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Optimization study on the formulation of roxithromycin dispersible tablet using experimental design.

This study set out to improve the physical and pharmaceutical characteristics of the present formulation using an appropriate experimental design. The work described here concerns the formulation of the dispersible tablet applying direct compression method containing roxithromycin in the form of coated granules. In this study 2(3) factorial design was used as screening test model and Central Composite Design (CCC) associated with response surface methodology was used as optimization study model to develop and to optimize the proper formulation of roxithromycin dispersible tablet. The three independent variables investigated were functional excipients like binder (X1), disintegrant (X2) and lubricant (X3). The effects of these variables were investigated on the following responses: hardness (Y1), friability (Y2) and disintegration time (Y3) of tablet. Three replicates at the center levels of the each design were used to independently calculate the experimental error and to detect any curvature in the response surface. This enabled the best formulations to be selected objectively. The effect order of each term to all response variable was X3> X2> X1> X1*X2> X2*X2> X2*X3> X3*X3> X1*X3> X1*X1 and model equations on each response variables were generated. Optimized compositions of formula were accordingly computed using those model equations and confirmed by following demonstration study. As a result, this study has demonstrated the efficiency and effectiveness of using a systematic formulation optimization process to develop the tablet formulation of roxithromycin dispersible tablet with limited experiment.

Anti-Bacterial Agents↗

Effect of solvents on physical properties and release characteristics of monolithic hydroxypropylmethylcellulose matrix granules and tablets.

Effect of solvents on physical characteristics and release characteristics of monolithic acetaminophen (APAP) hydroxypropylmethylcellulose (HPMC) matrix granules and tablets were examined. Various types and amounts of solvents were employed for granulation and cOAting. APAP and other excipients were mixed and were then wet-granulated in a high-speed mixer. The dried granules were then directly compressed and film-coated with low viscosity grade HPMC. As the amount of water increased, the size of granules also increased, showing more spherical and regular shape. However, manufacturing problems such as capping and lamination in tableting occurred when water was used alone as a granulating solvent. The physical properties of HPMC matrix granules were not affected by the batch size. The initial release rate as well as the amount of APAP dissolved had a tendency to decrease as the water level increased. Addition of nonaqueous solvent like ethanol to water resulted in good physical properties of granules. When compared to water/ethanol as a coating solvent, the release rate of film-coated HPMC matrix tablets was more sensitive to the conditions of coating and drying in methylene chloride/ethanol. Most of all, monolithic HPMC matrix tablet when granulated in ethanol/water showed dual release with about 50% drug release immediately within few minutes followed by extended release. It was evident that the type and amount of solvents (mainly water and ethanol) were very important for wet granulation and film-coating of monolithic HPMC matrix tablet, because the plastic deforming and fragmenting properties of material were changed by the different strengths of the different solvents.

Acetaminophen↗

Absolute bioavailability of mianserin tablets and solution in healthy humans.

A pharmacokinetic study with mianserin . HCl was performed in six healthy male subjects. The subjects were treated on different occasions intravenously with a constant-rate infusion of 5 mg mianserin. HCl in 1 h, orally with a single dose of 60 mg as two tablets of 30 mg each and with 60 mg as an oral solution. The wash-out period between treatments was 1 month. Blood samples were taken at predetermined times over a period of 120 h following dosing. The mianserin concentration in the plasma samples was determined and the results were pharmacokinetically analyzed. The intravenous data could be adequately described by a 3-compartment model and the oral data by a 2-compartment model, both with first-order transfer and elimination rate constants. The mean plasma clearance of mianserin was found to be 19 +/- 2 l h-1 (mean +/- SEM), the kinetic volume of distribution 444 +/- 250 l, the steady-state volume of distribution 242 +/- 171 l and the elimination half-life 33 +/- 5 h. The absolute bioavailability in terms of extent of absorption was 22 +/- 3% for the solution and 20 +/- 3% for the tablets. The mean peak level for the solution was 79 +/- 11 ng X ml-1 and for the tablets 54 +/- 5 ng X ml-1; mean peak time for the solution was 1.1 +/- 0.2 h and for the tablets 1.4 +/- 0.2 h. The mean absorption half-life for the solution was 0.43 +/- 0.13 h and for the tablets 0.39 +/- 0.11 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Combined Fourier-transform infrared imaging and desorption electrospray-ionization linear ion-trap mass spectrometry for analysis of counterfeit antimalarial tablets.

This paper reports use of a combination of Fourier-transform infrared (FTIR) spectroscopic imaging and desorption electrospray ionization linear ion-trap mass spectrometry (DESI MS) for characterization of counterfeit pharmaceutical tablets. The counterfeit artesunate antimalarial tablets were analyzed by both techniques. The results obtained revealed the ability of FTIR imaging in non-destructive micro-attenuated total reflection (ATR) mode to detect the distribution of all components in the tablet, the identities of which were confirmed by DESI MS. Chemical images of the tablets were obtained with high spatial resolution. The FTIR spectroscopic imaging method affords inherent chemical specificity with rapid acquisition of data. DESI MS enables high-sensitivity detection of trace organic compounds. Combination of these two orthogonal surface-characterization methods has great potential for detection and analysis of counterfeit tablets in the open air and without sample preparation.

Antimalarials↗

Saliva-resistant coating of tablets prevents oral release of penicillin: plasma but not saliva equivalence.

OBJECTIVE: To investigate saliva and plasma concentrations of penicillin after the intake of a conventional phenoxymethylpenicillin (PcV) tablet and a tablet with saliva-resistant coating (PcVsr), both containing 1 g penicillin. METHODS: The study had an open randomized crossover design and involved 24 healthy subjects. Saliva and blood were sampled intermittently for 6 h after tablet intake. RESULTS: Within the first 10 min after tablet intake penicillin was detected in saliva in ten subjects taking PcV and in none taking PcVsr (P < 0.001). These initial saliva concentrations were short-lasting, but in some subjects 50 to 100 times higher than those following the peak concentration in plasma, i.e. at 40 min or more after swallowing. From 40 min and onwards the saliva concentrations of penicillin were very similar for the two formulations. The elimination of high initial saliva concentrations may diminish ecological disturbances of the mouth flora as well as removing the unpleasant taste of penicillin. The plasma concentrations of penicillin were similar for the two formulations throughout the 6-h sampling period and the mean ratio of the area under the plasma concentration-time curve was 99% for PcVsr in relation to PcV, the 90% confidence interval being 86-115%. The corresponding values for the maximum plasma concentration were 108% and 93 127%. The time to maximum concentration was 45 min for PcVsr and 41 min for PcV. Thus, with regard to standard criteria which are based on systemic (plasma) concentrations, the formulations were bioequivalent despite the substantial difference in initial local (saliva) concentrations. CONCLUSION: Saliva-resistant coating of tablets can prevent oral release of penicillin without affecting the plasma concentrations. From a clinical point of view both local and systemic equivalence should be established before bioequivalence is assumed.

Adult↗

Comparative multiple dose plasma kinetics of lycopene administered in tomato juice, tomato soup or lycopene tablets.

BACKGROUND: Lycopene is mainly provided in tomato and tomato products in Western diet. Among other factors the systemic availability of lycopene from natural sources is dependent on release from the cell matrix as achieved by food processing. AIMS OF THE STUDY: The purpose of this study was to compare plasma concentration responses of total lycopene and its major isomers to dosing of the carotenoid as tomato juice, tomato soup or tablets containing synthetic lycopene. METHODS: Intake of lycopene rich food products was restricted throughout this randomized, parallel group study, including 6 volunteers per group. Following a 14 day lycopene depletion phase subjects ingested 20 mg of lycopene daily for 8 days as tomato juice, soup prepared from tomato paste or lycopene tablets. Lycopene plasma concentrations were monitored throughout the depletion and dosing phases and for 22 days post-dosing and kinetics were evaluated using both empirical and compartmental modelling. RESULTS: Irrespective of the lycopene treatment all-E lycopene was the predominant lycopene isomer, whereas 5-Z lycopene was the most abundant Z isomer. Plasma concentration response of total and all-E lycopene to dosing of the carotenoid in tablets and tomato soup was comparable but exceeded that of intake in tomato juice. No differences were noted in dose normalized 5-Z lycopene concentrations between groups. The estimates of efficient half-life were approximately 5 and 9 days for all-E and 5-Z lycopene, respectively. CONCLUSIONS: The systemic availability of synthetic lycopene from a tablet formulation is comparable to that observed from processed tomatoes (soup from tomato paste) and superior to that from tomato juice. No differences were observed in disposition kinetics of natural and synthetic lycopene. The synthetic lycopene tablet formulation used in this investigation may be of value for future clinical investigations.

Adolescent↗

Evaluation of the microcrystallinity of a drug substance, indomethacin, in a pharmaceutical model tablet by chemometric FT-Raman spectroscopy.

PURPOSE: To establish a chemometric method for the precise evaluation of the microcrystallinity of indomethacin (IMC) in a pharmaceutical model tablet, based on FT-Raman spectroscopy. METHODS: Standard sample powders of homogeneous mixtures of amorphous and crystalline IMC were prepared in various proportions. A calibration model for the crystallinity of IMC was constructed by partial least-square (PLS) analysis based on the multiplicative scatter correction (MSC)+second-derivative transformed Raman spectra. A calibration model for the crystallinity of IMC in a model pharmaceutical product (IMC/mannitol=1:9 wt/wt) was also constructed using homogeneous standard sample powders of various degrees of crystallinity of IMC. RESULTS: This technique was validated to detect to 2% an amorphous or crystalline material in IMC contained in the model product (0.2% of the total mass of the tablet). Using this technique, not only pressure-induced amorphization but also the difference in microcrystallinity of IMC at the surface and interior of a model product tablet was elucidated after compaction of the tablet. CONCLUSIONS: The established technique is ideally suited for precise quantification of microanalysis of drug substances and drug products, particularly at the surface and interior of the tablet.

Anti-Inflammatory Agents, Non-Steroidal↗

More rapid relief of pain with isosorbide dinitrate oral spray than with sublingual tablets in elderly patients with angina pectoris.

To evaluate the possibility of improving clinical practice in the treatment of angina pectoris, the duration of relief of pain with isosorbide dinitrate (ISDN) oral spray and sublingual tablets were compared in elderly patients with chronic stable angina pectoris. Nine patients (mean age 67 years) were studied in a randomized crossover trial. The patients underwent bicycle ergometry, which resulted in typical chest pain associated with electrocardiographic ST-segment depression in all 9. The patients received ISDN oral spray or sublingual tablets immediately on termination of exercise. At least 6 hours later another ergometry test was performed and the patients were crossed over to the other drug. ISDN spray relieved pain in all patients at a mean duration of 61.6 +/- 24.4 seconds after administration, whereas the duration of relief of pain by ISDN sublingual tablets was 112.4 +/- 70 seconds. The difference was highly significant (p less than 0.0005). It is concluded that clinical practice of treatment of angina pectoris in the elderly can be improved by using ISDN oral spray rather than sublingual tablets. The spray is effective at twice the rapidity of the sublingual tablet.

Administration, Oral↗

Determination of film-coated tablet parameters by near-infrared spectroscopy.

Near-infrared (near-IR) spectroscopy was used in the determination of three parameters of theophylline tablets film-coated with ethylcellulose. Spectra of individual intact tablets were collected on two near-IR spectrometers: a grating-based spectrometer, and an acousto-optic tunable filter spectrometer. Calibrations were developed for the prediction of the time to 50% dissolution (t50%) of theophylline for tablets of varying coat thickness, for the determination of the thickness of the ethylcellulose coat applied, and for the prediction of the hardness of coated tablets. Principal component analysis was performed on the spectra prior to calibration development. The standard errors of calibration (SEC) and prediction (SEP) for determination of dissolution rates were 2.8 and 6.6 min, respectively. The SEC for the coating thickness calibration was 0.0002 inches, with an SEP of 0.00024 inches, and the SEC and SEP for the determination of tablet hardness were 0.54 and 0.62 kilopons, respectively.

Solubility↗

Early intervention in migraine with sumatriptan tablets 50 mg versus 100 mg: a pooled analysis of data from six clinical trials.

BACKGROUND: In clinical trials evaluating sumatriptan in the treatment of moderate or severe migraine pain, the 50- and 100-mg doses have been comparably effective and well tolerated. OBJECTIVE: To assess the dose-efficacy relationship of sumatriptan tablets given early for mild pain, data from 6 randomized, double-blind, placebo-controlled, early-intervention studies of sumatriptan tablets 50 mg and 100 mg (5 of which have been published) were pooled for analysis. These constitute all the studies conducted to date of sumatriptan tablets prospectively given early for mild pain. METHODS: The primary efficacy end point in all the studies was the proportion of patients reporting a pain-free result (ie, mild, moderate, or severe pain reduced to none) 2 hours postdose. Other efficacy end points included the proportion of patients who were migraine free (ie, no pain and no associated symptoms of nausea, vomiting, photophobia, or phonophobia) 2 hours postdose; the proportion reporting worsening of pain (ie, moderate or severe pain) 2 hours postdose; and the proportion with a sustained pain-free result (ie, pain free from 2-24 hours postdose with no use of a second dose of study medication or of rescue medication). Tolerability was assessed by evaluating the incidence of individual adverse events. The investigators assessed each adverse event's relationship to study medication. RESULTS: The number of patients in the intent-to-treat population was 2297 (771 sumatriptan 50 mg, 759 sumatriptan 100 mg, 767 placebo). Patients' mean age ranged from 39.4 to 39.8 years across groups, and most patients were female (90%-92%) and white (89%-90%). A pain-free result 2 hours post dose was reported by significantly more patients who took either dose of sumatriptan tablets compared with placebo and by significantly more patients who took the 100-mg dose compared with the 50-mg dose (50 mg, 49%; 100 mg, 58%; placebo, 24%; P < 0.001, both sumatriptan doses vs placebo, and 100 mg vs 50 mg). A similar pattern was observed for migraine-free results 2 hours postdose (50 mg, 42%; 100 mg, 47%; placebo, 20%; P < 0.05, both sumatriptan doses vs placebo, and 100 mg vs 50 mg), worsening of pain 2 hours postdose (50 mg, 26%; 100 mg, 21%; placebo, 46%; P < 0.05, both sumatriptan doses vs placebo, and 100 mg vs 50 mg), and sustained pain-free results from 2 through 24 hours postdose (50 mg, 30%; 100 mg, 35%; placebo, 12%; P < 0.05, both sumatriptan doses vs placebo, and 100 mg vs 50 mg). Both doses of sumatriptan were well tolerated, and no dose-related trends in the incidence of individual drug-related adverse events were observed. CONCLUSIONS: In this analysis of pooled data from 6 clinical trials, sumatriptan tablets 50 mg and 100 mg administered early in a migraine attack while the pain was mild were well tolerated and significantly more effective than placebo. The 100-mg dose of sumatriptan was significantly more effective than the 50-mg dose.

Adult↗

Tableting and stability evaluation of enteric-coated omeprazole pellets.

In this study, fluidized-bed manufactured enteric-coated omeprazole pellets were compressed into tablets. The stability of the pellets and those of compressed tablets were evaluated for remaining omeprazole and for degradation products under an accelerated stability protocol. The data were analyzed using the artificial neural network (ANN) and analysis of variance (ANOVA). It was found that enteric-coated omeprazole pellets could be compressed into quickly disintegrating tablets using microcrystalline cellulose granules as the pressure absorbing matrix. The ANN, using the multilayer perceptron model, predicted that there was a positive correlation between tablet crushing strength and microcrystalline cellulose concentration. Microcrystalline cellulose matrix showed a strong plastic deformation and all the pellets inside the tablet maintained their integrity with no significant change in their surface properties. Omeprazole degradation in acid medium was mainly dependent on microcrystalline cellulose concentration. A 90-day accelerated stability test in brown glass bottles with a desiccant showed that all prototype formulations would result in an acceptable stability profile for both remaining omeprazole, and also for the increase of impurity concentrations.

Drug Evaluation, Preclinical↗

Benefits of die-wall instrumentation for research and development in tabletting.

Instrumented presses used in tabletting research and development are normally equipped to measure punch force and displacement. Die-wall monitoring is rare, probably because instrumentation and calibration are quite difficult. The authors critically examine the tenets of radial pressure measurement in compression physics. The theoretical background concerning axial to radial stress transmission during the different phases of the compression cycle is presented. The literature reporting on the use of radial stress measurement to assess the self-lubricating properties of materials or the effect of lubricants is reviewed. Examples of interpretation of radial pressure cycles to define the basic material behaviour are given. The influence of particle size and shape as well as that of process and formulation variables on die-wall response are also discussed. Substantial inconsistencies can be seen in the literature with respect to the interpretation of experimental data, often because of the poor reliability of results and mostly because powders are essentially not solid, isotropic bodies. There is also a distinct lack of complementary tabletting parameters that would help understanding their comparative benefits. For this reason, original data on 13 model compounds are presented together with a classification of the materials encountered in pharmaceutical tabletting, based on selected parameters. In conclusion, none of the determined parameters, including those derived from radial pressure measurement, is able, alone, to predict the material behaviour under compression. Although die-wall instrumentation contributes little to the development of improved tablet formulations, it is valuable for characterising the mechanical properties of the materials. This is particularly advantageous given that the mechanical properties account for variations in tabletting performance to a much greater extent than the magnitude of the interparticulate attractions. Nevertheless, because of the peculiar nature of powders compared to solid, isotropic bodies, there is a need to develop new models for analysing their behaviour and to put more emphasis on examination of time-dependent deformation in the later stage of the compression cycle.

Chemistry, Pharmaceutical↗

Quantitative evaluation of polymer concentration profile during swelling of hydrophilic matrix tablets using 1H NMR and MRI methods.

Many pharmaceutical tablets are based on hydrophilic polymers, which, after exposure to water, form a gel layer around the tablet that limits the dissolution and diffusion of the drug and provides a mechanism for controlled drug release. Our aim was to determine the thickness of the swollen gel layer of matrix tablets and to develop a method for calculating the polymer concentration profile across the gel layer. MR imaging has been used to investigate the in situ swelling behaviour of cellulose ether matrix tablets and NMR spectroscopy experiments were performed on homogeneous hydrogels with known polymer concentration. The MRI results show that the thickest gel layer was observed for hydroxyethylcellulose tablets, followed by definitely thinner but almost equal gel layer for hydroxypropylcellulose and hydroxypropylmethylcellulose of both molecular weights. The water proton NMR relaxation parameters were combined with the MRI data to obtain a quantitative description of the swelling process on the basis of the concentrations and mobilities of water and polymer as functions of time and distance. The different concentration profiles observed after the same swelling time are the consequence of the different polymer characteristics. The procedure developed here could be used as a general method for calculating polymer concentration profiles on other similar polymeric systems.

Cellulose↗

The difficulty in the assessment of the compression behaviour of powder mixtures: Double layer tablets versus arithmetic additivity rule.

The weighted arithmetic mean from values of a feature derived from the individual components is often used to calculate the theoretically expected compression behaviour of powder mixtures if no interparticulate interactions between the components occur. Alternatively, simulated and experimental double layer tablets are presented. The suitability of the various methods to serve as a reference for the assessment of the compression behaviour of powder mixtures shall be compared. Narrow and similar sieve fractions of maltitol and metamizol were mixed in various ratios of true volumes. Constant total true volumes of the single substances, powder mixtures, and layered powders of the same composition were compressed on an eccentric tabletting machine to a constant maximum geometric mean punch force. In addition, the compression of double layer tablets was mathematically simulated from the dynamic relative density-force data of the pure materials. At a given momentary force, the relative density of a simulated double layered powder bed is given by the harmonic mean of the relative density values of the pure materials weighted by their true volume fractions. The results show that the total, the net, and the expansion work change indeed almost linearly with the true volume fraction of the components in the double layer tablets, with the consequence that the plasticity index (=net work/total workx100) proceeds non-linearly. The slope of the Heckel plot 'at pressure' and the apparent mean yield pressure obtained from these Heckel data are non-linearly related to the true volume fraction. If the weighted arithmetic mean is used to analyse the compression behaviour of the powder mixtures, results are obtained which are incompatible or even contradictory between interrelated features. On the other hand, the double layer model provides a consistent evaluation. A good agreement between the results of the experimental and the simulated double layer tablets is found.

Algorithms↗

Influence of scale-up on the abrasion of tablets in a pan coater.

The purpose of this study was to examine the influence of batch size during scale-up on the abrasion and edge splitting of flat faced lactose tablets. The weight loss of white tracer tablets in a batch of blue coated tablets was investigated in a laboratory scale pan coater and a pilot scale pan coater as a function of different pan speeds and mixing times. It was observed that increasing batch size resulted in a decreased weight loss due to less edge damaging. The higher number of tablet impacts at the pan wall in the laboratory scale compared to the pilot scale might be the reason for this phenomenon. The common assertion that an increase in batch size in scale-up leads to a higher abrasion or tablet damaging was not supported in the current study.

Chemistry, Pharmaceutical↗

Mechanistic analysis of drug release from tablets with membrane controlled drug delivery.

The objective of this study was to receive detailed information on the mechanism of drug release from polyvinyl acetate (PVAc)/polyvinyl alcohol-polyethylene glycol graft copolymer (PVA-PEG) coated Propranolol HCl and Theophylline tablets. For this purpose the coating composition (PVAc/PVA-PEG: 90/10 and 80/20) and the amount of the coating layer have been varied. Due to its better solubility Propranolol HCl showed higher release rates than Theophylline. As expected, a higher percentage of the water soluble polymer accelerated drug release. Increased coating thickness led to amplified lag times of drug release. The water uptake of the tablets was quantified by gravimetric analysis. Furthermore, the microenvironment of the tablet core was monitored by EPR spectroscopy. For this purpose a hydrophilic EPR spin probe was incorporated into tablets. Surprisingly, despite a lag phase at the beginning and a controlled drug release over 24 h, the results of the EPR studies indicated an immediate water penetration through the coating layer into the tablet core. The water is able to solubilise the majority of water soluble compounds within minutes. The results obtained in this study demonstrate, that EPR is a powerful method to monitor the first steps of diffusion processes and the physicochemical state of coated dosage forms.

Biopolymers↗

Development of a dissolution medium for nimodipine tablets based on bioavailability evaluation.

A marked difference in the dissolution rate between two brands of nimodipine tablets was observed using a newly developed dissolution medium of pH 4.5 acetate buffer containing 0.05% sodium dodecyl sulfate (SDS). However, when pH 4.5 acetate buffer containing 0.3% SDS was used as dissolution medium, which was specified in the edition, the dissolution results of the both brands conformed to the BP requirements and no significant difference in dissolution was observed. The dissolution data obtained for two commercial brands of nimodipine tablets indicate the superiority of the proposed system as a discriminatory dissolution medium for nimodipine tablets. The relative bioavailability of the two brands of nimodipine tablets was determined in healthy adult volunteers after a single dose in a randomized crossover study. Plasma concentrations were determined by a liquid chromatography-tandem mass spectrometry method. Statistical comparison of the AUC(0-T), AUC(0- infinity), C(max), and T(max) indicated a significant difference in the two brands of nimodipine tablets.

Adult↗

A new approach for preparing a controlled release ketoprofen tablets by using beeswax.

Solid lipid ketoprofen micropellets (SLKM) at different drug/beeswax ratios [(1:1) and (1:2)] were prepared by emulsion congealing technique and then compressed into tablets. Ketoprofen in solid state was incorporated into the melted beeswax at 90 degrees C and the mixture was emulsified in the hot aqueous Tween 80 solution by stirring at a constant rate. The SLKM were obtained by cooling the coarse emulsion down to room temperature and filtering. Drug entrapment efficiency and particle size analysis by laser diffractometry (LD) were determined, and existence of a drug-lipid interaction was investigated by differential scanning calorimetry (DSC) on the SLKM, before being compressed into the tablets by direct compression method. Finally, in vitro release studies were performed and the release kinetics of the waxy tablets were calculated. A commercial ketoprofen retard tablet (reference: Profenid Retard 200 mg) was also examined to compare the release properties. While the data obtained from DSC were indicating absence of drug-lipid interaction in the SLKM, it was determined that 28.62% (+/-2.08), 38.60% (+/-1.91) and 47.00% (+/-1.82) of ketoprofen was released from the tablets containing (1:2) and (1:1) SLKM and Profenid Retard 200 mg in pH 7.4 phosphate buffer solution after 8 h, respectively.

Anti-Inflammatory Agents, Non-Steroidal↗