Solution dosage forms

Typically less than 3% of topically applied drugs in ocular dosage forms—solutions. 

Oral Dosage Forms Solutions, Suspensions, and Emulsions... 

SVIs are simple formulations compared with other pharmaceutical dosage forms. Solution SVIs contain water, the active ingredient, and a minimal number of inactive added ingredients. Solid SVIs contain the active ingredient and usually one or two added ingredients. Formulation scientists have severe restrictions in number and choice of added substances because of safety considerations. 

Parenteral Long-Acting Dosage Forms Solutions and suspensions... 

Formulation characteristics such as the particle size, surface area, crystal form, and dosage forms (solution, tablet, capsule, suspension, emulsion, gel, and modified released)... 

Composition of the Conventional dosage forms IR solid dosage forms, solutions... 

Liquid Dosage Forms. Simple aqueous solutions, symps, elixirs, and tinctures are prepared by dissolution of solutes in the appropriate solvent systems. Adjunct formulation ingredients include certified dyes, flavors, sweeteners, and antimicrobial preservatives. These solutions are filtered under pressure, often using selected filtering aid materials. The products are stored in large tanks, ready for filling into containers. QuaUty control analysis is then performed. 

Ophthalmic Dosage Forms. Ophthalmic preparations can be solutions, eg, eye drops, eyewashes, ointments, or aqueous suspensions (30). They must be sterile and any suspended dmg particles must be of a very fine particle size. Solutions must be particle free and isotonic with tears. Thus, the osmotic pressure must equal that of normal saline (0.9% sodium chloride) solution. Hypotonic solutions are adjusted to be isotonic by addition of calculated amounts of tonicity adjusters, eg, sodium chloride, boric acid, or sodium nitrate. 

Pharmacology and Uses. Lincomycin hydrochloride (Lincocin) is available in oral dosage forms and as a sterile solution for injection. After... 

The simplest osmotic dosage form, ALZA Corporation s OROS elementary osmotic pump (Fig. 7), combines the dmg and sometimes an osmotic agent in a monolithic core and deflvers the dmg in solution (102). The mass dehvery rate with time dm df) of the dmg solution is described by equation 4, where is the hydrauHc permeabiUty of the membrane, a is the membrane reflection coefficient, Atz is the osmotic pressure gradient, APis the hydrostatic back pressure, A is the area of the membrane, C is the dissolved concentration of the dmg, and b is the membrane thickness. 

Albuterol (also known as salbutamol outside the United States), the most commonly used inhaled short-acting 132-agonist, is a racemic mixture (50 50) of albuterol enantiomers. The R-enantiomer is the active component whereas the S-enantiomer is inactive or may be associated with unwanted effects. Levalbuterol, the pure R-enantiomer of albuterol, is available as a solution for nebulization and as an MDI dosage form. Comparative studies show similar efficacy and safety between levalbuterol and albuterol, but the acquisition cost of levalbuterol is substantially higher. 

Dosage forms IR tablets, solution SR-XL tablets, SR-TD patch IR tablets SR-LA capsules IR tablets IR tablets ER tablets... 

The rationale of the dosage form design (e.g., if a drug is rapidly destroyed in solution at a pH of 2 or below, the design of an oral product must enable the drug to get through the stomach without substantial dissolution)... 

Diarrheal conditions may decrease drug absorption as a result of reduced intestinal residence time. The absorption of several drugs was decreased in response to lactose- and saline-induced diarrhea [145]. Digoxin absorption from tablets was impaired in one subject who developed chronic diarrhea as a result of x-ray treatment [146]. Abdominal radiation or the underlying disease has been shown to reduce digoxin and clorazepate absorption [147]. A dosage form that provides rapid drug dissolution (e.g., solution) may partially resolve this problem. 

The most common extravascular route is oral. When a solution or a rapidly dissolving solid dosage form is given orally, the absorption process often obeys first-order kinetics. In these cases, absorption can be characterized by evaluating the absorption rate constant, ka, using plasma concentration versus time data. 

Whenever a drug is administered by an extra-vascular route, there is a danger that part of the dose may not reach the blood (i.e., absorption may not be complete). When the intravenous route is used, the drug is placed directly in the blood therefore an IV injection is, by definition, 100% absorbed. The absolute bioavailability of an extravascular dosage form is defined relative to an IV injection. If IV data are not available, the relative bioavailability may be defined relative to a standard dosage form. For example, the bioavailability of a tablet may be defined relative to an oral solution of the drug. 

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