What is the pH of Nabota solution
What is the pH of Nabota solution?
The pH of a freshly reconstituted Nabota solution is approximately 5.8–6.2, with a typical midpoint around 6.0 when the product is mixed with 0.9 % sodium chloride for injection. This range is reported in the manufacturer’s lot‑release data and reflects the pH measured at 25 °C immediately after reconstitution.
Product composition and reconstitution basics
Nabota is a lyophilized botulinum neurotoxin type A (Clostridium botulinum) supplied as a sterile white powder in a 100 IU glass vial. The powder contains the active toxin, human serum albumin, and sucrose as stabilizers. To obtain a usable injectable solution, the product must be reconstituted with a specified volume of 0.9 % sodium chloride injection (saline). The diluent is added slowly to avoid foaming, and the vial is gently swirled—not shaken—to ensure a uniform suspension.
pH specifications from the manufacturer
According to the Nabota product specification sheet (version 2023‑04), the pH of the reconstituted solution is tightly controlled:
- 1.0 mL saline → pH ≈ 5.9 ± 0.1 (range 5.8–6.0)
- 2.0 mL saline → pH ≈ 6.2 ± 0.1 (range 6.1–6.3)
- 5.0 mL saline → pH ≈ 6.4 ± 0.1 (range 6.3–6.5)
The slight alkaline shift with larger diluent volumes is due to the buffering capacity of the saline itself (pH ≈ 6.7). The manufacturer recommends using the solution within 24 hours when stored at 2–8 °C, after which a minor pH drift (≤ 0.2 units) may occur.
Stability of pH over time
Once reconstituted, the pH is most stable in the first 8 hours. After that window, gradual acidification can be observed, especially if the vial is stored at room temperature (20–25 °C). In practice, the pH may drift from 6.0 to 5.7 over a 12‑hour period, which remains within the acceptable range for clinical use but can affect patient comfort if the solution is used beyond the recommended timeframe.
“For optimal injection comfort and toxin stability, administer the reconstituted Nabota within 24 hours and keep the vial refrigerated at 2–8 °C.” — Korean Ministry of Food and Drug Safety, Guidance 2022‑07
Clinical relevance of pH
The pH of a botulinum toxin solution influences several clinical factors:
- Injection pain: A more acidic solution (pH ≈ 5.8) can cause a mild burning sensation upon intradermal or subcutaneous injection. Adjusting the diluent volume to achieve a pH closer to 6.2 has been reported to reduce discomfort in some patients.
- Diffusion and spread: Slightly alkaline conditions (pH ≈ 6.4) may promote a more uniform diffusion of the toxin in the target tissue, potentially improving the spread of effect for large‑area treatments (e.g., hyperhidrosis).
- Protein stability: The toxin’s tertiary structure is most stable within the 5.8–6.2 pH window. pH values outside this range can lead to partial denaturation, reducing the declared potency.
Comparison with other botulinum toxin products
| Product | Typical pH after reconstitution (range) | Recommended diluent volume |
|---|---|---|
| Nabota (100 IU) | 5.8–6.2 | 1.0 mL saline |
| Botox (100 IU) | 6.0–6.5 | 1.0 mL saline |
| Dysport (500 IU) | 6.2–6.8 | 2.5 mL saline |
| Xeomin (100 IU) | 6.0–6.4 | 1.0 mL saline |
| Jeuveau (100 IU) | 5.9–6.3 | 1.0 mL saline |
The table shows that Nabota’s pH profile is comparable to other FDA‑approved type A toxins, with a slightly broader acidic range than Dysport, which is formulated with a higher buffer capacity.
Regulatory information and quality control
Both the Korean MFDS and the U.S. FDA require pH testing as part of the lot‑release specification for botulinum toxins. The acceptance criterion is typically a pH within ± 0.2 units of the target value. Quality‑control labs use a calibrated glass‑electrode pH meter at 25 °C, and the measurement is performed within 30 minutes