TABLETS-notes-2010

TABLETS-notes-2010 - University of Wyoming PHCY 6100 Solid...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: University of Wyoming PHCY 6100 Solid Dosage Forms: TABLETS 1. Def. Solid dosage forms prepared by compression or molding of powdered/granulated drugs and with the aid of suitable pharmaceutical excipients. 2. Characteristics: a) Most frequently prescribed commercial dosage form b) Stable, elegant and effective c) Convenient for handling, identification and administration d) Commercially available only in fixed dosage strengths e) Many formats (e.g. Valium® is triangular), sizes, colors, shapes (flat, convex), scored in halves, with elegant engravings, etc (determined by the format of die and punch used, by the amount of fill and amount of pressure applied to the fill). 3. Types a) Compressed Tablets: to be swallowed, made by single compression of all ingredients. b) Multiple Compressed Tablets: for separation of incompatible drugs or for modified release. Multiple-layered tablets: multiple feed and multiple compression of fill within a single die. Tablet-within-a-tablet: core tablet is placed precisely within the die for compression with surrounding fill. c) Sugar-coated tablets: Several layers of colored or uncolored sugar solution (sucrose, gelatin, acacia or PVP=polyvinylpyrrolidone) Time and expertise Final tablet may have an increase of up to 50 % of size and weight of uncoated tablet. Imprinting _ FDA 1995_ product-specific identification codes and distinctive symbols. Polishing: cloth or canvas impregnated with carnauba wax or beeswax or spraying with wax dissolved in acetone. Final tumbling with talc for high luster. d) Film-coated tablets: Thin layer of aqueous or non-aqueous polymer solution (plastic-like material): cellulose acetate phthalate; cellulose ether polymers. Protection, color, durability, less bulkiness, less time consuming. e) Gelatin-coated: capsule-shaped compressed tablet (caplets) f) Enteric coated tablets: Applied to whole tablet or to drug particles or granules: single or multiple layers Materials: shellac, phthalate derivatives 1 University of Wyoming PHCY 6100 Protection of drug, patient gastric mucosa, or enhanced absorption. Based on transit time required for the passage of the dosage form from the stomach into the intestines or based upon the pH of environment. Delayed-release features g) Buccal Tablets: placed in the cheek pouch, dissolve slowly, absorption through the oral mucosa. h) Sublingual Tablets: placed under the tongue, prompt dissolution, absorption through the oral mucosa. i) Lozenges, Troches, Drops or Pastilles: tablets, hard sugar candy-like or gummy-like solid forms, dissolve or disintegrate slowly in the oral cavity, high degree of compression; heat stable active ingredients; usually for local effects. j) Lollipops: sugar-based lozenge on a stick; Fentanyl Actiq to relieve breakthrough chronic cancer pain. k) Chewable Tablets: chewed/dissolved in the mouth, made with creamy base (mannitol, sorbitol, xylitol = sugar-free), negative heat of solution and cool mouth feel upon dissolution; flavored and colored; children & adults who have difficulty swallowing. l) Effervescent Tablets: compression of effervescent salts that liberate carbon dioxide when dissolved in water, should NOT be swallowed whole. m) Molded tablets: molding and soft compaction; hand-operated tablet press. n) Tablets Triturates: “old fashioned” tablets containing small amounts of potent drugs and prepared with minimal compression to allow ease of crushing for compounding or rapid dissolution. o) Rapid Dissolving Tablets (RDT): dissolution within 15-30 sec. and swallowing of the liquid; very water-soluble excipients that attract water into the tablet; children and elderly; inherent problems: drug loading, taste masking and friability Zydis technology = lyophilization (foaming of a mixture of gelatin, sugars, drug, etc and pouring into a mold). DuraSolv, OraSolv, Flashtab, Wowtab technologies = compression (super-disintegrants + small quantity of effervescent material). p) Extended-release Tablets: release of medication in a pre-determined manner over an extended period. q) Vaginal Tablets: = or inserts; uncoated, bullet-shaped or ovoid; plastic inserter devices; local effects. 4. Quality Control for compressed tablets: defined by the U.S.P. a) WEIGHT: determined by the quantity of fill in the die of tablet press. Weight variation for dosage form uniformity: 10 tabs, individual and average weight Assay for homogeneous drug distribution. b) CONTENT UNIFORMITY: 10 tabs; active ingredient is between 85-115% ± 6%. 2 University of Wyoming PHCY 6100 c) THICKNESS: measured through a caliper, a hand gauge or automated equipment; depends on: Diameter of the die Amount of fill Compaction characteristic of fill Pressure applied d) HARDNESS, BREAKING STRENGTH or FRIABILITY: Measurement of pressure/force (in Lb or Kg) required to break each tablet; Depends on type of tablet and degree of compression used during manufacture. Friabilator: measures the tendency of a tablet to crumble (rotating tumbling container). Tablets are weighed before and after rotation and weight loss is determined (maximum loss allowed by USP is 1%). e) DISINTEGRATION: time required for a tablet to disintegrate when placed in an apparatus containing water at 37°C (usually 30 min for compressed tabs) or simulated gastric fluid (1 hr) + intestinal fluid (for enteric-coated tabs). f) DISSOLUTION: In vitro testing Product development Quality assurance during manufacturing Bioequivalence from batch to batch: scale-up batches Mandatory for approval of marketing: FDA and regulatory agencies of other countries. Influences the absorption and bioavailability. 5. Preparation of Tablets (compressed) a) WET GRANULATION Powdered ingredients (drugs + fillers + disintegrating agents + glidants + other excipients) are weighed and blended Sifted (to eliminate clumps) Mixed with a liquid binder or adhesive mixture (10-20% aqueous solution of cornstarch, 25-50% sol. of glucose, molasses, gums such as acacia, sol. of cellulose derivatives, gelatin) Damp mass Pass through screen (#6-8 mesh size)= granules or pellets. Drying in thermostatically controlled oven. Sizing by dry screening (#12-20 mesh) Granules + dry lubricant (Mg/Ca/Zn Stearate, talc, stearic acid) = blending Compression in tableting machine 3 University of Wyoming PHCY 6100 (i) Single-punch tablet press (ii) Rotary tablet machine with multiple punches: high speed production _ lamination and capping ALL-IN-ONE-GRANULATION METHOD: sophisticated machinery; preparation of granulation is by Fluid-bed process or Microwave vacuum process. b) DRY GRANULATION For materials that are degraded in presence of moisture or high heat. Weighing of powdered ingredients (drugs + fillers + disintegrating agents, etc), blending, cohesive properties Powders are compressed in slugging machine or roller compaction (binding agents: methylcellulose or hydroxyl-methylcellulose at 6-12%) Flat “slugs” or pellets Slugs are crushed (mill) and sized (screen) Granules + dry lubricant (Mg/Ca/Zn Stearate, talc) Compression in tableting machine c) DIRECT COMPRESSION Excipients have free-flowing and cohesive properties: Potassium chloride, Methenamine, Dibasic calcium phosphate. d) MOLDING: involves forcing a dampened mass into the cavities of a tablet mold (plastic or metal) consisting of two plates, one with holes and the other with pegs. 6. Tablet dedusting: to remove loose powder; elegance; prior to coating. 7. Tablet Coating: For compressed tablets For protection of drug from air and humidity To protect gastric mucosa of irritating drugs To mask taste, For especial release of drug (enteric coated) To provide aesthetics and distinction to a product (color, imprinting of manufacturer’s symbol or information). Types: (i) SUGAR COATING (ii) FILM COATING (iii) ENTERIC COATING 4 University of Wyoming 8. PHCY 6100 Packaging and Storage a) Containers: bottles, blister b) Light-resistant c) Desiccant packet x cotton ball d) Reduced potency of volatile drugs: nitroglycerin (glass container and no packing materials in contact with tabs). 5 ...
View Full Document

Ask a homework question - tutors are online