Uy, Alyssa V. 2BPh
•
effervescent salts that release gas when in contact with water.
CHAPTER 8 – Tablets
This tablet contains medicinal substance which dissolves rapidly when in contact with water.
Tablets - solid dosage forms usually prepared with the aid of suitable pharmaceutical excipients •
vaginally contain features most applicable to their routes of administration. •
and lactose are used for diluent.
Compressed Tablets (C.T.) - manufactured with tablet machine capable of exerting great pressure or compacting the powdered or granulated tableting material. DILUENTS, BINDERS, DISINTEGRANTS,
•
dissolved in suitable vehicle, sterility attained, and the injection performed. The advent of prefabricated injectable products and
Multiple Compressed Tablets (MCT) – prepared by subjecting the
disposable syringes declined its use.
fill material to more than a single compression, the core (inner) and shell (outer) •
to patients. It contains large amount of potent subs. enabling the
uncolored sugar layer, water soluble and quickly dissolved after
pharmacist to obtain pre-measured amounts. For compounding
swallowing. Purposes: to protect the enclosed drug from the
multiple dosage units.
environment and to provide a barrier to objectionable taste and smell of the drug. Disadvantages: time and expertise needed in
•
•
controlling features like coating and other ways.
polymer capable of forming a skin-like usually colored film over •
use of lyophilization techniques, soft direct compression, or the
time consuming to apply.
use of water-soluble excipients designed to “wick” water into the tablet for rapid disintegration.
Gelatin Coated Tablet – capsule-shaped compressed tablet with 1/3 the size of capsule with the same amount of fill, more ease in swallowing & more tamper evident. (GelCaps)
•
•
over an extended period of time.
designed to pass the stomach to the intestines where the tablet •
is destroyed by gastric acid
b)
is irritating to the gastric mucosa
c)
by-passed the stomach enhances the drug
to fit smugly into plastic inserter devices. They contain antibacterials (against Hemophilia vaginitis) and antifungals (against Candida albicans) The physical features of compressed tablets are varied; its
absorption in the intestines •
diameter and shapes are determined by the die and punches used in the compression. The less concave the punch, the more flat the
Buccal tablets – flat, oval tablets intended to be dissolved slowly
resulting tablets . Punches with raised impressions will have
in the buccal pouch. It is for oral absorption of drugs destroyed by
recessed impressions on the tablets.
gastric acid or poorly absorbed in the GI tract. •
Sublingual Tablets – designed to erode promptly underneath the tongue for rapid drug effect.
•
•
Lozenges or troches – disc-shaped solid forms containing a
Vaginal Tablet/Inserts – uncoated and bullet- or ovoid- shaped tablets for localized effect. Prepared by compression and shaped
when drug substance: a)
Extended Release Tablet (E.R.) /Controlled Release (C.R.) – designed to release their medication in a predetermined manner
Enteric-Coated Tablets (E.C.T.) – have delayed release features, will disintegrate allowing drug dissolution & absorption. Needed
Instant Disintegrating/Dissolving Disintegrating/Dissolving Tablets – characterized to dissolve within 10 seconds to 1 minute. This is possible with the
film coating over sugar coating: more durable, less bulky and less
•
Immediate Release Tablets (I.R.) – designed to disintegrate and release their medication and therefore are devoid of special rate
Film-Coated Tablets (F.C.T.) – coating is made of thin layer of a the tablet. Polymer is cellulose acetate phthalate. Advantages of
Dispensing Tablets (D.T.) or compounding tablets – used by pharmacists when compounding prescriptions and not dispensed
Sugar-Coated Tablet (S.C.T.) – the coating maybe colored or
the coating process and increased shipping costs
Hypodermal Tablet (H.T.) – used by physicians for extemporaneous preparations of parenterals. It is meant to be
ANTIADHERENTS/ GLIDANTS/LUBRICANT, COLORANTS/FLAVORANTS
•
Compressed Tablet Triturate (CTT) – prepared by compression (limited pressure) usually containing potent substance. Sucrose
Types of Tablets: T ablets:
•
Molded Tablet Triturate (M.T.T.) – small & cylindrical, very soft, soluble & designed to dissolve rapidly.
Majority are administered orally, orally, while others sublingually, sublingually, buccally or
•
Effervescent Tablets – prepared by compressing granular
Quality Standards and Compedial Requirements: •
USP Weight Variation Test: Test : 10 tablets are individually weighed and average weight calculated.
•
Content Uniformity: Uniformity : Dosage units are assayed individually and
medicinal substance in a hard candy or sugar base. Meant to
requires that each dosage unit is 85% - 115% of the label claim
dissolve slowly for localized effect or systemic effect
(S.D. is less than 6%)
Chewable Tablets – have rapid disintegration when chewed or allowed to dissolve in the mouth, have a creamy base usually specially flavored and colored mannitol. Meant for large-sized tablets given to children and adults with difficulty in swallowing solid dosage forms
•
Tablet thickness is determined by a.
the diameter of the die
b.
the amount of fill
c.
the compactibility of the fill material
d.
the force of pressure applied during compression.
Page 1 of 3
•
Tablet thickness is measured by a hand gauge .
•
Tablet hardness affects its disintegration & drug absorption. The
are withdrawn for chemical analysis. Samples must meet the requirement stated in the monograph.
•
greater the pressure, the harder the tablet . It should be hard
Pooled dissolution testing – samples coming from different batches placed
enough to resist breaking during the normal handling and yet soft
in individual dissolution vessel in the apparatus or multiple dosage units in a
enough to disintegrate properly after swallowing.
single vessel. This recognizes the concept of batch characteristics.
A force of 4 kilograms as determined by hardness tester is minimum requirement for a satisfactory tablet.
•
Tablet friability – the tendency to crumble by allowing it to roll and fall within the rotating machine (friabilator). A maximum weight loss of not more than 1% of the weight of the tablets being
3 methods for compressed tablet:
Wet Granulation: Granulation: Weighing and blending of ingredients (A.I. &
tested is acceptable.
adjuvants) + liquid binder screen the damp mass (Sieve 6-8)
Tablet Disintegration Test – uses a basket-rack assembly
compress
dry size the granules (Sieve 12-20) + lubricant and blend •
containing 6 open ended transparent tubes held vertically upon a
Fillers – Fillers – lactose and mi crocrystalline cellulose
10-mesh stainless steel wire screen.
Binder – – to facilitate adhesion of powder particles.
Starch, povidone, methylcellulose. The basket is raised and lowered in the immersion fluid (water at o
37 C) at a frequency of 29-32 times per minute . Result: the
Flavorant and colorant are added to binder.
Lubricant – – to improve the flow of granules from the
residue of the tablet on the screen is a soft mass having no
hopper to the die; prevent adhesion to the punches
palpable inner core . Disintegration time ranged from 2 mins. to 4
and die during compression; reduce friction between
hours depending upon the monograph.
tablet and die’s wall during tablet ejection and provide
tablet sheen. Calcium and magnesium stearate are
For enteric coated tablets , test is done in a simulated gastric fluid
examples.
for 1 hr. No sign of disintegration must be seen . They are immersed in a simulated intestinal fluid for the time stated in the
All-In-One Methods:
monograph where they disintegrate completely. •
1)
which performs the blending, granulating,
Tablet dissolution test - Uses:
drying into 1 continuous process
a.
guides formulation and product development
b.
performance of manufacturing process can be
2)
Consistent results assure bioequivalence from batch to batch
d.
As a requirement for regulatory approval
– Its goal to provide a reasonable prediction or correlation with
using microwave
Dry Granulation – the powder mixture is compacted to large pieces and broken down or sized into granules
High Solubility and High Permeability – IVIVC
b)
Low Solubility and High Permeability – IVIVC
c)
High Solubility and Low Permeability – limited IVIVC
d)
Low Solubility and Low Permeability – none
Active ingredient or diluent must have cohesive properties.
the product’s in vivo bioavailability.
a)
Microwave Vacuum Process – Process – powder mix
is mixed, wetted, agglomerated and dried
monitored by it (quality assurance) c.
Fluid-bed Process – Process – fluid-bed granulator
Advantages: For materials that are degraded by moisture or by elevated temperature during drying
Steps in Dry Granulation: Weighing & blending powder mix slugging sizing + lubricant compression
Tableting machine – machine – compress tablet formulation
within a steel die cavity by the pressure exerted by the In (a) IVIVC is expected if the dissolution time is slower then
movement of the two steel punches (upper and
gastric emptying time (limiting factor).
lower).
•
Imperfections of tablets:
Dissolution Test Apparatus consists of: 1.
variable stirrer motor
2.
stainless basket on a stirrer shaft (Apparatus I) or a
a)Laminations – horizontal striations
b)
Tablet capping – the top of tablet separates from the whole
paddle as stirrer (Apparatus II) 3.
a)
1-L vessel glass with a cover having the shaft of the
c)
Tablet splitting
a)
particles has no time to bond due to
Reasons:
stirrer fitted at the center port, with 3 ports for samples and 1 port for the thermometer 4.
fast high speed production b)
air is entrapped during direct
c)
punches not clean
d)
aging
Water bath to maintain the temp. of the medium in the vessel o
o
Dissolution medium is placed in the vessel at 37 C + 0.5 C. The stirrer is
compression
rotated at speed specified and at stated intervals; samples of the medium
Page 2 of 3
Direct Compression – appropriate for chemicals with flowing and
b)
more uniform coating
cohesive properties
c)
uses less coating material resulting to
Tablet Deduster – – to remove traces of loose powder
Tablets are coated:
lighter, smaller and easy to swallow tablets
adhering to the tablets following compression. d)
less expensive to package and ship
Packaging and Storage:
1) to protect protect from air and/or humidity a) Use tight, light resistant (amber) containers,
2) mask the taste
if adversely affected by light
3) provide characteristics of drug release
b) Store in places of low humidity and protected
4) to provide aesthetics or distinction to the product
from extreme temperature
Sugarcoating – tedious, time-consuming and needs
c) Use desiccant pellet is affected by moisture
expertise of qualified technician and the product doubles the size and wt.
Oral administration of solid dosage forms
Film coating – coating – provides a thin, skin-tight coating of a
Lozenges – by compression or molding. Meant to dissolve slowly in the
plastic material over the compressed tablet.
mouth for localized effect.
Components:
Impact of Changes on Solid dosage forms: 1.
Changes in formulation
– to produce thin smooth film. Cellulose a) Film former –
a) active ingredients
acetate phthalate
b) excipients
b) Alloying substance – substance – to provide water solubility/
d) addition of new excipients
c) their quantities permeability for body fluids to penetrate through and make the drug available. Polyethylene glycol
2.
Changes in methods of manufacturing a) new machineries
– to produce elasticity/flexibility to the c) Plasticizer –
coating & provide durability. Castor oil
Advantages: Size and wt. almost the same as the tablet, more resistant to destruction by abrasion, markings can be embossed on the coating.
b) different steps in manufacturing c) different in process controls, tests or assay methods d) production of different batch sizes e) use of different product reprocessing procedures f) suse of different manufacturing sites
Enteric coating – coating – maybe accomplished through coating
with enough thickness or coating which allow dissolution at a pH 4.9 or higher. Example is shellac
Fluid – Bed Bed or Air Suspension Coating – Coating – spray coating of
powder, pellets, granules or tablets held in suspension by a column of air
Depending where the coating solution come from: a) Wurster – the bottom of the cylinder b) Top spray –sprayed downward c) Tangential – spray techniques – rotary fluid bed coater
Top spray – – recommended for taste masking, enteric
release and barrier film on tablets. Bottom spray – for sustained release and enteric release Tangential – Tangential – layering coating, sustained and enteric
releases
Compression Coating Coating – – the coating material
(granulation or powder form) is compressed into the tablet core.
Advantages: a)
It is anhydrous process appropriate for drugs affected by moisture
Page 3 of 3
