Solubility equilibrium

Introduction Although, in general, salts are known for their solubility, not all types of salts completely dissociate in water. Some of them partially dissociates and creates a dynamic equilibrium due to the instances when their ions recombine to form the original salts. An example of this is potassium hydrogen tartrate (KHC4H4O6 or KHT). When KHT is placed in water, it partially dissolves and forms K+ and HC4H4O6- ions. This reaction is shown below: KHC_4 H_4 O_6 (s)⇄ K^+ (aq)+HC_4 H_4 O_6^- (aq) (1) The equilibrium constant of reaction (1) is written as Ksp or solubility product constant. The Ksp of reaction (1) is shown in the equation: K_sp=[K^+ ][HC_4 H_4 O_6^-] (1) One of the purposes of the experiment is to determine the Ksp value…

Reservoir Systems consist of a hollow inner core and a polymer membrane, there to control the rate of drug diffusion. Drug diffusion across the membrane is rate limited and controls general drug release rate (Bajpai et al. 2008). For reservoir systems drug release normally remains steady resulting in a zero order profile (Raval, Parikh and Engineer, 2010). Another technology is called the Multiparticulate drug delivery system which consists of microencapsulated granules/beads containing drug…

While it may take time to prepare the standard solutions of known concentration to develop the calibration curve for the spectrophotometer before testing a filtrate, the equations involved in determining the amount of a compound necessary for preparing solutions of specific volume and concentration are simple and do not take a large amount of time to complete. Additionally, when choosing reactants for a reaction before using colourmetirc analysis, one does not need to consult the table of…

SOLUBILITY AND DRUG SOLUBILIZATION 2.1 SOLUBILITY Solubility is commonly related to the bioavailability of the compound of interest,particularly for poorly soluble compounds. Administration of a drug in any dosage form, except solution involves a dissolution step.It is necessary that the drug present in the dissolved state at the site of absorption then only it can be absorbed. It must be soluble in and transported by the body fluids, transverse the required biologic membrane barriers, escape…

Calcium hydroxide (Ca(OH)2), universally referred to as lime water or slaked lime is formed by reacting hydrated lime (calcium oxide, CaO) with water (H2O)[1] CaO (s) + H2O (l) ⇌ Ca(OH)2 (aq) (ΔHr = −63.7 kJ/mol of CaO) Calcium hydroxide is an economically favorable alkaline reagent to neutralize acid as it yields 2 moles of (OH)2 for every 1 mole of Ca(OH)2 (which is slightly soluble in water) when compared to sodium hydroxide [1] and it may separate from the solution ‘constant agitation must…

Evidence and Analysis: The literature Ksp for calcium hydroxide is 5.02×〖10〗^(-6), which is a relatively large Ksp value. This goes against the “rules of solubility” that labels calcium hydroxide as insoluble. According to the “rules of solubility”, calcium hydroxide should not be soluble in water; however, our results reveal that it does have some degree of solubility at standard conditions. We know this because we started with an initial concentration of calcium hydroxide and no concentration…

ABSTRACT Solubility is the phenomenon of dissolution of solid in liquid phase to give a homogenous system.Solubility is one of the important parameter to achieve desired concentration of drug in systemic circulation for pharmacological response to be shown. Poor watersolubledrugs often require high doses in order to reach therapeutic plasma concentrations after oral administration. Low aqueoussolubility is the major problem encountered with formulation development of new chemical entities. Any…

Ka, or the acid dissociation constant, gives a measure to which an acid dissociates in a solution. It also provides a measure of the strength of an acid. If the value of Ka is high, the said acid s largely dissociated, making the acid strong. However, when the value of Ka is small, the little amount of acid is dissociated, making the acid weak. In the experiment, acetic acid (HOAc), is shown to have a computed Ka of 1.1148 x 10-5. It has a very little value meaning it is considered as a weak…

Naturally, PV display the following characteristics: 1. PV can also be used for the removal of certain components in equilibrium reactions. 2. Polymer membrane compaction, a frequent problem in high-pressure gas separation, is not encountered in pervaporation because the feed pressure is typically low.[8] 3. The permeate pressure has to be always lower than the saturation pressure of the permeant to achieve separation.[9] 4. Desorption of the component at the permeate side of the membrane. [10]…

Complexation of Cyclodextrins Cyclodextrins (CDs) are most important carriers because of their semi-natural property as it is produced from a natural material i.e. starch, by simple enzymatic conversion. Solubility and dissolution rate of BCS class II drugs can be improved by addition or by complexation with hydrophilic carriers like cyclodextrins. Cyclodextrins have the capability to form inclusion complexes with the guest molecules i.e. poorly water soluble drugs. The formed inclusion complex…