Effects of Pigeon Pea and Plantain Starches on the Compressional,Mechanical, and Disintegration Properties of Paracetamol Tablets

ABSTRACT

A study has been made of the effects of pigeon pea starch obtained from the plant Cajanus cajan (L) Millisp. (family Fabaceae) and plantain starch obtained from the unripe fruit of Musa paradisiaca L. (family Musaceae) on the compressional, mechanical, and disintegration properties of paracetamol tablets in comparison with official corn starch BP. Analysis of compressional properties was done by using density measurements, and the Heckel and Kawakita equations, whereas the mechanical properties of the tablets were evaluated by using tensile strength (T-a measure of bond strength) and brittle fracture index (BFI-a measure of lamination tendency). The ranking for the mean yield pressure, P_y, for the formulations containing the different starches was generally corn < pigeon pea < plantain starch while the ranking for P_k, an inverse measure of the amount of plasticity, was pigeon pea < plantain < corn starch, which indicated that formulations containing corn starch generally exhibited the fastest onset of plastic deformation, whereas those formulations containing pigeon pea starch exhibited the highest amount of plastic deformation during tableting. The tensile strength of the tablets increased with increase in concentration of the starches while the Brittle Fracture Index decreased. The ranking for T was pigeon pea > plantain > corn starch while the ranking for BFI was corn > plantain > pigeon pea starch. The bonding capacity of the formulations was in general agreement with the tensile strength results. The disintegration time (DT) of the formulation increased with concentration of plantain and corn starches but decreased with concentration of pigeon pea starch. The general ranking of DT values was plantain < pigeon pea < corn starch. Notably, formulations containing pigeon pea starch exhibited the highest bond strength and lowest brittleness, suggesting the usefulness of pigeon pea starch in producing strong tablets with minimal lamination tendency. Plantain starch, on the other hand, would be more useful where faster disintegration of tablet is desired. The results show that the starches could be useful in various formulations depending on the intended use of the tablets with the implication that the experimental starches can be developed for commercial purposes.     

Water Uptake and Disintegrating Force Measurements: Towards a General Understanding of Disintegration Mechanisms

Water penetration and disintegrating force measurements were combined with the aim of assessing the role played by various mechanisms in the disintegration process.

Nine tablet series, made of differing base materials (α-lactose monohydrate, dicalcium phosphate dihydrate and acetylsalicylic acid) such as are likely to elicit differing disintegration mechanisms and containing differing disintegrates in varying percentages were prepared and checked for Water penetration, disintegrating force development and disintegration time.

The results obtained show that, in tablets made of dicalcium phosphate dihydrate or acetylsalicylic acid, a correlation exists between disintegration time and disintegrating force kinetics, which indicates that active mechanisms play the prevailing role in the disintegration process.

On the contrary, the lack of such a correlation in lactose monohydrate tablets indicates that passive mechanisms are also involved in the disintegration process and prevail over active mechanisms. In this case, water penetration rate, rather than disintegrating force development rate, seems to be the governing factor in the disintegration process.     

Effect of Pressure on Disintegration of Tablets and Dissolution of Ephedrine Sulfate

The influence of applied pressure on the disintegration of model ephedrine sulfate tablets and the release of ephedrine sulfate is reported. Six frequently used disintegrating agents were employed with a water-soluble diluent (lactose) and with a water-insoluble diluent (dibasic calcium phosphate). Although disintegration time may be independent of pressure (dibasic calcium phosphate) or may be lengthened by increased pressures (lactose), changes in applied pressures did not significantly alter the dissolution of the water-soluble medicinal compound.     

Effect of Pressure on Disintegration of Tablets and Dissolution of Ephedrine Sulfate

Abstract

The influence of applied pressure on the disintegration of model ephedrine sulfate tablets and the release of ephedrine sulfate is reported. Six frequently used disintegrating agents were employed with a water-soluble diluent (lactose) and with a water-insoluble diluent (dibasic calcium phosphate). Although disintegration time may be independent of pressure (dibasic calcium phosphate) or may be lengthened by increased pressures (lactose), changes in applied pressures did not significantly alter the dissolution of the water-soluble medicinal compound.     

A Comparative Evaluation of Some Starches as Disintegrants for Double Compressed Tablets

Abstract

The effect of different types and concentrations of some starches as disintegrants on the properties of aspirin tablets as a model for double compressed tablets was studied. The formulated tablets were evaluated using the U.S.P. official tests and some other selected nonofficial tests. These tests include: uniformity of weight, uniformity of content, disintegration, dissolution, hardness, friability and thickness. Maize starch was found to be the most suitable disintegrant for the formulation of double compressed tablets while rice starch was the worst disintegrant, in this study, as it significantly increased the hardness of tablets and showed a prolonged disintegration time as well as a poor dissolution rate. increasing the starch content of tablets resulted in a marked increase in their dissolution rate.     

A Comparative Evaluation of Some Starches as Disintegrants for Double Compressed Tablets

The effect of different types and concentrations of some starches as disintegrants on the properties of aspirin tablets as a model for double compressed tablets was studied. The formulated tablets were evaluated using the U.S.P. official tests and some other selected nonofficial tests. These tests include: uniformity of weight, uniformity of content, disintegration, dissolution, hardness, friability and thickness. Maize starch was found to be the most suitable disintegrant for the formulation of double compressed tablets while rice starch was the worst disintegrant, in this study, as it significantly increased the hardness of tablets and showed a prolonged disintegration time as well as a poor dissolution rate. increasing the starch content of tablets resulted in a marked increase in their dissolution rate.     

Ontrolled-Release Theophylline Tablet Formulations Containing Acrylic Resins. I. Dissolution Properties of Tablets

Abstract

The dissolution properties of controlled-release theophylline tablets containing acrylic resins are presented. Four different resins (Eudragit RSPM, RLPM, Sl00 and Ll00) were incorporated into theophylline tablets by direct compression techniques and the properties of the resulting dosage form were evaluated in dilute acid, buffer media pH 4.0 and simulated intestinal media pH 7.5. Tablets (500 mg) containing 300 mg of theophylline were prepared with each of the four resins and compressed to a hardness level of 6.5 to 7.5 kg. Excellent flow properties, weight uniformity and drug content uniformity were observed with all tablet formulations. Preliminary data suggest that three of the four resins tested showed great promise as a retardant in a matrix controlled drug delivery system. The dissolution properties of three commercially available sustained-release theophylline tablets were also determined. A comparison of profiles from Theodur^R (300 mg) in acid and simulated intestinal media showed a similarity in release properties to those of theophylline in tablets containing the RLPM resin.     

Ontrolled-Release Theophylline Tablet Formulations Containing Acrylic Resins. I. Dissolution Properties of Tablets

The dissolution properties of controlled-release theophylline tablets containing acrylic resins are presented. Four different resins (Eudragit RSPM, RLPM, Sl00 and Ll00) were incorporated into theophylline tablets by direct compression techniques and the properties of the resulting dosage form were evaluated in dilute acid, buffer media pH 4.0 and simulated intestinal media pH 7.5. Tablets (500 mg) containing 300 mg of theophylline were prepared with each of the four resins and compressed to a hardness level of 6.5 to 7.5 kg. Excellent flow properties, weight uniformity and drug content uniformity were observed with all tablet formulations. Preliminary data suggest that three of the four resins tested showed great promise as a retardant in a matrix controlled drug delivery system. The dissolution properties of three commercially available sustained-release theophylline tablets were also determined. A comparison of profiles from Theodur^R (300 mg) in acid and simulated intestinal media showed a similarity in release properties to those of theophylline in tablets containing the RLPM resin.     

In-Vivo Evaluation of a Bioadhesive Containing Indomethacin Tablets

The relative bioavailability of a bioadhesive containing, directly compressed, tablet formulation against the commercial indomethacin capsules “Indocid, MSD” has been investigated in dogs. The tablets showed a prolongation of the time to reach maximum concentration to 3 hours compared to 2 hours in capsules. They also showed 39% and 184% increase in maximum and minimum plasma concentration, respectively. The relative bioavailability of the tablets is 152% compared to capsules where the tablets showed a mean area under the plasma concentration-time curve of 26 ug.hr/ml compared to 17 ug.hr/ml for capsules.     

In-Vivo Evaluation of a Bioadhesive Containing Indomethacin Tablets

The relative bioavailability of a bioadhesive containing, directly compressed, tablet formulation against the commercial indomethacin capsules “Indocid, MSD” has been investigated in dogs. The tablets showed a prolongation of the time to reach maximum concentration to 3 hours compared to 2 hours in capsules. They also showed 39% and 184% increase in maximum and minimum plasma concentration, respectively. The relative bioavailability of the tablets is 152% compared to capsules where the tablets showed a mean area under the plasma concentration-time curve of 26 ug.hr/ml compared to 17 ug.hr/ml for capsules.     

Optimization of Slow-Release Tablet Formulations: Containing Montmorillonite I. Properties of Tablets

Slow-release tablets containing 20%. sodium sul fathiazole and 30%. magnesium aluminum silicate were prepared by direct compression techniques. Dissolution studies indicated that tablet hardness exerted a negligible influence on drug release from the tablets. During the dissolution process the clay slowly swelled to form a gelatinous hydrated layer around the tablet matrix. At faster stirring speeds, friction between the dissolution basket and the tablet rapidly removed the hydrated boundary region and resulted in a more rapid dissolution rate of the sulfonamide. Faster rates of dissolution were seen in deionized water than in dilute acid since the clay hydrated more readily at the higher pit.     

Effects of Temperature,Humidity, and Aging on the Disintegration and Dissolution of Acetaminophen Tablets

Abstract

The effect of storage for 8 weeks at 40°C in moderate and high humidity on acetaminophen tablets prepared by the wet granulation method using povidone or pregelatinized starch as a binder was studies. Storage at 52% relative humidity produced an increase in hardness of acetaminophen tablets and storage at 94% relative humidity caused a decrease in hardness. In all cases tablets granulated with pregelatinized starch were less susceptible to change caused by humidity than tablets granulated with povidone. The disintegration of tablets containing starch or povidone was slowed as the humidity was increased. Tablets stored at 40 =C and 94 V. relative humidity showed a substantial slowing of dissolution, but there was little change of dissolution of tablets when aged at 40 -C / 52% relative humidity. In comparing starch and povidone as binders, acetaminophen tablets prepared with pregelatinized starch were less effected by high humidity than tablets prepared with povidone.     

Dissolution Kinetics Evaluation of Controlled-Release Tablets Containing Propranolol Hydrochloride

In the present research, controlled-release propranolol hydrochloride tablets were prepared for twice-daily administration, allowing more uniform plasmatic levels of the drug. Pharmaceutical formulations were prepared with hydrophobic Eudragit® RSPO. The physical properties of the tablets were determined. Dissolution tests were performed in capsules containing the raw material using the following dissolution media: (A) distilled water, (B) simulated gastric juice without enzymes, and (C) simulated enteric juice without enzymes. A dissolution test was also performed for simulated samples (tablets) using distilled water as the dissolution medium.     

Effect of Aging on the Bioavailability of Nitrdfurantoin Tablets Containing Carbopol 934

Abstract

This article reports a study of two nitrofurantoin tablet formulations differing in the percentage of Carbopol 934 used as binder. The tablets of both formulations each contained 50 mg of nitrofurantoin. Those of formulation A contained 0.625 mg of Carbopol 934, and those of formulation B 1.25 mg. When freshly prepared, tablets of both formulations were bioequivalent to capsules containing 50 mg of nitrofurantoin, but a year's storage at 40°C and 60% relative humidity caused a significant decrease in the bioavailability of nitrofurantoin from formulation B, whereas formulation A was still bioequivalent to capsules. USP XXI Ed. Method II successfully reflected the observed variations in bioavailability, but not Method I.     

Effect of Aging on the Bioavailability of Nitrdfurantoin Tablets Containing Carbopol 934

This article reports a study of two nitrofurantoin tablet formulations differing in the percentage of Carbopol 934 used as binder. The tablets of both formulations each contained 50 mg of nitrofurantoin. Those of formulation A contained 0.625 mg of Carbopol 934, and those of formulation B 1.25 mg. When freshly prepared, tablets of both formulations were bioequivalent to capsules containing 50 mg of nitrofurantoin, but a year's storage at 40°C and 60% relative humidity caused a significant decrease in the bioavailability of nitrofurantoin from formulation B, whereas formulation A was still bioequivalent to capsules. USP XXI Ed. Method II successfully reflected the observed variations in bioavailability, but not Method I.     

Physicochemical Characterization and Evaluation of Buccal Adhesive Tablets Containing Omeprazole

The objective of this study was to develop an effective omeprazole buccal adhesive tablet with excellent bioadhesive force and good drug stability in human saliva. The omeprazole buccal adhesive tablets were prepared with various bioadhesive polymers, alkali materials, and croscarmellose sodium. Their physicochemical properties, such as bioadhesive force and drug stability in human saliva, were investigated. The release and bioavailability of omeprazole delivered by the buccal adhesive tablets were studied. As bioadhesive additives for the omeprazole tablet, a mixture of sodium alginate and hydroxypropylmethylcellulose (HPMC) was selected. The omeprazole tablets prepared with bioadhesive polymers alone had bioadhesive forces suitable for a buccal adhesive tablet, but the stability of omeprazole in human saliva was not satisfactory. Among alkali materials, only magnesium oxide could be an alkali stabilizer for omeprazole buccal adhesive tablets due to its strong waterproofing effect. Croscarmellose sodium enhanced the release of omeprazole from the tablets; however, it decreased the bioadhesive forces and stability of omeprazole tablets in human saliva. The tablet composed of omeprazole/sodium alginate/HPMC/magnesium oxide/croscarmellose sodium (20/24/6/50/10 mg) could be attached on the human cheek without disintegration, and it enhanced the stability of omeprazole in human saliva for at least 4 h and gave fast release of omeprazole. The plasma concentration of omeprazole in hamsters increased to a maximum of 370 ng/ml at 45 min after buccal administration and continuously maintained a high level of 146-366 ng/ml until 6 h. The buccal bioavailability of omeprazole in hamsters was 13.7% ± 3.2%. These results demonstrate that the omeprazole buccal adhesive tablet would be useful for delivery of an omeprazole that degrades very rapidly in acidic aqueous medium and undergoes hepatic first-pass metabolism after oral administration.     

Moisture, Hardness, Disintegration and Dissolution Interrelationships in Compressed Tablets Prepared by the Wet Granulation Process

Interrelationships among moisture, hardness, disintegration and dissolution in compressed tablets were studied by compressing tablets from granulations prepared by the wet granulation process containing low moisture levels. Hardness, disintegration and dissolution of these tablets did not change on exposure to ambient room conditions. After equilibration under high humidities, a decrease in tablet hardness occurred which depended linearly on tablet hardnesses at the time of compression. After overnight exposure to ambient room conditions, the softened tablets increased in hardness and this increase greatly exceeded the initial hardnesses. The magnitude of hardness increase was independent of the hardnesses at the time of compression. Increased tablet hardnesses resulted in an increase in the disintegration time, although in vitro dissolution of the drug remained unaffected. The results suggest that moisture gain and subsequent loss on storage under varying humidity conditions could account for major increases in hardness of compressed tablets in storage.     

Physicochemical Characterization and Evaluation of Buccal Adhesive Tablets Containing Omeprazole

The objective of this study was to develop an effective omeprazole buccal adhesive tablet with excellent bioadhesive force and good drug stability in human saliva. The omeprazole buccal adhesive tablets were prepared with various bioadhesive polymers, alkali materials, and croscarmellose sodium. Their physicochemical properties, such as bioadhesive force and drug stability in human saliva, were investigated. The release and bioavailability of omeprazole delivered by the buccal adhesive tablets were studied. As bioadhesive additives for the omeprazole tablet, a mixture of sodium alginate and hydroxypropylmethylcellulose (HPMC) was selected. The omeprazole tablets prepared with bioadhesive polymers alone had bioadhesive forces suitable for a buccal adhesive tablet, but the stability of omeprazole in human saliva was not satisfactory. Among alkali materials, only magnesium oxide could be an alkali stabilizer for omeprazole buccal adhesive tablets due to its strong waterproofing effect. Croscarmellose sodium enhanced the release of omeprazole from the tablets; however, it decreased the bioadhesive forces and stability of omeprazole tablets in human saliva. The tablet composed of omeprazole/sodium alginate/HPMC/magnesium oxide/croscarmellose sodium (20/24/6/50/10 mg) could be attached on the human cheek without disintegration, and it enhanced the stability of omeprazole in human saliva for at least 4 h and gave fast release of omeprazole. The plasma concentration of omeprazole in hamsters increased to a maximum of 370 ng/ml at 45 min after buccal administration and continuously maintained a high level of 146–366 ng/ml until 6 h. The buccal bioavailability of omeprazole in hamsters was 13.7% ± 3.2%. These results demonstrate that the omeprazole buccal adhesive tablet would be useful for delivery of an omeprazole that degrades very rapidly in acidic aqueous medium and undergoes hepatic first-pass metabolism after oral administration.     

Effects of Binders and Moisture Content on the Disintegration,Hardness and Friability of Paracetamol and Orphenadrine Citrate Tablets

Abstract

The effects of binders and moisture content on the disintegration time, friability and hardness of paracetamol and orphenadrine citrate tablets at different storage conditions were investigated. These parameters were determined after one, four and sixteen weeks of storage

The use of starch, ethocel or CMC Na as binders gave unsatisfactory tablets because of their high friability. Unacceptably high disintegration times were obtained, particularly at higher storage temperatures when PVP was used. Capping and yellow spotting observed in gelatin formulations makes this binder unsuitable for use. Methocel granulations yielded satisfactory tablets with acceptable disintegration time, hardness and friability and were unaffected by storage at different conditions of temperature and humidity