases connectivity gave comparable or improved correlations compared with log P, particularly where the pattern of molecular substitution was more complex. It was concluded that the use of computer-generated connectivity terms had advantages over calculated log P values in its ease of application and should be considered at least for initial screening of structure-activity data.
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Abstract
The relation between gas chromatographic retention parameters and molecular connectivity has been investigated for several series of compounds including hydrocarbons, compounds containing oxygen functional groups (esters, aldehydes, ketones, alcohols and ethers) and drug molecules., With the oxygenated compounds good correlation was observed with the first order valence connectivity index, whilst for the other groups multiparameter equations were required for satisfactory correlation. The effect of column to column variation within a series was also investigated.
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Millership JS, Woolfson AD. A study of the relationship between gas chromatographic retention parameters and molecular connectivity [proceedings]. J Pharm Pharmacol 1979; 31 Suppl:44P. [PMID: 42719 DOI: 10.1111/j.2042-7158.1979.tb11592.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Abstract
The recently developed topological index, molecular connectivity (chi), has been correlated using multiple regression analysis with gas chromatographic retention time (Rt) for various series of compounds. For saturated and unsaturated aliphatic hydrocarbons, and aliphatic aldehydes, good correlation with log Rt was achieved by one-parameter linear equations in terms of the first-order conncectivity index. (1chi). The equation for aliphatic alcohols required an additional parameter, the valence connectivity (vchi) for satisfactory correlation. One-parameter equations using 1chi also good correlation with log Rt for three series of drug molecules, amphetamines, barbiturates and phenothiazines. In all cases the equations generated gave good agreement between calculated and observed log Rt values.
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Millership JS, O'Hare RE. Trimethylsilylethers of enthinylalcohols as latentiated drugs [proceeding]. J Pharm Pharmacol 1976; 28 Suppl:14P. [PMID: 12287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Garner GV, Mobbs DB, Suschitzky H, Millership JS. Syntheses of heterocyclic compounds. Part XXIV. Cyclisation studies with ortho-substituted arylcarbene and arylnitrene precursors. ACTA ACUST UNITED AC 1971. [DOI: 10.1039/j39710003693] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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