Talampicillin is a semisynthetic penicillin-class β-lactam antibacterial and an orally administered prodrug of ampicillin. It is the phthalidyl ester of ampicillin and is readily hydrolyzed after absorption to release the active antibacterial agent ampicillin. Talampicillin is identified by CAS No. 47747-56-8, molecular formula C24H23N3O6S, and molecular weight approximately 481.5 g/mol.
For pharmaceutical use, the hydrochloride form is particularly important. Talampicillin Hydrochloride has CAS No. 39878-70-1, molecular formula C24H23N3O6S·HCl, and molecular weight 517.98 g/mol. FDA GSRS identifies Talampicillin Hydrochloride as a distinct ingredient substance, while the Japanese Pharmacopoeia includes an official monograph for Talampicillin Hydrochloride.
Talampicillin is structurally related to ampicillin and belongs to the penicillin family. Its structure contains the characteristic β-lactam ring and a phthalidyl ester group. Esterification of the carboxyl group of ampicillin produces a more lipophilic prodrug suitable for oral administration.
Talampicillin Hydrochloride is officially described in the Japanese Pharmacopoeia as the hydrochloride of the phthalidyl ester of ampicillin. The JP XVIII monograph gives the hydrochloride molecular formula as C24H23N3O6S·HCl and molecular weight 517.98.
After administration, Talampicillin is hydrolyzed to ampicillin. Ampicillin is a β-lactam antibacterial that interferes with bacterial cell-wall synthesis by binding to penicillin-binding proteins and inhibiting the transpeptidation reactions required for peptidoglycan cross-linking.
The resulting disruption of bacterial cell-wall integrity leads to bacterial cell lysis in susceptible organisms.
Talampicillin has historically been used as an oral penicillin antibacterial, including applications involving susceptible bacterial infections. The WHO/ATC classification identifies Talampicillin under J01CA15, within the systemic plain penicillins group.
The compound was developed as an orally administered prodrug of ampicillin to improve oral absorption and bioavailability compared with equivalent doses of ampicillin.
Talampicillin free base has a molecular weight of approximately 481.5 g/mol, while Talampicillin Hydrochloride has a molecular weight of 517.98 g/mol.
The Japanese Pharmacopoeia describes Talampicillin Hydrochloride as a white to light yellow-white powder. It is very soluble in methanol and freely soluble in water and ethanol (99.5).
Talampicillin Hydrochloride has established pharmacopoeial quality-control requirements. JP XVIII controls its potency on an anhydrous basis, expressed as ampicillin activity. The official monograph specifies 600–700 μg of ampicillin potency per mg of anhydrous Talampicillin Hydrochloride.
The JP monograph also controls optical rotation, heavy metals, arsenic, related substances, 2-formylbenzoic acid and water content. The related-substances test limits the total amount of spots other than the principal spot to NMT 5.0%. Water is controlled at NMT 3.0%.
Talampicillin is a semisynthetic penicillin derivative. Pharmaceutical manufacturing requires controlled synthesis of the phthalidyl ester derivative while maintaining the stereochemical integrity of the penicillin nucleus.
For Talampicillin Hydrochloride, manufacturing controls should address β-lactam integrity, related substances, residual process contaminants, water content and potency. The final material should comply with the applicable pharmacopoeial or registered drug-substance specification.
Talampicillin Hydrochloride should be stored in suitable, tightly closed pharmaceutical containers and protected from conditions that could promote degradation of the β-lactam structure.
The JP monograph specifies tight containers for storage.
A pharmaceutical-grade Talampicillin API package may include a Certificate of Analysis, specification sheet, analytical methods, impurity profile, potency results, water-content data, stability information and other quality/regulatory documentation applicable to the intended market.
A qualified Talampicillin API manufacturer in India should maintain strict control over β-lactam chemistry, stereochemical integrity, potency, related substances and water content. For Talampicillin Hydrochloride, alignment with recognized pharmacopoeial requirements provides an important basis for consistent pharmaceutical quality.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Heavy Metals | NMT 20 ppm |
| Individual Impurity | NMT 5.0% |
| Total Impurities | NMT 5.0% |
| Water Content | NMT 3.0% |
| Melting Point | +151° to +171° |