Development of Lacto Calamine Gel as A Carrier for Antifacial Agents: A Novel Dermatological Strategy

The skin, the largest organ of the human body, acts as the primary barrier between the internal environment and the external world. It plays a critical role in immune defense, thermoregulation, sensory perception, and protection against microbial invasion. Despite its protective functions, the skin is susceptible to various disorders, ranging from minor irritations to severe and chronic dermatological conditions. Among these, facial skin disorders—particularly those causing psychological distress—represent a significant yet often underappreciated clinical challenge. Acne vulgaris alone affects approximately 9.4% of the global population, predominantly adolescents and young adults. Its complex pathophysiology and recurrent nature make it particularly difficult to manage effectively (1). Its complex pathophysiology and tendency to recur make acne a particularly difficult condition to treat. Chemical deficiencies, abnormal sebum production, family history, environmental contaminants, and microbes are some chronic causes contributing to the increased occurrence of breakouts, alongside additional encounters with skin lesions. Epidermal Staphylococcus epidermidis, Propionibacterium (formerly acnes), as well as additional bacterial species, have been linked to the inflammatory events that exacerbate these disorders. Furthermore, the worldwide incidence of facial skin disorders has increased due to challenges associated with contemporary culture, such as poor diets, a great deal of cosmetics, and fluctuating hormones. This underscores the pressing demand for secure, successful, and reasonably priced epidermal treatments (2). Conventional treatments include benzoyl peroxide, retinoids, topical antibiotics, and hormonal therapies are among the mainstay of classical treatment approaches to treat frontal skin lesions (3). Although these medicines have demonstrated efficacy, long-term use is frequently linked to a variety of adverse effects, such as swelling, dehydration, itchiness, photosensitive reactions, and—most alarmingly—the emergence of germ resistance. Despite their effectiveness, systemic antibiotics carry the risk of liver harm, liver damage, along with digestive tract issues. In addition, a lot of topical medicines have drawbacks such as inadequate skin absorption, uneven bioavailability, and failure to comply because of the risk of soreness as aesthetic inadmissibility (4). The multifaceted character of acne necessitates a treatment plan that targets the related indicators, including irritation, excessive oil production, and plugged pores, in addition to the microbiological origin. In an attempt to improve medical results and reduce adverse events, we are seeing an increasing trend towards the creation of multipurpose preparations that may concentrate on multiple therapeutic pathways at once. Throughout many years, lactic calamine became a popular active preparation in dermatology, particularly in the Indian subcontinent. Copper oxide and kaolin, a common ceramic mineral, are two of the main components as well, and both have unique dermatological properties. The primary purpose of kaolin is to absorb oil, and it also soothes sensitive skin. It is perfect for oily and acne-prone skin because it has purifying and adsorptive qualities. In contrast, the substance zinc oxide has sharp, antibacterial, and soothing properties (5). It aids in skin relaxation, discomfort reduction, as well as the formation of an inhibitor that stops further microbial penetration. Kaolin and zinc oxide—well-known for their dermatological benefits—are the key components of Lacto Calamine, a topical formulation widely used in the Indian subcontinent (6). The element zinc oxide possesses antimicrobial, antibacterial, as well as preserving properties, whereas bentonite is a calming as well as oil-absorbing ingredient that is perfect healthy face vulnerable to breakouts. Lacto Calamine is still neglected as a medication delivery vehicle, despite its well-established application. It is a promising option for delivering pharmacologically active chemicals in skincare therapy because of its robust toxicological profile and biological advantages (7). Numerous facial skin disorders, including rosacea, acne, hyperpigmentation, and microbiological infections, are treated using antifacial medications. Drugs like clindamycin, antifungals like ketoconazole, anti-inflammatory substances like lactic acid, and herbal remedies like tea tree oil are examples of these substances (8). A good carrier system that guarantees stability, targeted distribution, & acceptance by patients is essential for effective topical treatment. For long-term issues, including breakouts, standard lotions and cosmetics often do not provide concentrated activity and lasting absorption. In this regard, Lacto Calamine gel provides a novel and user-friendly infrastructure that can enhance the effectiveness of antifacial medications. There are several medicinal benefits to adding these substances to a lactocalamine gel. While zinc oxide aids in lowering inflammation and microbial activity, the kaolin component promotes detox and sebum regulation. Because the gel form is hydrophilic, it improves cutaneous medication distribution, digestion speed, & appearance, all of which improve the user interaction (9). Improved medication solubility and stability, prolonged action at the target site, less irritation, and less systemic side effects are all made possible by this method. Despite the effectiveness of lactocalamine and antifacial medicines alone, their combination has not received much attention. The goal of this research is to combine these and use their respective beneficial properties to create a sturdy, aesthetically pleasing gel (10). Lacto Calamine is a good choice for innovative dermatitis solutions because of its shown safety profile, physiological inactivity, and compatibility across hydrophobic and hydrophilic medications. The study's main objectives are to examine antibacterial efficacy, enhance gel properties such as pH, viscosity, spreadability, and drug release, and assess preformulation adaptability. The aim was to develop an oral solution that is available, economical, and reliable for a wide range of dermatitis applications. If effective, this strategy might enhance clinical results, lessen side effects, increase adherence, and launch a profitable aesthetic item (11).

1. MATERIAL AND METHOD

2.1 Materials

The Lacto Calamine-based gel's composition elements were chosen for their complementary medicinal and formulation-enhancing qualities. The foundation was with calamine lotion, which has antibacterial, calming, and oil-absorbing properties and contains kaolin and zinc oxide. This ingredient functioned as a keratolytic and anti-inflammatory substance to help clear holes and diminish irritation, although clindamycin phosphate was added as an efficient antiseptic to fight germs that cause acne. The inclusion of tea tree oil was motivated by its broad-spectrum antibacterial action and its ability to detoxify the skin. Glycerin was utilised as a humectant to hold onto moisture, triethanolamine was used to modify the acidity and promote the development of gels, and then Carbopol 940 was used as the gelling agent to provide the desired consistency. Ethanol and distilled water were employed as solvents to guarantee that the materials were properly dissolved and blended (12).

The following materials, as given in Table.1, were used in the formulation:

2.2 Formulation of Clindamycin Phosphate Containing Lacto Calamine Gel

The Lacto Calamine-based gel was prepared by dispersing 0.5% Carbopol 940 in distilled water with continuous stirring and allowing it to hydrate for 2-3 hours. After swelling, 2% glycerin was added as a humectant. Clindamycin phosphate (in water), salicylic acid, and tea tree oil (in ethanol) were dissolved based on solubility and incorporated into the gel base under constant stirring. Lacto Calamine lotion was then mixed in, and the pH was adjusted to 6.0 – 6.5 using triethanolamine. The final gel was homogenized and stored in airtight containers at room temperature, see the table.2, that are given below.

2. Preformulation Studies

Preformulation studies were conducted to evaluate the physicochemical compatibility between the active pharmaceutical ingredients—clindamycin phosphate, salicylic acid, and tea tree oil—and the Lacto Calamine gel base, which primarily contains kaolin and zinc oxide. These studies are critical to ensure that no interactions occur that could compromise the stability, efficacy, or safety of the final formulation (13).

3.1 FTIR Spectroscopy

Fourier Transform Infrared (FTIR) spectroscopy, mentioned in figure.1 and table.3, was performed using a KBr pellet method. The FTIR spectra of the pure drugs, Lacto Calamine base, and the physical mixtures of drugs with excipients were recorded in the wavelength range of 4000–400 cm?¹. The purpose was to detect any significant chemical interactions through shifts, disappearance, or the appearance of new peaks in the functional group region (14).

3.2 Interpretation of FTIR

The characteristic peaks of clindamycin phosphate (N-H stretch, C=O stretch), salicylic acid (O-H stretch, C=O carboxylic group, aromatic C=C stretch), and tea tree oil (C-H stretching of methyl/methylene groups) were observed distinctly in both the pure compounds and their mixtures with excipients. The FTIR spectra of the physical mixtures showed no significant alterations or new peak formations, indicating no chemical interaction between the drugs and the gel base components such as Carbopol 940, glycerin, and Lacto Calamine (15).

Figure.1 FTIR analysis of pure drug, excipient, and drug + excipient mixture

Evaluation Of Formulated Gels

The Lacto Calamine-based gel formulations (F1–F4) were evaluated for their physical, chemical, and microbiological properties to assess their effectiveness and stability for topical application. Parameters such as physical appearance, pH, viscosity, spreadability, drug content, antimicrobial activity, and short-term stability were examined. All formulations exhibited smooth, homogeneous texture and a skin-friendly pH (6.0–6.5). Drug content was uniformly distributed (>98%) across all batches. Antimicrobial studies showed effective action against Staphylococcus aureus and E. coli, with F3 demonstrating the highest efficacy. Stability studies over 30 days revealed no signs of separation or degradation, confirming the overall suitability of the gels (16).

3.3 Physical Appearance

All Lacto Calamine gel formulations were examined visually for their color, consistency, and overall appearance. Each batch appeared smooth, off-white, and uniformly blended, with no signs of grittiness, phase separation, or lumps. The homogenous texture and aesthetic appeal suggest good formulation stability and user acceptability for topical application (17).

3.4 pH Measurement

The pH of the formulated gels was determined using a calibrated digital pH meter. All formulations exhibited pH values within the range of 6.0 to 6.5, which falls within the acceptable limit for topical application and is considered non-irritating and compatible with skin pH. This indicates the formulations are safe and suitable for routine dermatological use (18).

3.5 Spreadability

The spreadability of the prepared Lacto Calamine-based gels was evaluated using the slip and drag method to determine ease of application. An ideal topical formulation should spread smoothly with minimal effort, ensuring even distribution on the skin. Among all the formulations (F1–F4), Formulation F3 demonstrated the best spreadability, indicating its excellent user-friendliness. It spread uniformly without requiring excessive pressure and did not leave any greasy or sticky residue. This property makes F3 particularly suitable for facial application, where a light, non-heavy texture is preferred for enhanced comfort, better absorption, and improved patient compliance in daily skincare routines (19).

3.6 Drug Content Uniformity

To assess the uniformity of drug distribution, a fixed quantity of each gel formulation was analyzed using UV spectrophotometry. The results revealed that all formulations (F1–F4) contained more than 98% of the intended drug content, indicating excellent uniformity and consistency within the gel matrix. The high percentage of drug content confirms that the active pharmaceutical ingredients were properly incorporated and evenly dispersed throughout the formulation. This ensures accurate dosing, therapeutic effectiveness, and batch-to-batch reproducibility, which are essential for maintaining the quality and reliability of the topical gel for clinical or cosmetic use (20).

3.7 Antimicrobial Activity

The antimicrobial activity of the Lacto Calamine-based gel formulations (F1–F4) was assessed using the agar well diffusion method against two common skin pathogens: Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative). This method involved preparing nutrient agar plates inoculated with standardized bacterial suspensions, followed by introducing wells containing equal amounts of each gel formulation (21). After incubation, the zone of inhibition surrounding each well was measured to evaluate the antibacterial effectiveness. All formulations demonstrated varying degrees of antimicrobial activity, with visible zones of inhibition indicating effective bacterial growth suppression. Among the tested formulations, F3 exhibited the largest and most well-defined zones of inhibition against both bacterial strains. The enhanced antimicrobial activity of F3 is likely due to the optimal concentration of tea tree oil, known for its broad-spectrum antimicrobial properties, combined with uniform dispersion of clindamycin phosphate and salicylic acid. These results suggest that F3 possesses enhanced antimicrobial efficacy and is highly suitable for acne-prone and infected skin conditions.

3.8 Stability Study

All gel formulations (F1–F4) were stored at room temperature (25?±?2°C) for 30 days to assess their short-term stability. During this period, the formulations were periodically examined for any physical or chemical changes, including color, texture, phase separation, and pH variation. Throughout the observation period, no noticeable changes were detected in terms of color, consistency, or phase separation, and the pH remained stable within the acceptable range. These findings confirm that the formulations maintained their integrity, homogeneity, and therapeutic potential, indicating good short-term stability suitable for topical dermatological use, see the table.4, which is given below.