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CHAPTER 2

REVIEW

OF

LITERATURE

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Re view of Lite rature

CHAPTER 2

2. 1

2.2

2.3

2.4

2.5

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Review of Literature

2.1 DIRECTLY COMPRESSmLEADJUVANTS

Armstrong [I] examined the issue of less frequent use of direct

compression as compared to wet granulation for tablet production. He

suggested guidelines for selection of diluents. He reported that flow,

consolidation, aggregation under pressure and ejection are vital properties

that affect the selection of diluents for direct compression. Direct

compression requires more stringent demands on particle properties like

particle sbape, size, flowability, etc.

Jivraj et al. [2] reviewed various useful direct compressible diluents. They

stated that the bumble tablet dosage fonn still accounts for more than

80% of all dosage forms administered to man. The review outlined the

various excipients that have been used as fillers in direct compression

formulations, with particular emphasis on what is expected from such

excipients in terms of their functionality. They intended that the overview

(which is by no means exhaustive) will serve as an 'aidememoire' to the

fonnulation scientists.

Voort and Bolhuis [3] reported in their articles that the ability of a

powder to compact into tablets is dependent on a balance between the

plastic deformation and brittle fracture properties of the powder particles.

For proper bonding forces, plasticity is necessary to sufficiently reduce

the distance between adjacent particles. A brittle fracture is required to

reduce sensitivity towards lubricants. As this balance is not perfect in

virtually most of all materials, modem directly compressible materials are

treated and are made up agglomerates of fine particles produced by

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Review of Literature

granulation, spray drying or co-processing. Some of these fine particles

are plastic and agglomerate formation introduces brittleness, making

tablets both strong and insensitive to lubricants.

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Review of Literature

2.2 DIRECTLY COMPRESSmLE CELLUWSE

Reimerdes [4] surveyed the range of options open to optimize excipient

performance in co-processing of excipients or drugs and excipients. The

various co-processed excipients such as LudipressR, CellactoseR

, Di-PacR

and MannitabR were studied. The co-processed material of lactose and

cellulose, which is known as Cellactose", was found to have excellent

tableting characteristics. Co-processing is an interesting method because

the products are physically modified in a special way without losing their

chemical structure and stability. The rheological properties of lactose

were improved by co-processing it with Eudragit.

Diltgen et al. [5] examined the powder and tableting properties of

different brands of microcrystalline cellulose and correlated the tableting

properties with the crystallinity of the cell uloses. The study helped them

to choose a material for direct tableting.

Armstrong et al. [6] studied the mechanism of consolidation of diluents

and concluded that an ideal diluent should compose of fragmenting and

deforming components to obtain the advantages of both mechanisms.

They studied the properties of a new commercially available directly

compressible diluent-CellactoseR It is a co-processed one-body

compound of granular shape consisting of three-quarters lactose and one

quarter cellulose. It cont$s a fragmenting component (lactose) and a

substance that consolidates primarily by deformation (cellulose). They

studied the relationship between applied pressure and tablet tensile

strength for mixtures of CellactoseR and ascorbic acid. They concluded

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Review of Literature

that CellactoseR gives more porous tablets at the studied pressures with

greater strength.

Jeffrey and Reigate [7] developed silicified microcrystalline cellulose to

circumvent the problem of loss of compressibility of microcrystalline

cellulose during wet granulation which leads to an increased need of

binders. Silicification of microcrystalline cellulose resulted in enhanced

flow and compactibility compared to untreated microcrystal line cellulose

in direct compression and wet granulation. This also leads to

improvement in drug content uniformity, reduction in tablet size and the

ability to utilize poorly compressible drugs without need for granulation.

Vijay Kumar et al . [8] evaluated the tableting characteri stics of low

crystallinity celluloses (LCPC-700, LCPC-2000 and LCPC-4000) and

compared their performance with those of Avicel PH- 102 and Avicel PH-

302. Low crystall.inity cellulose (LCPC) is a direct compression excipient

prepared by reacting cellulose with 85% w/w phosphoric acid. They

concluded that LCPC-4000 was the most ductile material and exJ'ibited

the highest compression and compaction characteristics. The

corresponding properties of LCPC-700 and LCPC-2000 were comparable

to that of Avicel PH-I02 or Avicel PH-302.

Ming-Thau S. and coworkers [9] evaluated the effect of manufacturing

factors on the material properties and functionality of microcrystalline

cellulose. The results demonstrated that the desired material properties

and functionality of microcrystalline cellulose can be obtained by

manipulation of the manufacturing factors using proper polynomial

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Review of Literature

equations. The key factor was identified as temperature of manufacturing.

They reported that the functionality could be quantitatively predicted by

material properties. The key material property was identified as molecular

mass in controlling microcrystalline cellulose functionality. They

concluded that the careful control of temperature during the manufacture

of microcrystalline cellulose might minimize inter-batch variation. The

correlation of the material properties of microcrystalline cellulose

products with their functionalities might help the formulation designer to

rationally select proper microcrystalline cellulose products. The universal

harmonization of microcrystalline cellulose products might be achi eved

by the regulation of their molecular mass, surface roughness, and

roundness.

Nadaa and Oraf [10] developed Vitacel M80K, a cellulose powder coated

with 2% colloidal silica, as direct compressible vehicle (DCV). They

investigated the performance of Vitaeel M80K, in comparison with a .

laboratory prepared vehicle (ELC+) consisting of a mixture of Elcema

POSO (ELC) and 2% Aerosil, microcrystalline cellulose (MCC) and

Avicel PH 101. Bulk density, flow and surface characteristics of the

direct compressible vehicles were determined. Tablets were prepared by

direct compression using various drugs: ascorbic acid (fine and coarse

crystals), cirnetidine, and paracetarno!. Tablets prepared with Vitacel

M80K showed less weight variation than those prepared with Avice!.

Ascorbic acid-Avicel tablets were slightly harder than those with Vitacel

M80K. However, in the presence of either cirnetidine or paracetamol,

M80K resulted in the production of tablets with maximum hardness. In

most cases, except with paracetarnol, Vitacel M80K produced tablets

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Review of Literature

with slightly higher friability in comparison to A vicel, while ELC+

showed maximum friability. Vitacel M80K-paracetamol tablets showed

the minimum friability values and highest hardness sensitivity towards

increase of the applied compression force between 5 and 35 kN. Vitacel

M80K-containing formulations showed better hardness tolerance upon

the addition of magnesium stearate. Disintegration times for most tablets

were relatively short « 5 min).

The effect of compressional force on the crystallinity of low crystallinity

cellulose (LCPC), microcrystalline celluloses (AvicelR PH-IO I, PH-I02

and PH-302 grades) and powdered cellulose (Solka Floc BW-lOO) was

been investigated by Vijay Kumar and Kothari [II]. Microcrystall ine and

powdered cell uloses showed an increase of about 10% in their

crystallinity, compared to the values for the corresponding powders, at a

compression pressure of 5- 10 MPa. The increase in the crystallinity of

LCPC was gradual and reached the maximum value of 5% at a

compression pressure of 15 IvfPa. Further increase in compression

pressure to 77 MPa had no effect on the crystallinity of LCPC, Avicel"

PH-tol, AvicelR PH-302 and Solka Floc BW-toO. AvicelR PH-I02, on

the other hand, showed a decrease in crystallinity at 15 MPa. Beyond 15

MPa, however, no statistically significant change in the crystallinity of

the product was noted.

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Review of Literature

2.3 DIRECTLY COMPRESSffiLE LACTOSE d( Lf -<- L1

Hwang and Peck [12] used lactose, starch, microcrystalline cellulose and

dicalcium phosphate as tablet and capsule fillers. They studied the effects

of the lubricant level, lubrication time and the compression speed for the

fillers. The crushing strength of lactose tablets was sensitive to the

lubricant level and compression speed, but the flowability was sufficient

to accommodate the increase in compression speed . For dicalcium

phosphate, higher lubricant levels decreased flowability and

compactibility, but increased lubricity.

Fell and Newton [13] studied the compaction properties of spray-dried

and crystalline lactose. The tensile strength of tablets prepared using the

two forms of lactose was compared by means of compression test. The

results illustrated a linear relation between tensile strength and

compaction force for the samples under the test conditions. The tensile

strength of the compacts increased with a decrease in particle size. The

results illustrated difference in the tensile strength of compacted

crystalline and spray-dried lactose, which could be related to the various

tableting characteristics of the two forms oflactose.

Lerk and coworkers [14] transformed a-lactose monohydrate into

products with decreasing water content to modify lactose to an excipient

with high flowability, good compactibility and stability. Dehydration was

performed by thermal treatment and by desiccation with methanol. The

desiccation with methanol gave a much steeper increase in crushing

strength. However, thelmally dehydrated samples showed strong increase

in binding property with a decrease in water content. Scanning electron

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Review of Literature

microgJaphs illustIated the change of single particles into aggregates of

anhydrous lactose. The researcbers concluded that the thellnal

dehydration or desiccation by means of organic solvent like methanol can

convert crystals of alpha lactose monohydrate into a stable anhydrous

product with much increased binding capacity and excellent f1owability.

Wong et al. [IS] assessed the compression characteristics of single crystal

of a-lactose monohydrous and a - lactose anhydrous in two ways: a) by

indentation testing and b) by the use of novel single crystal compression .

They observed that the a -lactose monohydrous crystals were hard, elastic

and strong. Compression caused breaking off of both small and large

fragments from the crystals. The anhydrous form was found to be so ft,

less elastic and weaker.

Gunsel and Lachman [16] prepared tablet formulations using spray dried

lactose and conventional lactose in their study. The granule were

compared for particle size distribution, flow properties and moisture

content. The tablets were evaluated for hardness, friability, disintegration

time, weight content and color development at room temperature, 40°,

50° and 60° C for 12 hr. They concluded that the tablets made from spray

dried lactose exhibited better pbysical qualities in terms of crushing

strength, friability and disintegration time, but they were found to be

more susceptible to color development following storage at elevated

temperatures.

Batuyois [17] used directly compressible grade of anhydrous lactose as a

diluent in his investigation. It showed faster dissolution rate because no

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Review of Literature

colloidal binders (e.g. starch and gelatin) were used in granulations. The

results indicated good tablet content unifonnity and little weight variation

during the three-day compression period during which 5,00,000 tablets

were made at various speeds (upto 3500 tablets per min). The appearance,

hardness and friability of the tablets were reported to be excellent. High

temperature, high humidity and direct sunlight did not affect the tablets

chemically or physically.

Mishra and Rao [18] studied the modifications of lactose to provide

cheaper indigenous directly compressible lactose by thermal treatment of

lactose. The thermally modified lactose was prepared by drying

supersaturated aqueous solution of lactose in a paraffin bath . The

thermally modified lactose was evaluated and compared with

commercially available directly compressible lactose. The results

indicated that the flow properties of thennally modified lactose were

ranked below those of directly compressible lactose, but were better than

the parent material.

Mishra and Rao [19] prepared modified lactose by spray drying oflactose

slurry containing guar gum. The product consisted of agglomerates of

alpha lactose monohydrate held together by amorphous lactose and guar

gum. It was found to have better flow properties as well as compression

characteristics as compared to commercially available directly

compressible lactose.

•

Gohel and coworkers [20] prepared lactose based directly compressible

diluents by controlled freezing and thawing of solution of lactose. The

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Review of Literature

concentration of lactose and controlled nucleation were found to be the

most important parameters. In another method, the saturated solution of

lactose was used for preparation of free flowing agglomerates of lactose

particles. The volume of saturated lactose solution was found to be one of

the most significant formulation parameters in the second method. The

samples were compared with commercially available products and the

results revealed that the developed products met the required qualities of

directly compressible diluents.

Gohel and coworkers [Zl] prepared lactose and talc based directly

compressible diluents using controlled freezing and thawing metbods.

The amount of talc (IO-ZO% w/w of lactose) and the effect of stining rate

(ZOO-1500 rpm) were found to be the most important parameters. The

volume of binder (HPMC) solution (4-6 ml per IZ5 g solids) was found

to be the most significant parameter in mini granulation method.

Gohel and coworkers [ZZ] prepared co-processed diluents containing

lactose and microcrystalline cellulose. The ratio of lactose to

microcrystalline cellulose (75:Z5 or 85:15), the type of binder

(hydroxypropyl methylcellulose or dextrin) and binder concentration ( I

or 1.5%) were investigated as independent variables in a Z' factorial

design. The results of multipJe regression analysis and factorial analysis

of variance suggested that the flow rate was influenced by two-way

interactions than by the main. effects. The physical characterization using

bulk and tapped density, angle of repose, Carr's index, Hausner ratio and

flow rate showed that the agglomerates were suitable for direct

compression. Diltiazem HCl was used as a model drug to ascertain the

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Review of Literature

tableting characteristics of the products. Dextrin was found to be a better

binder than hydroxypropyl methyl cellulose.

Gohel et aI. [23] prepared agglomerated lactose for direct compression by

adopting a freeze-thaw method. Three adjuvants (polyethylene glycol

6000, polyvinylpyrrolidone or gelatin) were tried at four different

concentrations (0.5, I, 1.5, or 2% w/w of lactose). The products were

evaluated for particle size distribution, Carr's index, Hausner ratio, angle

of repose, granular friability index and moisture sensitivity. The

agglomerates prepared using polyethylene glycol 6000 showed superior

flow rate compared to that obtained using polyvinylpyrrolidone or gelatin

due to improved sphericity. The agglomerated lactose possessed direct

compressional qualities.

Juppo and coworkers [24] studied the effect of granulating liquid,

compression speed and maximum force on the compressibility and

compactibility of lactose, glucose and mannitol granules. The porosity

was based on the geomebical shape. The granules oflactose and mannitol

exhibited a greater compressibility than that of glucose containing

granules. Granules containing mannitol produced the hardest tablets,

while those of glucose and lactose produced the weakest. The change in

the amount of granulating liquid caused change in the porosity of

granules. All the parameters studied were relatively insensitive to change

in the speed of compression in the range used, except for the breaking •

force of mannitol tablets, which was greatest with the lowest speed of

compression. The tablets compressed from lactose granules had the best

weight and content uniformity.

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Review of Literature

Baykarn and Duman [25] studied a new directly compressible excipient,

LudipressR, which is a co-processed product, consisting of 93.4% (t­

lactose monohydrate (filler), 3.2% Kollidon 30 (binder), and 3.4%

Kollidon CL (disintegrant). The product consisted of a large number of

crystals with smooth surfaces. The binding properties of LudipressR, both

unlubricated and lubricated with I % magnesium stearate was found to be

much better than those of the physical mixture. After milling, LudipressR

can be recompressed with minor loss of binding properties. The dilution

potential of LudipressR, with respect to paracetamol, was found to be

lower than that of Avicel PH 10 I.

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Review of Literature

2.4 DIRECTLY COMPRESSmLE STARCH

Monedero and coworkers [26] studied consolidation mechanism of

Sepistab St 200", a directly compressible starch, in relation with Sta Rx

1500". The flowability of Sta Rx 1500R was high as compared to Sepistab

St 200"' No difference was observed in the consolidation mechanism of

the two on the basis of tablet-in-die Heckle method. The tablets

containing Sepistab St 200" showed immediate disintegration due to high

content of amylase.

Bolhuis et al. [27] evaluated modified rice starch as a direct compression

excipient using oxazepam as a model drug. Modified rice starch proved

to be a useful direct compression adjuvant. It can be used as a unique

filler-binder or in combination lactose. Combination of modified rice

starch with microcrystalline cellulose should be avoided because of the

poor flowability of the blends and slow disintegration of the tablets.

Thau- ming C. and coworkers [28] evaluated Era-Tab", a commercially

available modified starch and compared with commercially available

directly compressible excipients namely microcrystalline cellulose,

partially pregelatinized starch, Super tab LacR and Emcompress"' They

found that Era-Tab" possessed high flowability and adequate

compressibility. The tablets of Era-TabR showed higher crushing strength

and lower friability than that of other excipients. They concluded that

Era-TabR is a better direct compression tablet excipient.

•

Manudhane and Contractor [29] investigated tableting properties of a

directly compressible starch, which has many advantages over starch USP

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Review of Literature

with respect to fluidity and compressibility. The directly compressible

starch shows comparable results in terms of disintegration time and

dissolution rate to USP starch. Its high moisture content did not affect the

stability of aspirin when compressed as tablets. Amylose is shown to be

the effective component of starch for its disintegrant effect.

Leitritz and coworkers [30] studied force time curves of a rotary tablet

press and segmented it into three phases: the compression phase, the

dwell phase and the decompression phase. The following parameters

were investigated: the compression area, the compression slope

describing the initial phase, the area ratio and the peak offset time

characterizing the dwell time, the decompression area and the

decompression slope and total area under force-time curve. The area

ratio, peak offset time, dwell time and compression area are used for

phase-specification allocation of the occurrence of plastic flow, which is

found to be a function of compression force and moisture content. Tablet

strength, tablet porosity and in-die bulk porosity provide additional

information that porosity above the certain limit was found to be a

prerequisite for plastic flow within the compact. When the porosity limit

is reached, further densification remains elastic and leads to a reduced

compact strength during expansion. The area ratio, as a robust in-process

control parameter for plastically flowing formulations, is suggested as a

means of preventing this effect.

Karr et al. [31] studied the .comparison of starch NF and pregelatinized

starch NF incorporated in the granules containing a poorly water soluble

drug. Binding efficiency was directly proportional to the granule

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Review of Literature

coarseness, which, in tum, was directly proportional to mean work of

compression for equally well-lubricated granulation. The order of wet

binding efficiency was pregelatinised starch 1551 (dry» Sta Rx 1500

(dry» pre-gelatinized starch slurry> Sta Rx 1500 slurry> starch NF. The

formulations containing the modified starches exhibited a faster release of

low water soluble drug than those with starch N F.

Bolhuis et al. [32] evaluated compression characteristics of modified rice

starch (PrimotabR) , a new excipient for the preparation of tablets by direct

compression. It is an agglomerated rice starch having excellent fl ow and

disintegration. Compression characteristics were sufficient even after

mixing with a lubricant. The tablets containing oxazepam as a model drug

showed that the modified rice starch is a useful product for the

preparation of tablets by direct compression. They concluded that the

combinations of starch with microcrystalline cellulose should be avoided

because of the poor flowability of the blend and slow disintegration of tile

tablets.

Patel N. K. and coworkers [33] studied the stabili ty of a model

hydrolysable drug in combination with excipients having either hydrate

water (dibasic calcium phosphate dihydrate and lactose) or variable

adsorbed moisture depending upon environmental conditions

(microcrystalline cellulose and pregelatinized starch). Tablets containing

10% and 50% aspirin with these excipients were stored in open and •

closed bottles at various temperature and humidity. Pregelatinized starch •

based tablets were stable in closed containers for 30 weeks.

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Review of Literature

2.5 COLWIDAL SILICON DIOXIDE

Augsburger and Shangraw [34] studied effect of various silica-based

glidant in the direct compression of microcrystalline cellulose and spray­

dried lactose. All silica based glidants were found to improve the flow

property of microcrystalline cellulose as reflected in increased tablet

weights and decreased weight variation, where as spray-dried lactose

containing blend revealed reverse results. Pyrogenic silica and a silico­

aluminate were found to be the most effective glidant in terms of overall

performance.

Stephen and coworkers [35] evaluated the mechanical properties of

compacts of microcrystalline cellulose and silicified microcrystalline

cellulose. The results reported that the compacts of silici fied

microcrystalline cellulose exhibited greater strength than those of

microcrystalline cellulose. The compacts of silicified microcrystalline

cellulose exhibited greater stifthess and required considerably more

energy for tensile failure to occur. The mechanical data together with the

comparable densification characteristics of microcrystalline cellulose and

silicified microcrystalline cellulose suggested that the apparent strength

enhancement might be a consequence of an interfacial interaction rather

than modification of microcrystalline cellulose properties. These data

were in agreement for data reported for lubricated silicified

microcrystalline cellulose and microcrystalline cellulose tablets in that

silicification of microcrystalline cellulose appears to produce material

with greater binding capability. Comparison of the data with 'that obtained

for a dry blend of silicon dioxide and microcrystalline cellulose suggested

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Review of Literature

that the functionality benefits of silicification were not due to a simple

composite material model.

Varthalis and Pilpel [36] investigated the effect of colloidal silicon

dioxide (Cab-O-Sil M-S) on flow properties of single or mixed powders

of acetaminophen, lactose and oxytetracycline dihydrate. The

measurements of particle size and tensile strength showed that colloidal

silicoue dioxide acts as a glidant for acetaminophen and lactose, but as an

antiglidant for oxytetracycline dihydrate.

Lerk et al. [37] investigated the interaction of lubricants and colloidal

silica during mixing with ST A-Rx-ISOOR and its effect on tableting. The

effect of mixing time and mixing sequence on the crushing strength of

tablets compressed from blends of Sta-Rx-ISOOR with 0.5% magnesium

stearate and 0.2% colloidal silica and STA-Rx-1 S00R with 0.5% of

different lubricants was studied. They found that all the lubricants

decreased the crushing strength of the tablets with an increase in mixing

time of the blends. The greatest decrease in strength was observed when

magnesium stearate was included. The addition of colloidal silica to

magnesium stearate suppressed the deteriorating effect of magnesium

stearate on the crushing strength of the tablets.

Ragnarsson et al. [38] investigated the effect of mixing time and amount

of colloidal silica (Aerosil 200) on the lubricating properties of

magnesium stearate using· an instrumented single punch machine. ShOlt

mixing time decreased the negative effects of magnesium stearate on

tablet strength and disintegration without reducing the lubricating

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i?euie w 0 Literohlre -

l,tTictenC\ \ ddltlOIl of AC'lUsil 100 had 11 posi tive ctTcct on the strength

(If lubnct11l'Ci SNhll111 chl oride lahk ts, but increased the fri ction and did

11,')1 IInp"-" \,' 111(' dlsintt"p.mt1011 .

\ '"n .\erdc <t 31. [.19] described the compression behavior of paracet3111ol

and the Influence of the adjuvants like magnesiulll stearate. co llo idal

SIlicon dioxide and g1ycel)'1 behenate on the mechanical strength of the

tablets. The drug showed plastic deformation during compression. Silicon

dIoxide increased the tensile strength of dIe tablets. while the other two

adlU\'ants decreased the mechanical strength of the tablets. . -Moura et a1 . [40] ITIyestigated the influence of temperatme and the role of

collOIdal sihcon dioxide (Aerosil 200) on ascorbic acid stability during

the spray drying process. Temperature variation in the spray drying

method had no effect on the ascorbic acid degradation. Colloidal sil icon

dioxide unproved the final yield of spray drying in proportion to its

concentratIOn Drug release. from the spray-dried ascorbic acid was found

to be dependen1 on the si licon content.

LennarD and MIele!. 14 I J sturued the compactibili ty of powder mixtures

of accrarnmophen and Pharnlatose DeL 11 R in presence of magnesium

stearale and Aerosil 200. The results indicated that the mechanical

strength of small sued tablets of acetaminophen was eq ual to, and at high

pressures greater W3Il. mat of nonnal-sized tablets. The authors

concluded that the capping tendency of small sized tablets was reduced at

hIgher pressures

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Review of Literature

Palma et al. [42] developed a method to load fumed silicon dioxide (Cab­

O-Sil) with dried liquid extract of Melissa officinal is, Cardus marian us,

and Peumus boldus to obtain a product with satisfactory flow properties

and compressibility. Flowability, densities, and compactibility of directly

compressible lactose, calcium phosphate dibasic dihydrate

(EmcompressR), and microcrystalline cellulose (Avicel PH_lOI R

) were

not adversely affected when mixed with tlle loaded silica product.

Sindel and coworkers [43] investigated the influence mixing time on the

homogeneity of a powder mixture of lactose monohydrate and Cab-O-Sil

M5 . Optimum homogeneity in the powder mixture of lactose

monohydrate and colloidal silicon dioxide was observed after 3 min of

mixing. The mixing time up to 6 min had no statisti cally sign ificant

negative effect on the homogeneity o f the mi xture. However, after 8 min

of mixing, the sign of segregatiou in the mixture was observed. They

concluded that the angle of repose was very sensitive to changes in the

fJowability of the powder mixture.

Stubberud and Forbes [44] investigated the effect of a hygroscopic

excipient polyvinylpyrrolidone and two non-hygroscopic excipients,

crystalline a-lactose monohydrate (Pharmatose 350MR) and coll oidal

silicon dioxide (Cab-O-SiIR), on the recrystallization of amorphous

lactose at 55% and 75% relative humidity and 25°C. They concluded that

polyvinylpyrrolidone delayed the apparent onset of recrystallization of

amorphous lactose, while a-lactose monohydrate and colloidal silicon

dioxide significantly reduced the time for recrystallization of amorphous

lactose.

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Review of Literature

1.6 REFERENCES

I. Armstrong N. A , Manuf. Chem., 1986, 57,29.

2. Jivraj M., Martini L. G . and Thomson C. M., Phann Sci. Tech.

Today, 2000, 3(2), 58.

3. Yoort K. M. and Bolhuis G . K. , Phann. Tech. Eur., 1998, 10(9), 30

and 10(10), 28.

4. Reimerdes D., Manuf. Chem., 1993, 64, 14.

5 Dittgen M., Fricke S. and Gerecke H., Manuf. Chern ., 1993, 64, 17.

6. Annstrong N. A , Gabriele R. and Mohammed R.A K., Manuf.

Chem., 1996, 67, 25 .

7. Jeffrey D. A and Reigate, Manuf. CheJII ., 1996,67, 19.

8. Yijay Kumar, Sanjeev H. K. and Banker G. S., AAPS

PhannSciTech., 2001 , 2 (2), article 7. (http://www. phann

scitech.com)

9. Ming-Thau S., Jen-Sen W. and Hsiu H., Eur. J . Pharm. Sci., 200 1,

12, 41 7.

10. Nadaa A H . and Graf E., Eur. J. Phann. Biophann ., 1998, 46,347.

11. Yijay Kumar and Kothari S. H ., Int. J. Phann ., 1999, 177, 173 .

12. Hwang R. and Gretchen R. P ., Phannaceutical Technology, 2001 ,

25(6), 54.

13. Fell J . T. and Newton J. M., J. Phann. Phannacol. , 1968,20,657.

14. Lerk C. F., Andreae, A.C., Boer A H., Zuurman K ., Hoog P.O.,

Kussendreger K. , Leverink J.Y. and Bolhuis G. K., J. Phann .

Phannacol. , 1983, 35 , 747 .

15. Wong D. Y . T., Wright P. and Autton M. E., Drug Develop. Ind.

Pharm. 1988, 14(15-17),2109.

16. Gunsel W. C. and Lachman L., J. Phann. Sci., 1963 , 52 , 178.

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Review of Literature

17. Batuyois N. H., J. Pharm. Sci., 1966, 55, 727.

18. Mishra AN. and Rao A.B., Ind. J. Phann. Sci., 1998,60(2), 79.

19. Mishra AN. and Rao AB., Ind. J. Pharm. Sci., 1999,61(4), 231.

20. Gohel M. c., Patel L. D., Deepak Murpani and Lakshrny Iyer,

Indian Drugs, 1997,34(6), 1997, 322.

21. Gohel M. c., Patel L. D., Shah D. P., Modi C. J. , Parikh K. N. and

Jogani P. D., lnt. J. Phann. Excip., 1999,14.

22. Gohel M. c., Patel L. D. , Modi C. 1. and Jogani P. D., Pharm.

Techno. Tableting and Granulation Yearbook 1999, 40-46.

23. Gohel M. c., Patel L. D. , Amin A F. , Jogani P. D. , Bajaj S. B. and

Patel G. J., lnt. J. Pharm. Excip., 1999, 86.

24. Juppo AM., Kerviner L., Yliruusi J. and Kristofferson E., J.

Pharm. Pharmacol., 1995, 47,543.

25 . Baykara I. , Duman G., Ozseneor K. S., Ordu S. and Oza!les, B.

Drug Develop. Ind. Pharm., 1991, 17(17),2359.

26. Monedero P. M. c., Munoz-Ruiz, M. V., Velasco Antequera N.

and Munoz M., Drug Develop. Ind. Phann., 1996, 22(7), 689.

27. Bolhuis G. K., Lerk C. F., Bos C. E. and Duineveld C. A. A , Drug

Develop. Ind. Pharm., 1992, 18( 1), 93.

28. Cham T. M., Hsu S. H., Tsai T.R. and Chuo W. H., Drug Develop.

lnd. Pharm., 1997,23(7), 711.

29. Manudhane K. S., Contractor A M. and Kim H. Y., Shangraw R.

F., J. Pharm. Sci., 1969,58(5),616.

30. Leitritz M., Krumme M. and Schmidt P. c., 1. Pharm. Pharmacol. ,

1996,48, 456.

31. Karr J. I., Shiromani P. K. and Savitz J . F., Drug Develop. Ind.

Pharm., 1990, 16, 821.

39

•

1 (47)

Review of Lite rature

32. Bolhuis G. K., Lerk C. F., Bos C. E. and Duineveld C. A A, Drug

Develop. Ind. Phann., 1992, 18( 1),93-106.

33. Patel N. K. , Patel I. J., Cutie A J. and Wadke D. A., Drug

Develop. Ind. Pluum., 1988, 14(1), 77.

34. Augsburger L. L and Shangraw R. F., J. Pharm. Sci., 1966, 55,

4 18.

35. Stephen E., Fraser S. D., Chen A., Michael J. T. and John N. S.,

lnt. J. Phann., 2000, 200, 67 .

36. VarthaJis S. and Pilpel N., J. Phann . Pharmacol. , 1977,29, 37.

37. Lerk C. F. , Bolhuis G. K. and Smedema S. S., Phanna. Acta Helv. ,

1977,52, 33.

38. Ragnarsson G., Holzer A W. and Sjogren 1. , Int. J. Pharm. , 1979,

3, 127.

39. Van Aerde P., Pimhataivoot 1'., Synave R. and Van Severen R.,

Drug Develop. Ind. Phann ., 1987, 13, 225.

40. Moura T. F. , Gaudy D., Jacob M. , Terol A and Chau vet A., Drug

Develop. Ind. Pharm., 1996, 22, 393.

41. Lennartz P. and Mielck J. 8., Int. J. Pharm., 1998, 173,75.

42. Palma S. D., Manzo R. H. and Allemandi D. A , Pharm. Develop.

Tech., 1999, 4, 523.

43. Sindel U., Schweiger A and Zimmermann I. , J. Pharm. Sci. , 1998,

87, 524.

44. Stubberud L. and Forbes R. T., Int. 1. Phann., 1998, 163, 145 .

•

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