The Rate a Drug is Released in the Body

Absorption – “How the drugs enter the circulation process through the body, and how they resist general breakdown by the stomach, liver, and the intestines”. Some of the factors that affect the absorption of drugs in the body is as follows, “acidity of the stomach, Physiochemical properties, Presence of food in the stomach or intestine, and Routes of administration”,

Based on ¨Principles of Pharmacokinetics¨, ¨pharmacokinetics is the study of absorption, distribution, metabolism, and excretion¨ (Ratain 2003). In other words, the drug's pharmacokinetics determines the duration and the intensity of the effect on the body. Absorption rate can be affected by the drug itself, such as: rate of dissolution, lipid solubility, and route (VandeWaa 2016). The absorption process starts by the route of admission, in this case oral. The oral, or by mouth, route of administration for drugs is the most common. When a pill is taken by mouth, it travels down to the stomach, were most pills dissolve. While in the stomach, some kinds of pills are absorbed into the stomach lining, but some move on to the small intestine. Every pill eventually ends up in the bloodstream and circulate through the body to tissues and organs (Howell 2017). Once passive diffusion occurs, the cells absorb the molecules of the medicine. Then, the molecules of the medicine will exit the cells and travel in the bloodstream for the distribution process.

After oral administration, APAP is rapidly absorbed by the GI tract; its volume of distribution is

Among other approaches tried by scientists, colloidal systems like liposomes, polymeric nanoparticles etc., have shown promise but not many products have made it to the market (7). Nanoparticulate drug delivery systems are gaining much popularity in recent years. Among these, nanoparticulate drug delivery systems from biodegradable and biocompatible polymer are an interesting option for controlled drug delivery and drug targeting (8). Amongst the various drug-delivery systems, solid lipid nanoparticle (SLN) and nanostructured lipid carrier (NLCs) are potentially attractive choices due to their natural components and easily scaled-up formulation processes. In addition, their hydrophobic core provides a suitable environment for entrapment of hydrophobic drugs (9). Among the important technological advantages of nanoparticles as drug carriers are: high stability (i.e. long shelf life), high carrier capacity (i.e. many drug molecules can be incorporated into the particle matrix), feasibility of incorporation of both hydrophilic and hydrophobic substances, and feasibility of variable routes of administration (10). NLCs are kind of lipid-based nanoparticles, which has the advantages of biodegradable, brain targeting, well-recognized safety profile by drastically reducing drug-related toxicities through reduction of nonspecific biodistribution (11). NLCs consist of an unstructured solid lipid

Many molecules, particularly peptides and polypeptides are physically embedded in polymers to create a complex network of interconnecting pores through which the drug could subsequently diffuse. The pore structure and polymer composition is controlled in order to design systems that release the drug at nearly any rate and for nearly

Oral forms of cephalosporins are well absorbed from the gastrointestinal (GI) tract. Absorption is delayed by food, except for in oral ester prodrugs where absorption is

7. What is the reason for manufacturing a drug as an enteric-coated tablet? (2 points)

"Absorption depends on the drug’s ability to cross cell membranes and resist extensive breakdown by the stomach, liver, and intestines.

route. It may be in the form of capsules, powders or tablets. There are some things that may hamper the process of absorption, such as different types of medications being used at the same time. For example, some antibiotics are not absorbed

Pharmacokinetics (PK) is a complex process even for healthy patients. The whole body, as a system, remains unpredictable in many of its responses to drugs. That being said we have elucidated many of the body processes and have designed drugs and drug therapy regimens around new evidence and models. PK is broken down into four pats: administration, distribution, metabolism, and excretion. Absorption refers to the drug entering the body; distribution to the spread of the drug to tissues, organs and throughout the blood; metabolism is the processing of drugs by enzymes in the body, such as the cytochrome P450 liver enzymes; and excretion is drug removal from the body. As the body ages, all of these areas is affected.

However, PPIs cannot be simply dropped into the stomach because they will not reach their target. They are prodrugs that are activated in the presence of an acidic environment. The drugs must be absorbed by the small intestine and reach the circulation via parietal cells and be exported to the canaliculi of the stomach so that the first nucleophile they see is the PPI. Enteric coatings or admixture with bicarbonate are ways to protect the prodrug from acid before they are systemically

This review presents a survey of challenges associated with formulating MDIs as solution or suspension products with one or more drugs, while considering the physicochemical properties of various excipients and how the addition of these excipients may impact overall product performance of the MDI. Propellants, volatile and nonvolatile cosolvents, surfactants, polymers, suspension stabilizers, and bulking agents are among the variety of excipients discussed in this review article. Furthermore, other formulation approaches, such as engineered excipient and drug-excipient particles, to deliver multiple drugs from a single MDI are also evaluated. The device hardware includes a canister that is appropriately sized to contain sufficient formulation for the required number of doses, a metering valve capable of delivering a consistent amount of drug with each dose delivered, an actuator mouthpiece that atomizes the formulation and serves as a conduit to deliver the aerosol to the patient, and often an indicating mechanism that provides information to the patient on the number of doses

List and describe the four factors that affect the rate of drug distribution. How will you explain an adverse effect to a patient? How is this different than a side effect?

The hygroscopic nature of a drug is a risk for good aerosolization since moisture uptake can result in agglomeration (Hoppentocht et al., 2015). On the other hand, hydrophobic coating improves the flowability of cohesive powders (Hickey et al., 1990; Yang et al., 2005).

The selection of an appropriate dosage form is critical because a dosage form with poor drug delivery can make a useful drug worthless. A large percent of these new chemical entities (NCEs) in addition to many existing parent drugs often show poor solubilization behaviour which lead to poor oral bioavailability with wide intra- and inter- subject variation and present formulators with considerable technical challenges. [1] Many approaches have been meticulously explored to improve the oral bioavailability of such drugs including particle size reduction (micronization or nanosizing), complexation, and modification of the physicochemical properties. [2, 3]