Conventional dosage forms

Delayed action soHd products are designed like conventional dosage forms to release all their dmg contents at one time, but only after a delayed period. Thus, the duration of action and the blood concentration—time curve is like that of a conventional product. However, the onset time is purposely designed to be long. 

Overcome one or more barriers posed by the available routes of administration to achieve a delivery pattern unachievable by conventional dosage forms. 

FIA has also found wide application in pharmaceutical analysis.214,215 Direct UV detection of active ingredients is the most popular pharmaceutical analysis application of FIA. For single component analysis of samples with little matrix interference such as dissolution and content uniformity of conventional dosage forms, many pharmaceutical chemists simply replace a column with suitable tubing between the injector and the detector to run FIA on standard HPLC instrumentation. When direct UV detection offers inadequate selectivity, simple online reaction schemes with more specific reagents including chemical, photochemical, and enzymatic reactions of derivatization are applied for flow injection determination of pharmaceuticals.216... 

Drug-delivery systems are essentially specialized dosage forms developed to overcome the limitations of conventional dosage forms, such as simple tablets, capsules, injectable solutions, etc. Some of the reasons behind the development of oral DDSs are listed below ... 

Buccal dosage forms can be of the tablet, patch, gel, or ointment type and can be employed for local or systemic delivery. For local deliveiy, conventional dosage forms such as solutions and various types of tablets (immediate release, effervescent, etc.) are more suitable. These forms generally have uncontrolled drug release with subsequent variable absorption and short residence times, and may not provide sufficient bioavailability. Novel dosage forms such as adhesive tablets, patches, gels, and... 

Sustained release - Do not use for initial therapy. Once patients are stabilized on conventional dosage forms, they may be switched to sustained release capsules on a milligram per milligram of total daily dose basis. Administer as a single dose after breakfast or in 2 divided doses 12 hours apart. 

Frequently, the constant release of a drug from pharmaceutical dosage forms enables one to obtain a suitable pharmacological and therapeutic response. However, for therapy of certain pathologies, i.e. some heart and rheumatic diseases, or in the utilization of some drags such as contraceptive steroids and antibiotics, it would be more useful to obtain different plasma levels of the active principle at different times related to painful symptoms or circadian rhythms, etc. In these cases the desired therapeutic results can usually be obtained with frequent administration of conventional dosage forms which lead to a prompt absorption of the active principle. This kind of drag treatment is often compromised by a lack of full compliance by the patient. Until now there have been few systems that allow the release of the active principle in successive pulses at precise and well-controlled time periods [11,12]. 

World Health Organization (WHO) (2001), Stability testing of pharmaceutical products containing well established drug substances in conventional dosage form, WHO Technical Report Series 863, Annex 5, WHO, Geneva. 

Extended Release Extended release products are formulated to make the drug available over an extended period after ingestion. This allows a reduction in dosing frequency compared to a drug presented as a conventional dosage form (e.g., as a solution or an immediate release dosage form). 

Modified Release Dosage Forms Dosage forms whose drug-release characteristics of time course and/or location are chosen to accomplish therapeutic or convenience objectives not offered by conventional dosage forms such as a solution or an immediate release dosage form. Modified release solid oral dosage forms include both delayed and extended release drug products. 

An ideal drug delivery system is one which provides the drug only when and where it is needed, and in the minimum dose level required to elicit the desired therapeutic effects. In practice, such a system should provide a programmmable concentration-time profile that produces optimum therapeutic responses. This goal can only be achieved to a limited extent with conventional dosage forms. 

Specialized drug delivery systems constitute a relatively recent addition to the field of pharmaceutical technology. Up until the 1940s conventional dosage forms essentially comprised ... 

Annual sales of antihypertensive and anti-anginal products using advanced chug delivery technology are estimated to be around 5 billion worldwide at 1995 levels, representing one-sixth or more of all cardiovascular sales. This share will increase in the near term, as sales of older dmgs in conventional dosage forms decline. 

Formulation factors affecting the oral bioavailability from conventional dosage forms such as solutions, suspensions, emulsions, capsules and tablets are described here. 

Conventional dosage forms tablets, capsules, suspensions, emulsions and solutions... 

Conventional dosage forms for oral drug delivery comprise ... 

The seven dmgs and the combination estrogen-progestin product presently approved in the US for delivery by the transdermal route were all well known and available in more conventional dosage forms before their formulation into skin patches . All of these dmgs are extremely potent, none requiring more than about 20 mg per day (and some, much less) for effective therapy. 

Clinical (PK, PD, Safety and Efficacy) Human clinical studies can range in complexity from standard-design PK studies to complicated, long-term efficacy trials evaluating one or more indications in multiple populations. Human PK studies are used as the benchmark for establishing bioequivalence of conventional dosage forms. For traditional pharmaceuticals for which reliance on systemic exposure may not be suitable, PD or clinical safety and efficacy may be performed to show equivalence. 

Liquid, Extended Release A liquid that delivers a drug in such a manner to allow a reduction in dosing frequency as compared to that drug (or drugs) presented as a conventional dosage form. 

Improve drug utilization by applying a smaller drug dose in a controlled-release form to produce the same clinical effect as a larger dose in a conventional dosage form. 

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