Pharmaceutics MCQ question and answer | Pharmacy MCQ question

Steroidal hormones are often administered in the form of implants. These implants are small, solid pellets containing the hormone, which are inserted subcutaneously beneath the skin. They provide controlled and sustained release of the hormone over an extended period, typically ranging from several months to a year. This mode of administration ensures consistent hormone levels in the body, avoiding the need for frequent dosing and offering convenience to the patient.

Let's look at the reaction given: Codeine phosphate ↔ Codeine + Phosphate.
This reaction shows a compound, Codeine phosphate, breaking down into two separate parts: Codeine (which would be the codeine cation) and Phosphate (which would be the phosphate anion). This breaking down into charged particles (ions) is key.

Now let's understand why Option B: Ionic hydrolysis is the correct answer.

Ionic Hydrolysis:
Ionic means the reaction involves ions. Ions are atoms or molecules that have a positive or negative electrical charge. Codeine phosphate is an ionic compound (a salt). When it breaks apart, it forms charged particles (ions).
Hydrolysis comes from "hydro" (meaning water) and "lysis" (meaning to break or split). So, hydrolysis generally means a chemical reaction where water is used to break down a compound.

In the context of pharmaceuticals, when an ionic compound like Codeine phosphate (a salt) is dissolved in water, it dissociates (breaks apart) into its constituent ions (Codeine cation and Phosphate anion). Water molecules surround and stabilize these ions, facilitating the breaking of the ionic bond. This process is often referred to as ionic hydrolysis because water plays a crucial role in enabling the salt to split into its ions.

Let's briefly look at why the other options are incorrect:

Option A: Oxidation
Oxidation is a chemical reaction that involves the loss of electrons or an increase in the oxidation state of a molecule or ion. The given reaction is simply about a salt breaking into its ions, not about losing or gaining electrons in that way.

Option C: Polymerisation
Polymerisation is a process where small repeating units (monomers) join together to form a very large molecule called a polymer. This is not happening in our reaction; instead, a single compound is breaking apart.

Option D: Isomerization
Isomerization is a process where a molecule is transformed into another molecule that has the same atoms but arranged differently (an isomer). The molecular formula remains the same. Here, Codeine phosphate is breaking into two distinct ions, not rearranging its atoms to form a new isomer.

Therefore, the breaking down of Codeine phosphate into Codeine and Phosphate ions, typically facilitated by water, best describes Ionic hydrolysis.

Diatomaceous earth, also known as Kiesighur, is a naturally occurring, soft, siliceous sedimentary rock.
It's composed of the fossilized remains of diatoms, a type of hard-shelled algae.

Now, let's look at the other options:
Kaolin is a type of clay mineral, primarily used as an adsorbent and in pharmaceuticals.
Bentonite is another type of absorbent clay, often used as a suspending agent.
Talc is a mineral composed of hydrated magnesium silicate, commonly used as a lubricant and absorbent powder.

Therefore, the only option that matches the description of diatomaceous earth is Kiesighur.