Powder Dosage Form - Pharmaceutics 1 PDF

POWDER DOSAGE FORM Pharmaceutics 1 / Lect 3 First Stage / Second Course Powder A pharmaceutical powder: is a mixture of finely divided drugs and/or chemicals in dry form meant for internal or external use. This should differentiated from general use of term powder or powdered which is c...

POWDER DOSAGE FORM Pharmaceutics 1 / Lect 3 First Stage / Second Course Powder A pharmaceutical powder: is a mixture of finely divided drugs and/or chemicals in dry form meant for internal or external use. This should differentiated from general use of term powder or powdered which is commonly used to describe the physical state of a single chemical substance or single drug. Powders are one of the oldest dosage forms and are used both internally and externally. Granules Granules: a dosage form composed of dry aggregates of powder particles that may contain one or more APIs, with or without other ingredients, may be used per se for the medicinal value of their content, or they may be used for pharmaceutical purposes, as in making tablets. The usual size ranges of granules are in the range of 4–12 # sieve. The uses of powders a) Medicated powders for therapeutic effect (limited). b) The use of powdered substances in the preparation of other dosage forms is extensive , such as; 1) Solid dosage forms as tablets and capsules (powdered drugs may be blended powdered excipients). 2) they may be dissolved or suspended in solvents or liquid vehicles to make liquid dosage forms. 3) they may be incorporated into semisolid bases in the preparation of medicated ointments and creams.  to determine Characterization of powders their chemical and physical features Before their use in the preparation, solid materials first are characterized, including; 1. morphology, 2. purity, 3. solubility, 4. flowability, 5. stability, 6. particle size, 7. uniformity, and 8. compatibility with any other formulation components  The mesh size is the number of openings (or wires) per linear inch. Particle size Generally, particles of uniform size are blended more easily. USP uses terms: very coarse, coarse, moderately coarse, fine, and very fine, Related to the proportion of powder that pass through sieve series. Sieves can be referred to either by their aperture (opening) size or by their mesh size (or sieve number). mechanical sieve shaker Opening of Standard Sieves Sieve size # Description 120-400 Very Fine 50-100 Fine 30-40 m. coarse 10-20 Coarse 2-8 v. coarse 4-12 Granules 120-20 Tableting Particle size can influence on many factors 1. Dissolution rate; drug micronization can increase the rate of drug dissolution and its bioavailability 2. Suspendability of particles intended to remain un-dissolved but uniformly dispersed in a liquid vehicle (e.g., fine dispersions 0.5 to 10 µm) 3. Uniform distribution of a drug substance in a powder mixture or solid dosage form to ensure content uniformity. 4. Penetrability of particles intended to be inhaled for deposition deep in the respiratory tract (e.g., 1-5 µm) 5. Lack of grittiness of solid particles in dermal ointments, creams, and ophthalmic preparations (e.g., fine powders may be 50 -100 µm in size). Classification of powders or granules according to its route of administration: 1. Oral powders 2. Inhalation powders 3. Nasal powders 4. Topical powders 5. Dusting powders … etc 1. Oral powders  Oral powders are formulations composed of solid, loose, dry particles of varying degrees of fine particle size.They contain one or more active substances with or without excipients and if necessary, approved coloring matter and flavoring.  They are generally administered in or with water or another suitable liquid, or they may also be swallowed directly 2. Inhalation powders  The powders for inhalation are considered the most effective methods of delivering active ingredients to the lung for the treatment of asthma and chronic obstructive pulmonary disease.  It needs an inhalation device used by the patient at the time of administration where the drug is inhaled as a cloud of fine particles.The drug may be preloaded in the inhalation device or filled into hard gelatin capsules or foil blisters which are loaded into an inhalation device prior to use 3. Nasal powders  Nasal powders have medicinal effects intended for inhalation into the nasal cavity by means of a suitable device.  Some potent drugs are presented in this way because they are rapidly absorbed when administered as a fine powder via the nose.  Also, the drug is mixed with an inert excipient such as lactose that liberates the drug at the administration time. 4. Topical powders  They are used for cutaneous application.  They are solid, loose, dry particles of varying degrees of fineness that contain one or more active pharmaceutical ingredients, with or without excipients, and if necessary, appropriate coloring matter.  Sterile powders for cutaneous application must be formulated using materials and methods that ensure sterility and to avoid the introduction of contaminants and the growth of micro- organisms. 5. Dusting powders  Dusting powders are powders for cutaneous application which have a suitable fineness.  Dusting powders are normally dispensed in glass or metal containers with a perforated lid. So, the powder must flow well from such container to ensure that it can be dusted over the affected area.  The active ingredients must therefore be diluted with materials having reasonably good flow properties such as purified talc or maize starch. Canesten Powder (clotrimazole) is used as an antifungal agent.  They may be used for lubricant purposes such as Talc Dusting Powder.  Bulk Powders Antacids is an example of bulk powders in which the patient takes the dose himself by mixing with water. Powder Excipients The excipients must posses the following properties: 1. Narrow particle size distribution. 2. Good flowability. 16 Powder Excipients 3.Good pressure-hardness profile (if it is used for tablet formulation). 4. They must have high capacity. 5. They must have high bulk density. Bulk density can be measured easily by measuring the volume of certain weight of that diluent. 17 THANK YOU