SP PHAR 6112 Final Exam Chicago State University School of Pharmacy

Explanation:

Correct Answer: (A) Inserts

Vaginal tablets are officially termed vaginal inserts in pharmaceutical terminology. They are solid dosage forms specifically designed to be inserted into the vaginal cavity where they dissolve, melt, or disintegrate to release the active drug for local treatment of conditions such as vaginal infections, atrophic vaginitis, or contraception. The United States Pharmacopeia (USP) classifies vaginal tablets under the broader category of vaginal inserts.

Why Other Options are Incorrect:

B. Douches — Vaginal douches are liquid preparations used to rinse or cleanse the vaginal canal. They are solution-based products, not solid dosage forms, and are entirely different from vaginal tablets in both form and function.

C. Gelatin — Gelatin refers to a material used in the manufacturing of capsule shells and certain suppository bases. It is not the pharmacological term used to describe vaginal tablets as a dosage form category.

D. Capsules — Vaginal capsules do exist as a separate dosage form from vaginal tablets. While both are inserted vaginally, they are distinct formulations. Vaginal tablets are specifically referred to as inserts, not capsules.

Explanation:

Correct Answer: (D) The transdermal unit contains more drug than is intended for delivery into the body over the prescribed period of use

Transdermal patches are deliberately designed to contain a significant excess of drug beyond what will actually be delivered during the prescribed wear period. This excess drug reservoir is necessary to maintain a consistent concentration gradient across the skin throughout the entire duration of use, ensuring a constant and controlled rate of drug delivery. For example, a fentanyl patch may contain several milligrams of drug but only delivers micrograms per hour to the patient.

Why Other Options are Incorrect:

A. The transdermal unit should always be placed at the same site — This is incorrect and actually dangerous. Patients are instructed to rotate application sites with each new patch to prevent local skin irritation, sensitization, and tissue damage from repeated drug exposure at the same location.

B. The transdermal unit may remain attached after the labeled delivery period because drug absorption ceases — This is false and dangerous. After the labeled delivery period, residual drug remains in the patch and can still be absorbed. Leaving a patch on beyond its prescribed time can lead to overdose and toxicity, particularly with potent drugs like fentanyl.

C. Skin thickness is not a factor in drug absorption — This is incorrect. Skin thickness significantly affects transdermal drug absorption. Thinner skin (such as on the inner wrist or behind the ear) allows for greater drug permeation, while thicker skin (such as on the palm or sole) provides a greater barrier to drug penetration.

Explanation:

Correct Answer: (A) Crystallization

Crystallization is a fundamental pharmaceutical manufacturing process used both to form and to purify active pharmaceutical ingredients (APIs). In this process, a drug substance is dissolved in a solvent at high temperature and then allowed to cool or concentrate, causing the pure drug to precipitate out as highly ordered crystals. Impurities remain in solution and are separated from the purified drug crystals. Crystallization is widely used in pharmaceutical production because it yields APIs of high purity, defined crystal structure, and consistent physical properties such as melting point, solubility, and bioavailability.

Why Other Options are Incorrect:

B. Oxidation — Oxidation is a chemical degradation process in which a drug molecule loses electrons or reacts with oxygen, leading to chemical breakdown and loss of drug potency. It is a cause of pharmaceutical instability, not a method of API formation or purification.

C. Racemization — Racemization is a chemical process in which an optically pure enantiomer (chiral drug) is converted into an equal mixture of both enantiomers (a racemic mixture). This is generally an undesirable process in pharmaceutical production as it can reduce drug efficacy and introduce unwanted stereoisomers with different pharmacological profiles.

D. Reduction — Reduction is an electrochemical process involving the gain of electrons by a molecule. While reduction reactions are used in some synthetic chemistry steps, it is not specifically identified as a general process for the formation and purification of APIs in the way that crystallization is.

Explanation:

Correct Answer: (A) Sodium salicylate

Sodium salicylate is the sodium salt of salicylic acid and is used pharmaceutically as an analgesic, anti-inflammatory, and antipyretic agent. It is an active pharmaceutical ingredient, not a gelling agent or excipient. It has no gel-forming properties and does not contribute to the viscosity, consistency, or structure of pharmaceutical gel formulations.

Why Other Options are Incorrect:

B. Tragacanth — Tragacanth is a natural polysaccharide gum obtained from Astragalus plants. It is a well-established natural gelling and thickening agent used in pharmaceutical gels, emulsions, and suspensions.

C. Carbomere (Carbopol) — Carbomere is one of the most widely used synthetic gelling agents in pharmaceutical topical formulations. When neutralized, it forms highly viscous, transparent gels used extensively in cosmetic and pharmaceutical products.

D. Methylcellulose — Methylcellulose is a semi-synthetic cellulose derivative that forms viscous gels in aqueous solutions. It exhibits unique reverse thermal gelation (gels upon heating, liquefies upon cooling) and is widely used as a gelling and viscosity-enhancing agent in pharmaceutical preparations.

Explanation:

Correct Answer: (C) Active hepatic first pass

The three principal processes that determine urinary excretion of a drug are glomerular filtration, active tubular secretion, and tubular reabsorption — all of which occur in the kidney as illustrated in the attached nephron diagram. The hepatic first pass effect refers to the metabolism of a drug by the liver before it reaches systemic circulation and is a process of hepatic metabolism, not renal excretion. It has no role in determining urinary drug excretion.

Why Other Options are Incorrect:

A. Active tubular secretion — This is a primary renal excretion process where drug molecules are actively transported from the peritubular capillaries into the renal tubular lumen for excretion in urine.

B. Active or passive tubular reabsorption — Tubular reabsorption is a key process in renal drug excretion where drug molecules in the tubular filtrate are reabsorbed back into the bloodstream, reducing the amount excreted in urine.

D. Glomerular filtration — Glomerular filtration is the first and primary step in renal drug excretion, where unbound drug molecules are filtered from the blood through the glomerular capillaries into the Bowman's capsule to begin the process of urinary excretion.

Explanation:

Correct Answer: (B) It can exist in many crystalline structures

Polymorphism in pharmaceutical science refers to the ability of a compound to exist in more than one distinct crystalline form while having the same chemical composition. Cocoa butter (Theobroma oil) exhibits polymorphism by existing in four main crystalline forms (alpha, beta-prime, beta, and gamma), each with a different melting point. This property is pharmaceutically significant because overheating cocoa butter during suppository preparation can cause it to convert to a less stable polymorphic form with a lower melting point, leading to suppositories that melt at room temperature and fail to maintain their shape.

Why Other Options are Incorrect:

A. Different chemical same crystal structures — This is the inverse of the correct definition. Polymorphism means the same chemical compound existing in different crystal structures, not different chemicals sharing the same crystal structure.

C. It has multiple dissociation constants — Multiple dissociation constants (pKa values) describe the acid-base chemistry of a compound and refer to how a molecule releases protons at different pH levels. This is unrelated to polymorphism and crystalline structure.

D. It solidifies at room temperature — While cocoa butter does solidify at room temperature, this describes its physical state at a given temperature, not the concept of polymorphism. Many substances solidify at room temperature without being polymorphic.

Explanation:

Correct Answer: (C) 1.5 × 10⁶ Units

From the label: the container holds 15 grams of Nystatin Topical Powder at a concentration of 100,000 units per gram. Total units = 100,000 units/gram × 15 grams = 1,500,000 units = 1.5 × 10⁶ units. This is the total number of Nystatin units in the entire container.

Why Other Options are Incorrect:

A. 10 × 10⁸ Units — This equals 1,000,000,000 units (1 billion), which is far greater than what is contained in a 15-gram container at 100,000 units per gram.

B. 10 × 10⁵ Units — This equals 1,000,000 units (1 million), which is close but does not precisely match the correct calculation of 1,500,000 units (1.5 × 10⁶).

D. 15 × 10⁸ Units — This equals 15,000,000,000 units, which is an enormous overestimation and mathematically inconsistent with the label information provided.

Explanation:

Correct Answer: (B) PEG

Polyethylene glycol (PEG) is a water-soluble, synthetic hydrophilic base used in suppository and pharmaceutical formulations. It is emphatically not an oleaginous (fatty) base. PEG dissolves in body fluids rather than melting at body temperature and is completely miscible with water, making it fundamentally different from fatty oleaginous bases which are water-insoluble and lipid-based.

Why Other Options are Incorrect:

A. Oleic acid — Oleic acid is a monounsaturated fatty acid that is a natural component of many animal and vegetable fats and oils. It is a classic example of a fatty/oleaginous substance used in pharmaceutical formulations.

C. Cocoa Butter — Cocoa butter (Theobroma oil) is the most widely used natural oleaginous suppository base. It is a triglyceride-rich fat that is solid at room temperature and melts at body temperature, making it a definitive fatty base.

D. Stearic acid — Stearic acid is a saturated long-chain fatty acid that is solid at room temperature. It is widely used as a fatty base and emulsifying agent in pharmaceutical and cosmetic preparations and is clearly an oleaginous substance.

Explanation:

Correct Answer: (B) Vaginal Inserts

The product label shown in the attachment is Grastatine Vaginal Inserts (Nystatin Vaginal Inserts). Nystatin vaginal inserts are solid, compressed tablet-like dosage forms inserted into the vaginal cavity for the local treatment of vaginal candidiasis. Unlike suppositories that melt at body temperature, vaginal inserts dissolve or disintegrate in vaginal fluids to release nystatin for antifungal action against Candida species. The label clearly confirms this classification as vaginal inserts.

Why Other Options are Incorrect:

A. Vaginal Suppositories — Vaginal suppositories are typically made with a fatty or water-soluble base that melts or dissolves at body temperature. Nystatin is formulated as a compressed vaginal insert, not a melting suppository base formulation.

C. Urethral Suppositories — Urethral suppositories are inserted into the urethra for very specific indications such as erectile dysfunction treatment. Nystatin has no clinical indication for urethral delivery.

D. Rectal Suppositories — Rectal suppositories are designed for rectal insertion to treat local rectal conditions or for systemic absorption. Nystatin vaginal inserts are specifically formulated for intravaginal antifungal therapy, not rectal use.