The most important physical–chemical parameters are lipophilicity, solubility, acid–base character, and electrochemical redox potential. These properties can be used both in modeling absorption, distribution, and cell permeation, and in the structure-activity relationship correlation to help design active compounds.
Table of Contents
What is physical stability of a drug?
Physical stability refers to changes in the physical characteristics of the formulation ingredients of a drug product such as phase transformation of the drug or excipients.
What are the physical properties of a solution?
Colligative properties of a solution depend on only the total number of dissolved particles in solution, not on their chemical identity. Colligative properties include vapor pressure, boiling point, freezing point, and osmotic pressure.
What properties do drugs need to cross the blood brain barrier?
Drug characteristics that are favorable for crossing the BBB are therefore high lipophilicity, small size and molecular weight, and low hydrogen-bonding potential (i.e., the drug is unionized at physiologic pH).
What is physical form of the drug?
Dosage Form (DF) is defined as the physical form of a dose of a chemical compound used as a drug or medication intended for administration or consumption.
Why are physicochemical properties important in medicinal chemistry?
Physicochemical properties play an important role in modifying the biological activities of many compounds. Thus, pharmacological or therapeutic effects of a drug also relate to its biodistributions or physicochemical parameters of a drug such as: hydrogen bonding. chelation.
What factors affect the stability of medicines?
Common factors that affect this stability include temperature, light, pH, oxidation and enzymatic degradation. Special considerations are also required when dealing with chiral molecules, deuterated internal standards and large biomolecules.
How can drug stability be improved?
Dendrimers formulations to enhance skin drug delivery Presence of dendrimers as an excipient in drug formulations helps to improve drug stability, solubility, and bioavailability. In addition, dendrimers can improve the pharmacokinetic features of drug formulations in a way to develop controlled drug-released systems.
What affects stability?
The position of the centre of gravity of an object affects its stability. The lower the centre of gravity (G) is, the more stable the object. The higher it is the more likely the object is to topple over if it is pushed.
Why are solutions important in our daily life?
Many chemical reactions are carried out in solutions, and solutions are also closely related to our everyday lives. The air we breathe, the liquids we drink, and the fluids in our body are all solutions. Furthermore, we are surrounded by solutions such as the air and waters (in rivers, lakes and oceans).
What factors affect the properties of a solution?
Factors affecting the formation of the solution: Proportion of the solute & the solvent: Solute should be in less quantity and solvent should be more in quantity to dissolve the solute. Particle size of the solute: Small size of particles of the solute dissolve faster.
What are the 3 main properties of a solution?
Properties of a Solution A solution is a homogeneous mixture. The constituent particles of a solution are smaller than 10-9 metres in diameter. Constituent particles of a solution cannot be seen by naked eyes. Solutions do not scatter a beam of light passing through it.
What drugs Cannot pass the blood-brain barrier?
Recent research has found that drugs of abuse, including cocaine, methamphetamine (METH), morphine, heroin, nicotine, and alcohol, cause BBB dysfunction by altering TJ formation and protein expression (Hawkins and Davis, 2005; Abbott et al., 2006).
Why some drugs Cannot cross blood-brain barrier?
The blood–brain barrier (BBB) prevents the brain uptake of most pharmaceuticals. This property arises from the epithelial-like tight junctions within the brain capillary endothelium. The BBB is anatomically and functionally distinct from the blood–cerebrospinal fluid barrier at the choroid plexus.
What Cannot cross blood-brain barrier?
Such substances include lipid-soluble substances (e.g., oxygen, carbon dioxide). Hydrophilic substances, for example, hydron and bicarbonate, are not permitted to pass through cells and across the blood-brain barrier.
What is the importance of physical pharmaceutics?
It forms the basis for design, manufacture, and distribution of drug products and serves as the foundation for the stable and proper use of medical drugs. It covers areas such as solubility, pharmacokinetics and drug delivery. Physical pharmacy serves as principles that guide the pharmaceutical developments.
What are the different forms of medication?
- Liquid. The active part of the medicine is combined with a liquid to make it easier to take or better absorbed.
- Tablet. The active ingredient is combined with another substance and pressed into a round or oval solid shape.
- Capsules.
- Topical medicines.
- Suppositories.
- Drops.
- Inhalers.
- Injections.
What is pharmaceutical physical chemistry?
The Pharmaceutical Physical and Analytical Chemistry group applies physical chemical approaches in combination with advanced analytical techniques to advance understanding of fundamental processes in drug design, development and characterization.
How physicochemical properties affect drug action?
Lower concentration surfactants reduce the surface tension, which increases the rate of absorption of the drugs. This is dependent on chemical structure, effect on biological membrane, concentration, and micelle formation of the surfactant. Hence affecting the physicochemical property of the drug.
Which physicochemical properties influence the action of drug is?
2. DEFINITION: The ability of a chemical compound to elicit a pharmacological/ therapeutic effect is related to the influence of various physical and chemical (physicochemical) properties of the chemical substance on the bio molecule that it interacts with.
Which is the most important physicochemical properties affecting drug action?
The most well known property is lipophilicity, often defined as the partition coefficient between octanol and water. This property is related to passive diffusion across cell membranes, solubility, interaction with receptors, metabolism and toxicity.
What are the 4 factors of stability?
Size of the base of support. support. maintain equilibrium. support.
Why is chemical stability important?
Stability is an essential quality attribute for pharmaceutical formulations. Evaluation of drug stability can prevent toxicity and increase safety, efficacy and quality of the final drug product. In this work, various factors affecting stability of both small molecule and biopharmaceutical compounds were investigated.
How are drugs stabilized?
The most universal approach to stabilizing drug components is to lower the temperature. Reduction of the temperature normally slows down not only enzymatic but also spontaneous reactions. For spontaneous degradation reactions, the effectiveness of temperature control depends on the activation energy.
Why drug stability testing is important?
The purpose of stability testing is to provide evidence on how the quality of a drug substance or drug product varies with time under the influence of a variety of environmental factors such as temperature, humidity, and light, and to establish a re-test period for the drug substance or a shelf life for the drug …